[Federal Register Volume 77, Number 142 (Tuesday, July 24, 2012)]
[Notices]
[Pages 43382-43405]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-17735]
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NUCLEAR REGULATORY COMMISSION
[Docket No. 50-336; NRC-2012-0158]
Millstone Power Station, Unit 2; Exemption
1.0 Background
Dominion Nuclear Connecticut, Inc., (the licensee, Dominion) is the
holder of Renewed Facility Operating License No. DPR-65, which
authorizes operation of the Millstone Power Station, Unit 2 (MPS2). The
license provides, among other things, that the facility is subject to
all rules, regulations, and orders of the U.S. Nuclear Regulatory
Commission (NRC or the Commission) now or hereafter in effect.
MPS2 shares the site with Millstone Power Station Unit 1, a
permanently defueled boiling water reactor nuclear unit, and Millstone
Power Station Unit 3, a pressurized water reactor. The facility is
located in Waterford, Connecticut, approximately 3.2 miles west
southwest of New London, CT. This exemption applies to MPS2 only. The
other units, Units 1 and 3, are not part of this exemption.
2.0 Request/Action
Title 10 of the Code of Federal Regulations (10 CFR) 50.48,
requires that nuclear power plants that were licensed before January 1,
1979, satisfy the requirements of 10 CFR Part 50, Appendix R, ``Fire
Protection Program for Nuclear Power Facilities Operating Prior to
January 1, 1979,'' Section III.G, ``Fire protection of safe shutdown
capability.'' MPS2 was licensed to operate prior to January 1, 1979. As
such, the licensee's Fire Protection Program (FPP) must provide the
established level of protection as intended by Section III.G of 10 CFR
Part 50, Appendix R.
By letter dated June 30, 2011, ``Request for Exemption from 10 CFR
Part 50, Appendix R, Section III.G, Fire Protection of Safe Shutdown
Capability'' available at Agencywide Documents Access and Management
System (ADAMS), Accession No. ML11188A213, and supplemented by letter
dated February 29, 2012, ``Response to Request for Additional
Information Request for Exemption from 10 CFR Part 50, Appendix R,
Section III.G, Fire Protection of Safe Shutdown Capability'' (ADAMS
Accession No. ML12069A016), the licensee requested an exemption for
MPS2, from certain technical requirements of 10 CFR Part 50, Appendix
R, Section III.G.2 (III.G.2) for the use of operator manual actions
(OMAs) in lieu of meeting the circuit
[[Page 43383]]
separation and protection requirements contained in III.G.2 for fire
areas:
R-2/Fire Hazards Analysis (FHA) Zone A-8C, Zone A-8D, Zone A-13, Zone
T-8, Zone T-10;
R-4/FHA Zone A-6A, Zone A-6B;
R-5/FHA Zone A-8A;
R-6/FHA Zone A-3;
R-7/FHA Zone A-15;
R-8/FHA Zone A-16;
R-9/FHA Zone A-20;
R-10/FHA Zone A-21;
R-12/FHA Zone T-4;
R-13/FHA Zone T-6;
R-14/FHA Zone T-7, Zone T-9;
R-15/FHA Zone C-1;
R-17/FHA Zone A-10A, Zone A-10B, and Zone A-10C.
3.0 Discussion
Pursuant to 10 CFR 50.12, the Commission may, upon application by
any interested person or upon its own initiative, grant exemptions from
the requirements of 10 CFR Part 50 when: (1) The exemptions are
authorized by law, will not present an undue risk to public health or
safety, and are consistent with the common defense and security; and
(2) when special circumstances are present. The licensee has stated
that special circumstances are present in that the application of the
regulation in this particular circumstance is not necessary to achieve
the underlying purpose of the rule, which is consistent with the
language included in 10 CFR 50.12(a)(2)(ii). The licensee further
states that the OMAs included in the exemption request provide
assurance that one train of systems necessary to achieve and maintain
hot shutdown will remain available in the event of a fire.
In accordance with 10 CFR 50.48(b), nuclear power plants licensed
before January 1, 1979, are required to meet Section III.G, of 10 CFR
Part 50, Appendix R. The underlying purpose of Section III.G of 10 CFR
Part 50, Appendix R, is to ensure that the ability to achieve and
maintain safe shutdown is preserved following a fire event. The
regulation intends for licensees to accomplish this by extending the
concept of defense-in-depth to:
a. Prevent fires from starting;
b. Rapidly detect, control, and extinguish promptly those fires
that do occur;
c. Provide protection for structures, systems, and components
important to safety so that a fire that is not promptly extinguished by
the fire suppression activities will not prevent the safe shutdown of
the plant.
The stated purpose of III.G.2 is to ensure that in the event of a
fire, one of the redundant trains necessary to achieve and maintain hot
shutdown conditions remains free of fire damage. III.G.2 requires one
of the following means to ensure that a redundant train of safe
shutdown cables and equipment is free of fire damage, where redundant
trains are located in the same fire area outside of primary
containment:
a. Separation of cables and equipment by a fire barrier having a 3-
hour rating;
b. Separation of cables and equipment by a horizontal distance of
more than 20 feet with no intervening combustibles or fire hazards and
with fire detectors and an automatic fire suppression system installed
in the fire area; or
c. Enclosure of cables and equipment of one redundant train in a
fire barrier having a 1-hour rating and with fire detectors and an
automatic fire suppression system installed in the fire area.
The licensee stated that the OMAs addressed in the exemption
request are those contained in the MPS2 Appendix R Compliance Report.
The licensee stated that the MPS2 Appendix R Compliance Report was
submitted to the NRC for review on May 29, 1987 (ADAMS Legacy Library
Accession No. 8706120088, available at NRC Public Document Room) and
found acceptable by an NRC safety evaluation report (SER) dated July
17, 1990 (ADAMS Accession No. ML012880391), but that the SER did not
specifically address the OMAs.
Each OMA included in this review consists of a sequence of tasks
that need to be performed in various fire areas. The OMAs are initiated
upon confirmation of a fire in a particular fire area. Table 1 lists
the OMAs included in this review (OMAs are listed in the order they are
conducted for a fire originating in a particular area). Some OMAs are
listed more than once, if they are needed for fires that originate in
different areas.
Table 1
----------------------------------------------------------------------------------------------------------------
Area of fire origin Area name Actions OMA
----------------------------------------------------------------------------------------------------------------
Fire Area R-2................... West Penetration Area, Pull Control Power Fuses and OMA 12
Motor Control Center Ensure Breaker A305 is Open.
B61, and the Facility
Z2 Upper 4.16kV
Switchgear Room and
Cable Vault.
Operate Valve 2-MS-190A to OMA 10
Transition from Main Steam Safety
Valves.
Check Local Condensate Storage OMA 20
Tank Level Indication at LIS-5489.
Open Breaker to Fail Valve 2-CH- OMA 6
517 Closed.
Check Local Level Indication at LI- OMA 18
206A.
Check Local Boric Acid Storage OMA 19
Tank Level Indication at LI-208A.
Open Valve 2-CH-429 to Establish OMA 2
Charging Flow Path.
Open Valve 2-CH-192 to Establish OMA 1
Charging Pump Suction from
Refueling Water Storage Tank.
Open Valve 2-CS-13.1B to Establish OMA 8
Charging Pump Suction from
Refueling Water Storage Tank.
----------------------------------------------------------------------------------------------------------------
Fire Area R-4................... Charging Pump Cubicles.. Control at Panel C-10 Until Loss OMA 11
of Air, Operate Valve 2-MS-190B
to Transition from Main Steam
Safety Valves.
Open Valve 2-CH-192 to Establish OMA 1
Charging Pump Suction from
Refueling Water Storage Tank.
----------------------------------------------------------------------------------------------------------------
Fire Area R-5................... ``A'' Safeguards Room Operate Valve 2-MS-190A to OMA 10
(High Pressure Safety Transition from MSSVs.
Injection/Low Pressure
Safety Injection).
[[Page 43384]]
Open Valve 2-CH-192 to Establish OMA 1
Charging Pump Suction from
Refueling Water Storage Tank.
----------------------------------------------------------------------------------------------------------------
Fire Area R-6................... ``B'' Safeguards Room Operate Valve 2-MS-190A to OMA 10
(Low Pressure Safety Transition from Main Steam Safety
Injection). Valves.
Open Valve 2-CH-192 to Establish OMA 1
Charging Pump Suction from
Refueling Water Storage Tank.
----------------------------------------------------------------------------------------------------------------
Fire Area R-7................... Diesel Generator Room A. Control at Panel C-10 Until Loss OMA 11
of Air, Operate Valve 2-MS-190B
to Transition from Main Steam
Safety Valves.
Open Valve 2-CH-508 to Obtain OMA 4
Charging Pump Suction from Boric
Acid Storage Tank.
Open Valve 2-CH-509 to Obtain OMA 5
Charging Pump Suction from Boric
Acid Storage Tank.
Open Valve 2-CH-192 to Establish OMA 1
Charging Pump Suction from
Refueling Water Storage Tank.
----------------------------------------------------------------------------------------------------------------
Fire Area R-8................... Diesel Generator Room B. Operate Valve 2-MS-190A to OMA 10
Transition from Main Steam Safety
Valves.
Open Valve 2-CH-192 to Establish OMA 1
Charging Pump Suction from
Refueling Water Storage Tank.
Check Local Condensate Storage OMA 20
Tank Level Indication at LIS-5489.
----------------------------------------------------------------------------------------------------------------
Fire Area R-9................... Facility Z1 Direct Open Valve 2-CH-508 to Obtain OMA 4
Current Switchgear Room Charging Pump Suction from Boric
and Battery Room. Acid Storage Tank.
Open Valve 2-CH-509 to Obtain OMA 5
Charging Pump Suction from Boric
Acid Storage Tank.
----------------------------------------------------------------------------------------------------------------
Fire Area R-10.................. Facility Z2 Direct Check Local Condensate Storage OMA 20
Current Equipment Room Tank Level Indication at LIS-5489.
and Battery Room.
Check Local Boric Acid Storage OMA 18
Tank Level Indication at LI-206A.
Check Local Boric Acid Storage OMA 19
Tank Level Indication at LI-208A.
----------------------------------------------------------------------------------------------------------------
Fire Area R-12.................. Turbine Driven Auxiliary Operate Valve 2-MS-190A to OMA 10
Feedwater Pump Pump Pit. Transition from Main Steam Safety
Valves.
Open Valve 2-CH-192 to Establish OMA 1
Charging Pump Suction from
Refueling Water Storage Tank.
----------------------------------------------------------------------------------------------------------------
Fire Area R-13.................. West (Facility Z1) 480 Operate Valve SV-4188 from Panel C- OMA 22
VAC Switchgear Room. 10.
Operate Speed Control Circuit H-21 OMA 17
from Panel C-10 to Control
Turbine Driven Auxiliary
Feedwater Pump Speed.
Check Local Condensate Storage OMA 20
Tank Level Indication at LIS-5489.
Pull Control Power Fuses and OMA 16
Ensure Breaker A406 is Open.
Close Breaker DV2021 at Panel DV20 OMA 24
Open Valve 2-CH-508 to Obtain OMA 4
Charging Pump Suction from Boric
Acid Storage Tank.
Open Valve 2-CH-509 to Obtain OMA 5
Charging Pump Suction from Boric
Acid Storage Tank.
Operate Pump P18C from Panel C-10. OMA 21
----------------------------------------------------------------------------------------------------------------
Fire Area R-14.................. Facility Z1 Lower 4.16kV Open Valve 2-CH-508 to Obtain OMA 4
Switchgear Room and Charging Pump Suction from Boric
Cable Vault. Acid Storage Tank.
Open Valve 2-CH-509 to Obtain OMA 5
Charging Pump Suction from Boric
Acid Storage Tank.
Pull Control Power Fuses and OMA 14
Ensure Breaker A410 is Open to
Isolate Required Bus.
Pull Control Power Fuses and OMA 13
Ensure Breaker A408 is Open to
Isolate Required Bus.
Pull Control Power Fuses and OMA 23
Ensure Breaker A401 is Closed to
Power Bus from the Emergency
Diesel Generator.
Pull Control Power Fuses and OMA 15
Ensure Breaker A411 is Open to
Isolate Required Bus.
Close Breaker DV2021 at Panel DV20 OMA 24
----------------------------------------------------------------------------------------------------------------
Fire Area R-15.................. Containment Building.... Operate Valve 2-MS-190A to OMA 10
Transition from Main Steam Safety
Valves.
[[Page 43385]]
Control at Panel C-10 Until Loss OMA 11
of Air, Operate Valve 2-MS-190B
to Transition from Main Steam
Safety Valves.
Open Breaker to Fail Valve 2-CH- OMA 6
517 Closed.
Open Breaker to Fail Valve 2-CH- OMA 7
519 Open to Establish Charging
Flow Path.
Open Valve 2-CH-192 to Establish OMA 1
Charging Pump Suction from
Refueling Water Storage Tank.
----------------------------------------------------------------------------------------------------------------
Fire Area R-17.................. East Penetration Area... Control at Panel C-10 Until Loss OMA 11
of Air, Operate Valve 2-MS-190B
to Transition from Main Steam
Safety Valves.
Open Valve 2-CH-508 to Obtain OMA 4
Charging Pump Suction from Boric
Acid Storage Tank.
Open Valve 2-CH-509 to Obtain OMA 5
Charging Pump Suction from Boric
Acid Storage Tank.
Open Valve 2-CH-192 to Establish OMA 1
Charging Pump Suction from
Refueling Water Storage Tank.
----------------------------------------------------------------------------------------------------------------
The designation Z1 and Z2 are used throughout this exemption. The
licensee stated that the 4.16 kV subsystems are divided into two
specific ``Facilities'' and that Facility Z1 or Z1 Power begins with
load center 24C which powers one train of Engineered Safety Features
(ESFs) and is provided with an emergency power supply by the ``A''
Emergency Diesel Generator (EDG) while Facility Z2 begins with load
center 24D and powers a redundant second train of ESF and is provided
with an emergency power supply by the ``B'' EDG. The licensee also
stated that vital power and control cables fall mainly into two
redundancy classifications; Channel Z1 and Channel Z2 and that in a few
cases there is also a Channel Z5, which is a system that can be
transferred from one source to another. The licensee further stated
that, Facility Z1 would be synonymous with ``A'' train while Facility
Z2 would be synonymous with ``B'' train.
The licensee stated that their exemption request is provided in
accordance with the information contained in Regulatory Issue Summary
(RIS) 2006-10, ``Regulatory Expectations with Appendix R Paragraph
III.G.2 Operator Manual Actions,'' which states that an approved 10 CFR
50.12 exemption is required for all OMAs, even those accepted in a
previously issued NRC SER.
Dominion has requested an exemption from the requirements of
III.G.2 for MPS2 to the extent that one of the redundant trains of
systems necessary to achieve and maintain hot shutdown is not
maintained free of fire damage in accordance with one of the required
means, for a fire occurring in the following fire areas:
R-2 West Penetration Area, Motor Control Center (MCC) B61, and the
Facility Z2 Upper 4.16kV Switchgear Room and Cable Vault;
R-4 Charging Pump Cubicles;
R-5 ``A'' Safeguards Room;
R-6 ``B'' Safeguards Room;
R-7 Diesel Generator Room ``A'';
R-8 Diesel Generator Room ``B'';
R-9 Facility Z1 DC Switchgear Room and Battery Room;
R-10 Facility Z2 DC Switchgear Room and Battery Room;
R-12 Turbine Driven Auxiliary Feedwater Pump Pit;
R-13 West 480 VAC Switchgear Room;
R-14 Facility Z1 Lower 4.16kV Switchgear Room and Cable Vault;
R-15 Containment Building;
R-17 East Penetration Area.
The licensee stated that the OMAs are credited for the III.G.2
deficiencies, such as having only a single safe shutdown train, lack of
separation between redundant trains, lack of detection and automatic
suppression in the fire area or a combination of those deficiencies.
The NRC staff notes that having only a single safe shutdown train is
not uncommon to this plant design. Single train systems at MPS2 include
Instrument Air (IA), ``A'' and ``B'' Boric Acid Storage Tank (BAST)
Control Room (CR) level indication, Condensate Storage Tank (CST) CR
level indication, suction-side flow to the Charging Pumps from the
Refueling Water Storage Tank (RWST), auxiliary spray to the
Pressurizer, and Charging Pump discharge to the Reactor Coolant System
(RCS).
The licensee also stated that they have evaluated/modified all
motor operated valves (MOVs) relied upon by OMAs consistent with NRC
Information Notice (IN) 92-18 (February 28, 1992) which detailed the
potential for fires to damage MOVs that are required for safe shutdown
so that they can no longer be remotely or manually operated and that as
a result of this evaluation and modifications, the possibility that the
desired result was not obtained is minimized. The licensee further
stated that all the equipment operated to perform these OMAs are not
fire affected and therefore are reasonably expected to operate as
designed with one exception being in fire area R-4 concerning the
performance of OMA 1 (see section 3.2.4.1.1) The licensee further
stated that valve 2-CH-192 could be fire affected, however, it is an
(air operated valve (AOV) that fails closed on loss of IA or power and
is normally closed and that a fire event in this area will not cause
this valve to be driven beyond its stops and that the valve will not be
overtourqued. The licensee further stated that operating valve 2-CH-192
is not required until the BASTs are nearly depleted; a minimum of 72
minutes after charging is reestablished (which is not required until
180 minutes) and that a fire directly impacting valve 2-CH-429 would
result in the valve failing in the desired open position.
In their submittals, the licensee described elements of their FPP
that provide their justification that the concept of defense-in-depth
that is in place in the above fire areas is consistent with that
intended by the regulation. To accomplish this, the licensee utilizes
various protective measures to accomplish the concept of defense-in-
depth. Specifically, the licensee stated that the purpose of their
request was to credit the use of OMAs, in conjunction with other
defense-in-depth features, in lieu of the separation and protective
measures required by III.G.2. Their approach is discussed below.
The licensee provided an analysis that described how fire
prevention is addressed for each of the fire areas for which the OMAs
may be required.
[[Page 43386]]
Unless noted otherwise below, all of the fire areas included in this
exemption have a combustible fuel load that is considered to be low,
with fuel sources consisting primarily of fire retardant cable
insulation and limited floor based combustibles. The licensee also
stated that two of the fire areas (R-7/FHA Zone A-15 and R-8/FHA Zone
A-16) have high combustible loading consisting of fuel oil and lube oil
and that automatic pre-action fire suppression systems are provided in
these areas. The licensee further stated that two other fire areas (R-
17/FHA Zone A-10A and R-12/FHA Zone T-4) contain negligible combustible
loading, with combustibles in these areas consisting of Class A
combustibles and lube oil. There are no high energy ignition sources
located in the areas except as noted in fire areas R-2 and R-14. The
fire areas included in the exemption request are not shop areas so hot
work activities are infrequent with administrative control (e.g., hot
work permits, fire watch, and supervisory controls) programs in place
if hot work activities do occur. The administrative controls are
described in the Millstone FPP, which is incorporated into the Updated
Final Safety Analysis Report.
The licensee stated that the storage of combustibles is
administratively controlled by the site's FPP procedures to limit the
effects of transient fire exposures on the plant and in addition, hot
work (i.e., welding, cutting, grinding) is also administratively
controlled by site FPP procedure CM-AA-FPA-100.
The licensee indicated that their FPP uses the concept of defense-
in-depth, both procedurally and physically, to meet the following
objectives: 1. Prevent fires from starting; 2. Rapidly detect, control,
and extinguish promptly, those fires that do occur; and, 3. Provide
protection for structures, systems, and components important to safety
so that a fire that is not promptly extinguished by the fire
suppression activities will not prevent the safe shutdown of the plant.
The licensee also stated that the integration of the program,
personnel, and procedures, which are then collectively applied to the
facility, reinforce the defense in-depth aspect of the FPP and that
strict enforcement of ignition source and transient combustible control
activities (through permitting), and monthly fire prevention
inspections by the site Fire Marshal ensure that this work is actively
monitored to prevent fires.
The MPS Fire Brigade consists of a minimum of a Shift Leader and
four Fire Brigade personnel. The affected unit (MPS2 or MPS3) supplies
an advisor, who is a qualified Plant Equipment Operator (PEO). The
advisor provides direction and support concerning plant operations and
priorities. Members of the Fire Brigade are trained in accordance with
MPS, Station Procedure TQ-1, Personnel Qualification and Training. Fire
Brigade personnel are responsible for responding to all fires, fire
alarms, and fire drills and to ensure availability, a minimum of a
Shift Leader and four Fire Brigade personnel remain in the Owner
Controlled Area and do not engage in any activity which would require a
relief in order to respond to a fire. The licensee further stated that
the responding Fire Brigade lead may request the Shift Manager (SM)
augment the on-shift five member Fire Brigade with outside resources
from the Town of Waterford Fire Department which has a letter of
agreement with MPS, to respond to the site (when requested) in the
event of a fire emergency or rescue and will attempt to control the
situation with available resources.
MPS2 has been divided into fire areas, as described in the MPS FPP.
Three-hour fire barriers are normally used to provide fire resistive
separation between adjacent fire areas. In some cases, barriers with a
fire resistance rating of less than three hours are credited but
exemptions have been approved or engineering evaluations performed in
accordance with Generic Letter 86-10 to demonstrate that the barriers
are sufficient for the hazard. Walls separating rooms within fire areas
are typically constructed of heavy concrete. The licensee stated that
in general, fire rated assemblies separating Appendix R fire areas meet
Underwriters Laboratories/Factory Mutual (UL/FM) design criteria and
the requirements of American Society of Testing Materials (ASTM) E-119,
``Fire Test of Building Construction and Materials'' for 3-hour rated
fire assemblies. The licensee also stated that openings created in fire
rated assemblies are sealed utilizing penetration seal details that
have been tested in accordance with ASTM E-119 and are qualified for a
3-hour fire rating, in addition, fireproof coating of structural steel
conforms to UL-Listed recognized details and is qualified for a 3-hour
fire rating. The licensee further stated that fire dampers are UL-
Listed and have been installed in accordance with the requirements of
National Fire Protection Association (NFPA) 90A, ``Standard for the
Installation of Air Conditioning and Ventilation Systems,'' and that
the code of record for fire dampers is either the version in effect at
the time of original plant construction (late 1960s) or the 1985
edition. The licensee further stated that fire doors are UL-Listed and
have been installed in accordance with NFPA 80, ``Standard for Fire
Doors and Windows'' in effect at the time of plant construction (late
1960s).
The licensee provided a discussion of the impacts of any Generic
Letter (GL) 86-10 evaluations and/or exemptions on the fire areas
included in this exemption request. For all the areas with GL 86-10
evaluations and/or other exemptions, the licensee stated that none of
the issues addressed by the evaluations would adversely impact, through
the spread of fire or products of combustion, plant areas where OMAs
are performed or the respective travel paths necessary to reach these
areas. The licensee also stated that there are no adverse impacts on
the ability to perform OMAs and that the conclusions of the GL 86-10
evaluations and the exemption requests would remain valid with the OMAs
in place. In addition to these boundaries, the licensee provided a
hazard analysis that described how detection, control, and
extinguishment of fires are addressed for each of the fire areas for
which the OMAs may be needed.
Unless noted otherwise below, fire areas are provided with
ionization smoke detectors. The licensee stated that the smoke and heat
detection systems were designed and installed using the guidance of the
requirements set forth in several NFPA standards including the 1967,
1979, and 1986 Editions of NFPA 72D, ``Standard for the Installation,
Maintenance and Use of Proprietary Protective Signaling Systems for
Watchman, Fire Alarm and Supervisory Service,'' and the 1978 and 1984
Editions of NFPA 72E, ``Standard on Automatic Fire Detectors.'' Upon
detecting smoke or fire, the detectors initiate an alarm in the CR
enabling Fire Brigade response. The licensee stated that in most cases,
no automatic fire suppression systems are provided in the areas
included in this exemption request except for plant areas with
significant quantities of combustibles, such as lube oil. Automatic
fire suppression systems have also been installed in areas with one-
hour barrier walls and one-hour rated electrical raceway encapsulation.
The licensee stated that fire suppression systems were designed in
general compliance with, and to meet the intent of the requirements of
several NFPA standards depending on the type of system including the
1985 Edition of NFPA 13, ``Standard for the Installation of Sprinkler
Systems,'' the 1985 Edition of NFPA 15, ``Standard for Water Spray
[[Page 43387]]
Fixed Systems For Fire Protection,'' and the 1987 Edition of NFPA 12A,
``Standard on Halon 1301 Fire Extinguishing Systems.''
The licensee stated that in general, fire extinguishers and hose
stations have been installed in accordance with the requirements of the
1968 Edition of NPFA 10, ``Standard for the Installation of Portable
Fire Extinguishers'' and the 1978 Edition of NFPA 14, ``Standard for
the Installation of Standpipe and Hose Systems,'' respectively. The
licensee stated that Equipment Operators are trained Fire Brigade
members and would likely identify and manually suppress or extinguish a
fire using the portable fire extinguishers and manual hose stations
located either in or adjacent to, or both, these fire areas.
Each of the fire areas included in this exemption is analyzed below
with regard to how the concept of defense-in-depth is achieved for each
area and the role of the OMAs in the overall level of safety provided
for each area.
3.1 Fire Area R-2, West Cable Vault, Upper 6.9 and 4.16kV Switchgear
Rooms, 480V MCC B61 and B41A Enclosure, West Piping Penetration Area,
West Electrical Penetration Area
3.1.1 Fire Prevention
The licensee stated that the West Cable Vault, the Upper 6.9 and
4.16 kV Switchgear Room, the 480V MCC B61 and B41A Enclosure, and the
West Piping Penetration Area have low combustible loading that
predominantly consists of cable insulation and that potential ignition
sources for these areas includes electrical faults.
The licensee stated that the West Electrical Penetration Area has
low to moderate combustible loading that includes small amounts of
plastics and cellulosic materials and that potential ignition sources
include electrical faults.
3.1.2 Detection, Control and Extinguishment
The licensee stated that the West Cable Vault is provided with an
automatic wet-pipe sprinkler system designed to protect structural
steel in this area from the adverse affects of a fire, and also
protected by an ionization smoke detection system that alarms at the
main fire alarm panel in the CR. In addition, the licensee stated that
the vertical cable chase that leads down the Auxiliary Building (AB)
cable vault is protected by an automatic deluge spray system which is
actuated by a cross-zoned smoke detection system that alarms at a local
panel and at the main fire alarm panel in the CR. The licensee also
stated that a fire in the West Cable Vault that could potentially
impact a cable of concern would likely involve cable insulation and
result from an electrical fault and that combustibles in this area
consist predominantly of Institute of Electrical and Electronics
Engineers (IEEE) 383 qualified cable insulation or cable that has been
tested and found to have similar fire resistive characteristics (not
self-igniting or capable of propagating flame after pilot ignition
source is removed). The licensee also stated that were a cable fire to
occur in this area, it would be rapidly detected in its incipient stage
by the installed smoke detection system, which will aid in providing
rapid response by the Fire Brigade and that in the unlikely event the
fire advanced beyond its incipient stage, it would actuate the
installed automatic wet-pipe suppression system which consists of
sprinklers located in each beam pocket and provides reasonable
assurance that a cable tray fire in this area will be controlled and
confined to the immediate area of origin, and will limit fire exposure/
damage.
The licensee stated that the Upper 6.9 and 4.16kV Switchgear Room
has ionization smoke detection located directly over each switchgear
cabinet that alarms at the main fire alarm panel in the CR. The
licensee further stated that a fire in the Upper 6.9 and 4.16 kV
Switchgear Room that could potentially impact any cables of concern
would likely involve cable insulation resulting from an electrical
fault or failure of Bus 25B, which is located several feet away from
the subject cable tray and that combustibles in this area consist
predominantly of IEEE 383 qualified cable insulation or cable that has
been tested and found to have similar fire resistive characteristics.
The licensee further stated that in the unlikely event of a fire, it
would be rapidly detected by the ionization smoke detection system
installed in the area and that the smoke detection system, which
consists of an ionization smoke detector located directly over each
switchgear cabinet in the area, will aid in providing prompt Fire
Brigade response.
The licensee stated that the 480V MCC B61 and B41A enclosures are
provided with ionization smoke detection that alarms at a local panel
and at the main fire alarm panel in the CR. The licensee also stated
that the steel enclosure of the MCC room is protected by a wet pipe
water spray system in lieu of a three hour fire barrier. The licensee
further stated that a fire in the 480 V MCC B61 and B41A enclosures
that could potentially impact any cables of concern would likely
involve cable insulation resulting from an electrical fault or failure
of one of the MCC's located in the room and that combustibles in this
area consist predominantly of IEEE 383 qualified cable insulation or
cable that has been tested and found to have similar fire resistive
characteristics. The licensee further stated that a failure of MCC B-
41B could also serve as an ignition source and that an MCC failure
normally results in a high intensity fire that lasts for a short
duration, which makes it unlikely that it will cause sustained
combustion of IEEE 383 qualified cables despite the fact that the
subject cable trays are located approximately 6-8' above the MCC. The
smoke detection system, which consists of an ionization smoke detector
located directly over MCC B61, will aid in providing prompt Fire
Brigade response.
The licensee stated that the West Piping Penetration Area is
provided with an ionization smoke detection system, which alarms at a
local panel and at the main fire alarm panel in the CR. The licensee
further stated that a fire in the West Piping Penetration area that
could potentially impact any cables of concern would likely involve
cable insulation resulting from an electrical fault and that
combustibles in this area consist predominantly of IEEE 383 qualified
cable insulation or cable that has been tested and found to have
similar fire resistive characteristics. The licensee further stated
that since there is a minimal amount of Class A combustibles in this
area, there is little chance of a fire occurring, outside of a
switchgear failure, which could act as a pilot ignition source for the
cable insulation and that a switchgear failure normally results in a
high intensity fire that lasts for a short duration, which makes it
unlikely that it will cause sustained combustion of IEEE 383 qualified
cables. The licensee further stated that in the event of a fire in this
area, it would be rapidly detected in its incipient stage by the
installed smoke detection system, which will aid in providing rapid
response by the Fire Brigade.
The licensee stated that the West Electrical Penetration Area is
provided with an ionization smoke detection system, which alarms at the
main fire alarm panel in the CR. The licensee further stated that a
fire in the West Electrical Penetration Area that could potentially
impact any cables of concern would likely involve cable insulation
resulting from an electrical fault and that combustibles in this area
consist predominantly of IEEE 383 qualified cable insulation or cable
that has been tested and found to have similar fire
[[Page 43388]]
resistive characteristics. The licensee further stated that in the
event of a fire in this area, it would be rapidly detected in its
incipient stage by the installed smoke detection system, which will aid
in providing rapid response by the Fire Brigade.
3.1.3 Preservation and Safe Shutdown Capability
The licensee stated that the OMAs associated with a fire in the
West Cable Vault are related to failure of the feed to the 480V load
center bus 22F or the ``B'' EDGs control and power cables and that loss
of bus 22F results in the loss of the ``B'' battery charger and the
eventual depletion of the ``B'' battery which in turn results in the
loss of level transmitter LT-5282.
The licensee stated that the cables of concern in the Upper 4.16 kV
Switchgear Room are for valves 2-CH-429 and 2-CH-517, level
transmitters LT-5282, LT-206 and LT-208 and breaker A305. The licensee
also stated that the cabling of concern is part of the breaker control
logic and coordination between buses 24C, 24D and 24E and that
components 2-CH-429, 2-CH- 517, LT-5282, LT-206, and LT-208 are single
train components. The licensee further stated that the worst case tray
arrangement is the common tray for components 2-CH-429, 2-CH-517, LT-
206, LT-208 and LT-5282. The licensee further stated that there is a
moderate likelihood that a fire can occur which will impact components
2-CH-429, 2-CH-517, LT-206, LT-208 or LT-5282.
The licensee stated that cables of concern in the 480 V MCC B61 and
B41A enclosures are the power, indication and control cables for valves
2-CS-13.1B and 2-CH-429.
The licensee stated that valve 2-CH-429 is located in the north and
west side of the West Piping Penetration Room, near the containment
building wall and that the power and indication cabling for this valve
is routed via conduit into a cable tray located along the west wall of
the room. The licensee also stated that there is likely no fire that
can occur which will impact valve 2-CH-429 due to configuration,
combustible loading and ignition sources, however, if there was an
impact, the nature of the cables would fail the valve in the desired
open position.
The licensee stated that the cables of concern in the West
Electrical Penetration Area service valves 2-CH-429 and 2-CH-517, and
level transmitters LT-206, LT-208 and LT-5282. The licensee also stated
that it is very unlikely that a fire can occur which will impact valves
2-CH-429 or 2-CH-517 due to configuration, combustible loading, and
ignition sources and that analysis indicates there is a low likelihood
that a fire will impact LT-206, LT-208 and LT-5282.
The licensee stated that a fire in the West Penetration Area, MCC
B61, and the Facility Z2 Upper 4.16 kV Switchgear Room and Cable Vault
will affect all Facility Z2 shutdown components, that Facility Z1 is
used to achieve and maintain Hot Standby, and that an Abnormal
Operating Procedure (AOP) is used to achieve plant shutdown to Hot
Standby. The licensee also stated that for a fire in fire area R-2,
OMAs are required to provide for Decay Heat Removal and to restore
Charging system flow to the RCS.
3.1.4 OMAs Credited for a Fire in This Area
3.1.4.1 Auxiliary Feedwater (AFW) Flow
3.1.4.1.1 OMA 12--Pull Control Power Fuses and Ensure Breaker A305 Is
Open
The licensee stated that in order to establish AFW flow, Bus 24C is
credited to provide power from H7A (``A'' EDG) to P9A (``A'' Motor
Drive Auxiliary Feedwater Pump (MDAFW)) and that calculations conclude
that AFW flow must be established within 45 minutes. The licensee also
stated that cable damage may result in a loss of remote breaker control
capability for A305, which is the Bus 24C to Bus 24E cross-tie breaker
and that at A305 (Bus 24C), the OMA is to de-energize the breaker
control circuit by pulling control power fuses and ensuring that the
breaker is open which prevents spurious closure of A305. The licensee
further stated that this step establishes AFW flow and provides for a
36 minute time margin on the 45 minute time requirement and that after
AFW flow is established, the atmospheric dump valves (ADVs) are
utilized to remove decay heat. The licensee further stated that prior
to this, RCS decay heat removal is provided by utilizing the Main Steam
Safety Valves (MSSVs) and that steaming through the MSSVs is also
acceptable after AFW flow is established but utilizing the ADVs, with
2-MS-190A credited for the fire in fire area R-2, is required for
initiating the transition to Cold Shutdown.
3.1.4.1.2 OMA 10--Operate Valve 2-MS-190A To Transition From MSSVs
The licensee stated that valve 2-MS-190A fails due to a postulated
loss of IA and its cables are not impacted by fire. The licensee also
stated that PEO-2, will remain with the ADV to modulate steam flow per
direction from the CR. Although this OMA is completed in 10 minutes,
since the OMA is conducted after AFW flow and before charging system
flow is established, there is no minimum required completion time.
3.1.4.1.3 OMA 20--Obtain Condensate Storage Tank Level at Local Level
Indicating Switch LIS-5489A
The licensee stated that the remaining decay heat removal function
is to locally monitor CST level (LIS-5489) which is not a short-term
requirement because there is sufficient inventory in the CST to provide
over 10 hours of water flow to the AFW system. The licensee further
stated that this activity will likely be repeated several times over
the course of placing the plant in Cold Shutdown.
3.1.4.2 Charging System Flow
3.1.4.2.1 OMAs 2 and 6--Open Valve 2-CH-429 To Establish Charging Pump
Flow Path and Open Breaker to Fail Valve 2-CH-517 Closed
The licensee stated that the Charging System has several OMAs to
reestablish flow within the three hour required timeframe and that to
initially restore charging, valve 2-CH-429 is opened or verified open
(OMA 2), and valve 2-CH-517 (OMA 6) is closed. The licensee stated that
valve 2-CH-429 is a MOV located in the fire area and will be locally
manually operated postfire and that it has been evaluated with respect
to the guidance contained in NRC IN 92-18. The licensee stated that
valve 2-CH-517 is an AOV that fails closed and is located in
containment. The licensee further stated that the OMA is to de-energize
the power supply (DV20) and fail the valve closed and that once 2-CH-
429 is manually opened, Charging can be reestablished. The licensee
further stated that assuming 60 minutes before being allowed into the
fire affected area, the Charging flow path can be established within 64
minutes and Charging flow within 66 minutes which provides 114 minutes
of margin on the 180 minute required time.
3.1.4.2.2 OMAs 18 and 19--Obtain BAST Level at Local Level Indicator
LI-206A and Obtain BAST Level at Local Level Indicator LI-208A
The licensee stated that due to fire cable damage, both LT-206 and
LT-208 are not available from the CR and that both BAST levels require
OMAs for local level indication at LI-206A (OMA 18) and LI-208A (OMA
19). The licensee also stated that both indicators are outside the R-2
fire area and that the action is considered part of the restoration for
the Charging system and as such, this action is not required until the
three hour timeframe.
[[Page 43389]]
3.1.4.2.3 OMAs 1 and 8--Open Valve 2-CH-192 and Open Valve 2-CS-13.1B
The licensee stated that after Charging is restored, there are OMAs
to switch the Charging suction path from the BASTs to the RWST which
requires opening valves 2-CH-192 (OMA1) and 2-CS-13.1B (OMA 8). The
licensee also stated that the 2-CH-192 valve is an AOV which may have
failed closed due to a loss of IA and that it has a safety-related air
accumulator which provides sufficient air to stroke open the valve and
maintains it open for three hours and that after the air accumulator is
exhausted, the valve will fail closed and an OMA is required to
establish/maintain RWST flow to the Charging system.
The licensee stated that valve 2-CS-13.1B is a MOV which may
spuriously close due to fire cable damage and that it has to be
manually opened in the field prior to switching over to the RWST. The
licensee also stated that based on requirements in the technical
requirements manual (TRM), the BASTs can supply Charging for more than
72 minutes, at which time the Charging pump suction source is shifted
to the RWST.
3.1.4.3 OMA Timing
The OMA to establish AFW flow can be completed in 9 minutes which
provides a 36 minute margin since the required completion time is 45
minutes. The OMA to monitor CST level can be completed in 12 minutes
and is a long term action as the CST provides over 10 hours of
inventory to AFW. The OMAs to establish Charging system flow from the
BASTs can be completed in 66 minutes which provides a 114 minute margin
since the required completion time is 180 minutes. The OMAs to
establish Charging system flow from the RWST prior to BAST depletion
can be completed in 40 minutes which provides a 32 minute margin since
the required completion time is 72 minutes.
3.1.5 Conclusion
Given the limited amount of combustible materials and ignition
sources and installed detection and automatic fire suppression (West
Cable Vault), it is unlikely that a fire would occur and go undetected
or unsuppressed by the personnel, and damage the safe shutdown
equipment. The low likelihood of damage to safe shutdown equipment due
to a fire in this area, combined with the ability of the OMAs to
manipulate the plant in the event of a fire that damages safety
shutdown equipment and be completed with more than 30 minutes of
margin, provides adequate assurance that safe shutdown capability is
maintained.
3.2 Fire Area R-4, Charging Pump Room, Degasifier Area
3.2.1 Fire Prevention
The licensee stated that the Charging Pump Room has low combustible
loading that includes small amounts of lube oil and that potential
ignition sources include electrical faults, pump motors, mechanical
failure, and hot surfaces.
The licensee stated that the Degasifier Area has low combustible
loading that predominantly consists of cable insulation and that
potential ignition sources include electrical faults.
3.2.2 Detection, Control, and Extinguishment
The licensee stated that the Charging Pump Room is provided with an
ionization smoke detection system which alarms at a local panel and at
the main fire alarm panel in the CR. A fixed water curtain is provided
at the entrance to the Degasifier Area (FHA Fire Zone A-6B), which
provides protection for the Charging Pump area from a fire in the
Reactor Building Closed Cooling Water System (RBCCW) Pump and Heat
Exchanger Area (FHA Fire Zone A-1 B). The licensee also stated that
actuation of this system results in an alarm (waterflow) at the main
fire alarm panel in the CR. The licensee further stated that a fire in
the Charging Pump cubicles that could potentially impact any cables of
concern would likely involve cable insulation resulting from an
electrical fault or a lube oil fire resulting from a Charging Pump
failure and that combustibles in this area consist predominantly of
IEEE 383 qualified cable insulation or cable that has been tested and
found to have similar fire resistive characteristics. The licensee also
stated that since there is a minimal amount of Class A combustibles in
this area, there is little chance of a fire occurring which could act
as a pilot ignition source for the cable insulation and that each
charging pump contains just over 10 gallons of lube oil which could
also serve as a pilot ignition source for cable insulation in the event
of a pump/motor failure with the resultant ignition of the lube oil.
The licensee further stated that based on the elevated ignition
temperature of the lube oil and the low probability of a pump/motor
assembly failure with subsequent ignition of the entire quantity of
lube oil, it is unlikely that a lube oil fire from a Charging Pump
failure would serve as an ignition source for IEEE 383 qualified cable
insulation. The licensee further stated that curbs are installed
between each Charging Pump to protect each pump from a combustible
liquid spill within a neighboring Charging Pump cubicle. The licensee
further stated that a fire would be rapidly detected in its incipient
stage by the installed smoke detection system, which will aid in
providing rapid response by the Fire Brigade.
The licensee stated that the Degasifier Area is provided with an
ionization smoke detection system which alarms at a local panel and at
the main fire alarm panel in the CR and that a fixed water curtain is
provided at the entrance to this area and serves to provide protection
for the Charging Pump Room (FHA Zone A-6A) from a fire in the RBCCW
Pump and Heat Exchanger Area (FHA Zone A-1 B). The licensee also stated
that actuation of this system results in an alarm (waterflow) to the
main fire panel in the CR. The licensee further stated that a fire in
the Degasifier Area that could potentially impact any cables of concern
would likely involve cable insulation resulting from an electrical
fault and that combustibles in this area consist predominantly of IEEE
383 qualified cable insulation or cable that has been tested and found
to have similar fire resistive characteristics. The licensee further
stated that since there is a minimal amount of Class A combustibles in
this area, there is little chance of a fire occurring which could act
as a pilot ignition source for the cable insulation. The licensee
further stated that in the event of a fire in this area, it would be
rapidly detected in its incipient stage by the installed smoke
detection system, which will aid in providing rapid response by the
Fire Brigade.
3.2.3 Preservation of Safe Shutdown Capability
The licensee stated that the cables of concern in the Charging Pump
Room are for control and indication of valve 2-CH-192 and that analysis
indicates there is a low likelihood that a fire can occur which will
impact the valve. The licensee stated that the cables of concern for
the Degasifier Area pass through the hallway leading into the area and
are for control and indication of valve 2-CH-192 and that analysis
indicates there is a very low likelihood that a fire can occur which
will impact valve 2-CH-192.
The licensee stated that a fire in the Charging Pump cubicles will
affect the Charging Pumps and several suction valves and that the
compliance strategy relies on re-routing of Facility Z2 control and
power cables for P18B and
[[Page 43390]]
Facility Z2 power cable for P18C from the pump cubicles to outside of
fire area R-4. The licensee also stated that an exemption provides
technical justification of survivability of at least one Charging Pump
following a fire in this area, even though the requirements of III.G.2
are not met. The licensee further stated that survivability is
justified based on existing physical spatial separation, partial height
missile walls, curbing between pumps, and low intervening combustibles
and that plant shutdown can be accomplished using an AOP. The licensee
further stated that OMAs are required to provide for decay heat removal
and to restore Charging system flow to the RCS.
3.2.4 OMAs Credited for a Fire in This Area
3.2.4.1 AFW and Charging System Flow
3.2.4.1.1 OMAs 1 and 11 Open Valve 2-CH-192 and Control Valve 2-MS-190B
at Panel C10 or Local Manual Operation
The licensee stated that establishing AFW flow to the credited
steam generator (SG) is required to be accomplished within 45 minutes
and that the required flow path utilizes the turbine driven auxiliary
feedwater (TDAFW) pump. The licensee also stated that prior to AFW
initiation, the plant is placed in the Hot Standby condition by
steaming through the MSSVs and that after AFW is established from the
CR, operation of the ADV (2-MS-190B) (OMA 11) is the required method of
removing decay heat to maintain Hot Standby and transition to Cold
Shutdown. The licensee further stated that there is no cable damage
from fire to the required ADV (2-MS-190B), however, the fire may cause
a loss of IA which is required to operate the ADVs to support decay
heat removal. The licensee stated that upon a loss of air, the ADV will
fail closed and that this design prevents excessive RCS cooldown prior
to AFW start and, therefore, in the event of a loss of IA, Operators
will establish local manual control of 2-MS-190B after AFW flow is
established. The licensee further stated that PEO-2 will remain with
the ADV to modulate steam flow per direction from the CR and that after
restoration of the Charging system, the BASTs are credited for
maintaining RCS inventory and that the BASTs have a minimum level
specified in the TRM which ensures 72 minutes of flow. The licensee
further stated that once the BASTs are depleted, Operators switch over
to the RWST. The licensee further stated that due to fire damage, the
2-CH-192 valve may spuriously close and that in order to establish the
RWST as the suction path for the Charging system, an OMA is required to
open valve 2-CH-192 (OMA 1) prior to BAST depletion. The licensee
further stated that OMA 1 is performed in the fire affected area and is
performed after the fire is extinguished and after the Station
Emergency Response Organization (SERO) is fully staffed. OMA 1
establishes the RWST as the suction supply for the charging system and
is not conducted until after AFW is established which takes 17 minutes.
The BASTs have a minimum TRM specified inventory to ensure 72 minutes
of flow and OMA 1 can be completed in 32 minutes which results in 40
minutes of margin.
3.2.4.2 OMA Timing
AFW flow is established from the CR within the required 45 minute
time period and should IA be lost, the OMA to continue decay heat
removal can be conducted beginning 17 minutes after AFW flow is
established. The OMA to establish Charging system flow from the RWST
prior to BAST depletion can be completed in 32 minutes which provides a
40 minute margin since the required completion time is 72 minutes.
3.2.5 Conclusion
Given the limited amount of combustible materials and ignition
sources and installed detection and water curtain, it is unlikely that
a fire would occur and go undetected or unsuppressed by the personnel,
and damage the safe shutdown equipment. The low likelihood of damage to
safe shutdown equipment due to a fire in this area, combined with the
ability of the OMAs to manipulate the plant in the event of a fire that
damages safe shutdown equipment and be completed with more than 30
minutes of margin, provides adequate assurance that safe shutdown
capability is maintained.
3.3 Fire Area R-5, ``A'' Safeguards Room (Containment Spray and High
Pressure Safety Injection/Low Pressure Safety Injection Pump Room)
3.3.1 Fire Prevention
The licensee stated that the area has low combustible loading that
includes cable insulation and small amounts of lube oil and that
potential ignition sources include electrical faults, pump motors,
mechanical failure, and hot surfaces.
3.3.2 Detection, Control, and Extinguishment
The licensee stated that the area is provided with an ionization
smoke detection system which alarms at a local panel and at the main
fire alarm panel in the CR. The licensee also stated that a fire in
this area that could potentially impact any cables of concern would
likely involve cable insulation resulting from an electrical fault or a
lube oil fire resulting from a pump and/or motor failure. Combustibles
in this area consist predominantly of IEEE 383 qualified cable
insulation or cable that has been tested and found to have similar fire
resistive characteristics. The licensee further stated that since there
is a minimal amount of Class A combustibles in this fire area, there is
little chance of a fire occurring which could act as a pilot ignition
source for the cable insulation and that while lube oil could also
serve as a pilot ignition source for cable insulation, the small
quantities of lube oil would result in a low intensity fire and based
on the elevated ignition temperature of the lube oil and the low
probability of a pump and/or motor assembly failure with subsequent
ignition of the entire quantity of lube oil, it is unlikely that a lube
oil fire from a pump and/or motor failure would serve as an ignition
source for IEEE 383 qualified cable insulation. The licensee further
stated that in the event of a fire in this area, it would be rapidly
detected in its incipient stage by the installed smoke detection
system, which will aid in providing rapid response by the Fire Brigade.
3.3.3 Preservation of Safe Shutdown Capability
The licensee stated that a fire in the area that could potentially
impact any cables of concern would likely involve cable insulation
resulting from an electrical fault or a lube oil fire resulting from a
pump and/or motor failure and that some Shutdown Cooling system
components would be affected and that plant shutdown to Hot Standby can
be accomplished using existing AOPs.
3.3.4 OMAs Credited for a Fire in This Area
3.3.4.1 AFW and Charging System Flow
3.3.4.1.1 OMAs 1 and 10--Open Valve 2-CH-192 and Operate Valve 2-MS-
190A
The licensee stated that for a fire in fire area R-5, two OMAs are
identified to provide for decay heat removal and restore charging
system flow to the RCS, with the first OMA (OMA 10) being to open and
modulate 2-MS-190A (ADV) and the second OMA (OMA 1) being to open valve
2-CH-192. The licensee also stated that both OMAs are needed to
compensate for a postulated loss of IA
[[Page 43391]]
and that neither valve will experience cable damage due to a fire in
fire area R-5. The licensee further stated that the ADVs are utilized
after AFW flow is established and that AFW is required to be
established within 45 minutes and prior to this, RCS decay heat removal
is provided by utilizing the MSSVs. The licensee further stated that
steaming through the MSSVs is also acceptable after AFW flow is
established, but utilizing the ADVs, with 2-MS-190A credited for a fire
in fire area R-5, is required for maintaining the plant in Hot Standby
and initiating the transition to Cold Shutdown. The licensee further
stated that PEO-2 will remain with the ADV to modulate steam flow per
direction from the CR and that PEO-1 will complete the second OMA by
opening 2-CH-192 to establish the RWST as the source of water to the
RCS. The licensee further stated that 2-CH-192 is an AOV which may have
failed closed due to a loss of IA and that the valve has a safety-
related air accumulator which supplies sufficient air to stroke open
the valve and maintain it open for three hours and that after the air
accumulator is exhausted, the valve will fail closed. The licensee
further stated that the required OMA establishes/maintains RWST flow to
the Charging system and the BASTs have a minimum level specified in the
TRM which ensures Charging flow for more than 72 minutes, at which time
Charging pump suction is shifted to the RWST. The licensee further
stated that calculations indicate that the Charging system must be
restored within three hours, therefore, the accumulator capacity and
the minimum TRM BAST level requirement require the OMA to locally open
2-CH-192 be accomplished within three hours (prior to the air
accumulator being exhausted).
3.3.4.2 OMA Timing
AFW flow is established within the required 45 minute time period
and should IA be lost, the OMA to continue decay heat removal can be
conducted beginning 17 minutes after AFW flow is established. The OMA
to establish Charging system flow from the RWST prior to BAST depletion
can be completed in 32 minutes which provides a 40 minute margin since
the required completion time is 72 minutes.
3.3.5 Conclusion
Given the limited amount of combustible materials and ignition
sources and installed detection, it is unlikely that a fire would occur
and go undetected or unsuppressed by the personnel, and damage the safe
shutdown equipment. The low likelihood of damage to safe shutdown
equipment due to a fire in this area, combined with the ability of the
OMAs to manipulate the plant in the event of a fire that damages safe
shutdown equipment and be completed with more than 30 minutes of
margin, provides adequate assurance that safe shutdown capability is
maintained.
3.4 Fire Area R-6, ``B'' Safeguards Room (Low Pressure Safety Injection
Pump Room)
3.4.1 Fire Prevention
The licensee stated that the area has low combustible loading that
includes cable insulation and small amounts of lube oil and that
potential ignition sources include electrical faults, pump motors,
mechanical failure, and hot surfaces.
3.4.2 Detection, Control, and Extinguishment
The licensee stated that the area is provided with an ionization
smoke detection system which alarms at a local panel and at the main
fire alarm panel in the CR. The licensee also stated that a fire in the
area that could potentially impact any cables of concern would likely
involve cable insulation resulting from an electrical fault or a lube
oil fire resulting from a pump and/or motor failure and that
combustibles in this area consist predominantly of IEEE 383 qualified
cable insulation or cable that has been tested and found to have
similar fire resistive characteristics. The licensee further stated
that since there is a minimal amount of Class A combustibles in this
fire area, there is little chance of a fire occurring which could act
as a pilot ignition source for the cable insulation and that while lube
oil could also serve as a pilot ignition source for cable insulation,
the small quantities of lube oil would result in a low intensity fire
and based on the elevated ignition temperature of the lube oil and the
low probability of a pump and/or motor assembly failure with subsequent
ignition of the entire quantity of lube oil, it is unlikely that a lube
oil fire from a pump and/or motor failure would serve as an ignition
source for IEEE 383 qualified cable insulation. The licensee further
stated that in the event of a fire in this area, it would be rapidly
detected in its incipient stage by the installed smoke detection
system, which will aid in providing rapid response by the Fire Brigade.
3.4.3 Preservation of Safe Shutdown Capability
The licensee stated that a fire in the area that could potentially
impact any cables of concern would likely involve cable insulation
resulting from an electrical fault or a lube oil fire resulting from a
pump and/or motor failure, that some Shutdown Cooling System components
would be affected, that Hot Standby equipment will not be affected, and
that plant shutdown to Hot Standby can be accomplished using an AOP.
3.4.4 OMAs Credited for a Fire in This Area
3.4.4.1 AFW and Charging System Flow
3.4.4.1.1 OMAs 1 and 10--Open Valve 2-CH-192 and Operate Valve 2-MS-
190A
The licensee stated that for a fire in fire area R-6, two OMAs are
identified, the first OMA (OMA 10) which is to open 2-MS-190A (ADV) and
the second OMA (OMA 1) which is to open 2-CH-192. The licensee also
stated that both OMAs are needed to compensate for a postulated loss of
IA and that neither valve will experience cable damage due to a fire in
fire area R-6. The licensee further stated that the ADVs are utilized
after AFW flow is established, that AFW is not fire impacted, is
required to be established within 45 minutes, and that prior to this,
RCS decay heat removal is provided by steaming through the MSSVs which
is also acceptable after AFW flow is established. Utilizing the ADVs,
with 2-MS-190A credited for a fire in fire area R-6, is required for
maintaining the plant in Hot Standby and initiating the transition to
Cold Shutdown. The licensee further stated that PEO-2 will remain with
the ADV to modulate steam flow per direction from the CR and that PEO-1
will complete the second OMA by opening 2-CH-192 to establish the RWST
as the source of water to the RCS and that 2-CH-192 is an air operated
valve which may have failed closed due to a loss of IA. The licensee
further stated that the valve has a safety-related air accumulator
which supplies sufficient air to stroke open the valve and maintain it
open for three hours and that after the air accumulator is exhausted,
the valve will fail closed. The licensee further stated that the
required OMA establishes/maintains RWST flow to the charging system and
that the BASTs have a minimum level specified in the TRM which ensures
charging flow for more than 72 minutes, at which time charging pump
suction is shifted to the RWST and that
[[Page 43392]]
calculations indicate that the Charging system must be restored within
three hours, and therefore, the accumulator and the minimum TRM BAST
level requirement require the OMA to locally open 2-CH-192 be
accomplished within three hours (prior to the accumulator being
exhausted).
3.4.4.2 OMA Timing
AFW flow is established within the required 45 minute time period
and should IA be lost, the OMA to continue decay heat removal can be
conducted beginning 17 minutes after AFW flow is established. The OMA
to establish Charging system flow from the RWST prior to BAST depletion
can be completed in 32 minutes which provides a 40 minute margin since
the required completion time is 72 minutes.
3.4.5 Conclusion
Given the limited amount of combustible materials and ignition
sources and installed detection, it is unlikely that a fire would occur
and go undetected or unsuppressed by the personnel, and damage the safe
shutdown equipment. The low likelihood of damage to safe shutdown
equipment due to a fire in this area, combined with the ability of the
OMAs to manipulate the plant in the event of a fire that damages safe
shutdown equipment and to be completed with more than 30 minutes of
margin, provides adequate assurance that safe shutdown capability is
maintained.
3.5 Fire Area R-7, ``A'' Diesel Generator Room
3.5.1 Fire Prevention
The licensee stated that the area has high combustible loading that
includes diesel fuel and small amounts of lube oil and that potential
ignition sources include motors, mechanical failure, and hot surfaces.
3.5.2 Detection, Control, and Extinguishment
The licensee stated that the area is provided with automatic pre-
action sprinkler protection to provide automatic suppression in/around
the diesel generator as well as to provide cooling to the structural
steel overhead and that the deluge valve for this system is opened by
the installed heat detection system. The licensee also stated that the
detection system alarms at the main fire alarm panel in the CR while
the pre-action sprinkler system alarms at a local panel and at the main
fire alarm panel in the CR.
The licensee stated that a fire in the area that could potentially
impact any cables of concern would likely involve diesel fuel oil and/
or lube oil resulting from a mechanical failure of the diesel generator
or cable insulation resulting from an electrical fault and that
combustibles in this area consist predominantly of IEEE 383 qualified
cable insulation or cable that has been tested and found to have
similar fire resistive characteristics. The licensee also stated that
since there is a minimal amount of Class A combustibles in this area,
there is little chance of a fire involving Class A combustibles
occurring which could act as a pilot ignition source for the cable
insulation and that while a fuel oil or lube oil fire could serve as a
pilot ignition source to the cabling, it is expected that a fire
involving Class B combustibles (flammable/combustible liquids) would be
rapidly detected by the installed heat detection system and be
suppressed by the installed suppression system and/or manual
firefighting. The licensee further stated that the heat detection
system would also aid in providing prompt Fire Brigade response were a
fire to occur in this area.
3.5.3 Preservation of Safe Shutdown Capability
The licensee stated that the components of concern for the area are
valves 2-CH-192, 2-CH-508, and 2-CH-509 and that the loss of the EDG
results in the loss of the Facility Z1 emergency power supply which
results in the loss of power to the battery charger supplying the
battery for valve 2-CH-192. The licensee also stated that the loss of
the Facility Z1 emergency power causes the loss of power to valves 2-
CH-508 and 2-CH-509 and that a fire could also cause the failure of IA
which would impact valves 2-CH-192 and 2-MS-190B.
The licensee stated that a fire in the area will affect all
Facility Z1 shutdown components, that Facility Z2 is used to achieve
and maintain Hot Standby, and that plant shutdown to Hot Standby can be
accomplished using an AOP.
3.5.4 OMAs Credited for a Fire in This Area
3.5.4.1 AFW and Charging System Flow
3.5.4.1.1 OMA 11--Control Valve 2-MS-190B at Panel C10 or Local Manual
Operation
The licensee stated that for a fire in the area, OMAs are required
to provide decay heat removal and restore Charging system flow to the
RCS, that AFW flow must be established to the credited SG within 45
minutes, and that the required AFW flow path utilizes the TDAFW pump
which is not fire impacted. The licensee also stated that once AFW flow
is established from the CR, operation of an ADV (2-MS-190B) (OMA 11) is
the method of removing decay heat to maintain the plant in Hot Standby
and for initiating the transition to Cold Shutdown and that prior to
AFW initiation, the plant is placed in the Hot Standby condition by
steaming through the MSSVs. The licensee further stated that there is
no cable damage from a fire in the area to the required ADV (2-MS-
190B), however, the fire may cause a loss of IA which is required to
operate the ADVs to support decay heat removal. The licensee further
stated that upon a loss of IA, the ADV will fail closed and this ``fail
to closed'' design prevents excessive RCS cooldown prior to AFW start,
and therefore, in the event of a loss of IA, Operators will establish
local manual control of 2-MS-190B after AFW is established and that
PEO-1 will remain with the ADV to modulate steam flow per direction
from the CR.
3.5.4.1.2 OMAs 4, 5, and 1--Open Valve 2-CH-508, Open Valve 2-CH-509,
and Open Valve 2-CH-192
The licensee stated that for a fire in the area the Charging system
has OMAs identified and that the BASTs gravity feed valves, 2-CH-508
(OMA 4) and 2-CH-509 (OMA 5), may fail as is (closed) due to a loss of
power supply. The licensee also stated that an OMA is in place to
locally open the valves as part of restoring the Charging system and
that once these valves are opened, the CR can establish charging flow
within 2-3 minutes. The licensee further stated that establishing pump
suction from the BASTs and restoring charging is required within three
hours of reactor shutdown/loss of charging and charging is re-
established within 24 minutes (21 minutes to open BASTs valves and 3
minutes to establish charging flow in the CR) which provides a 156
minute margin. The licensee further stated that after the BASTs have
reached the 10 percent level, Operators switch the charging suction
flow path to the RWST and the 2-CH-192 (OMA 1) valve is required to be
open to accomplish the switch over. The licensee further stated that
evaluations conclude that the BASTs will last a minimum of 72 minutes
after charging is re-established. The licensee stated that valve 2-CH-
192 fails closed in the event of a loss of its power supply and/or IA,
but valve 2-CH-192 will remain operable using its backup air source
until it and/or the Facility Z1 battery is depleted and that the backup
air source is capable of opening the valve and maintaining it open for
three hours. The licensee further stated that battery depletion will
[[Page 43393]]
not occur prior to exhausting the backup air source and that the OMA is
not required prior to this time.
3.5.4.2 OMA Timing
AFW flow is established from the CR within the required 45 minute
time period and should IA be lost, the OMA to continue decay heat
removal can be conducted beginning 17 minutes after AFW flow is
established. The OMA to establish Charging system flow from the BASTs
can be completed in 24 minutes which provides a 156 minute margin since
the required completion time is 180 minutes. The OMA to establish
Charging system flow from the RWST prior to BAST depletion can be
completed in 32 minutes which provides a 40 minute margin since the
required completion time is 72 minutes.
3.5.5 Conclusion
Although a fuel oil or lube oil fire could serve as a pilot
ignition source to cabling, it is expected that such a fire would be
detected by the installed heat detection and controlled by the
suppression system with additional suppression provided by manual
firefighting, therefore, it is unlikely that a fire would occur and go
undetected or unsuppressed and damage safe shutdown equipment. The low
likelihood of damage to safe shutdown equipment due to a fire in this
area, combined with the ability of the OMAs to manipulate the plant in
the event of a fire that damages safe shutdown equipment and to be
completed with more than 30 minutes of margin, provides adequate
assurance that safe shutdown capability is maintained.
3.6 Fire Area R-8, ``B'' Diesel Generator Room
3.6.1 Fire Prevention
The licensee stated that the area has high combustible loading that
includes diesel fuel oil, small amounts of lube oil, and negligible
amounts of cable insulation and that potential ignition sources include
electrical faults, motors, mechanical failure and hot surfaces.
3.6.2 Detection, Control, and Extinguishment
The licensee stated that this area is provided with automatic pre-
action sprinkler protection to provide automatic suppression in/around
the diesel generator as well as to provide cooling to the structural
steel overhead and that the deluge valve for this system is opened by
the installed heat detection system. The licensee also stated that the
detection system alarms at the main fire alarm panel in the CR while
the pre-action sprinkler system alarms at a local panel and at the main
fire alarm panel in the CR. The licensee stated that a fire in the area
that could potentially impact any cables of concern would likely
involve diesel fuel oil and/or lube oil resulting from a mechanical
failure of the diesel generator or cable insulation resulting from an
electrical fault and that combustibles in this area consist
predominantly of IEEE 383 qualified cable insulation or cable that has
been tested and found to have similar fire resistive characteristics.
The licensee also stated that since there is a minimal amount of Class
A combustibles in this area, there is little chance of a fire involving
Class A combustibles occurring which could act as a pilot ignition
source for the cable insulation and that while a fuel oil or lube oil
fire could serve as a pilot ignition source to the cabling, it is
expected that a fire involving Class B flammable/combustible liquids
would be rapidly detected by the installed heat detection system and be
suppressed by the installed suppression system and/or manual
firefighting. The licensee further stated that the heat detection
system would also aid in providing prompt Fire Brigade response were a
fire to occur in this area.
3.6.3 Preservation of Safe Shutdown Capability
The licensee stated that the OMAs associated with a fire in the
area are related to failure of the ``B'' EDG resulting in the loss of
power to breakers 24D, 22F and MCC B61, and the battery charger
resulting in the depletion of the ``B'' battery and that a fire in this
area could also cause the failure of IA.
The licensee stated that a fire in the area will affect all
Facility Z2 shutdown components, that Facility Z1 is used to achieve
and maintain Hot Standby, and that plant shutdown to Hot Standby can be
accomplished by using an AOP.
3.6.4 OMAs Credited for a Fire in This Area
3.6.4.1 AFW and Charging System Flow
3.6.4.1.1 OMAs 10 and 1--Operate Valve 2-MS-190A and Open Valve 2-CH-
192
The licensee stated that for a fire in the area, two OMAs are
identified, the first OMA (OMA 10) is to open 2-MS-190A (ADV) and the
second OMA (OMA 1) is to open 2-CH-192. The licensee also stated that
both OMAs are required to compensate for a postulated loss of IA and
that neither valve will experience cable damage due to a fire in the
area. The licensee further stated that the ADVs are utilized after AFW
flow is established, that AFW is not fire impacted, is required to be
established within 45 minutes and that prior to this, RCS decay heat
removal is provided by steaming through the MSSVs which is also
acceptable after AFW flow is established. The licensee further stated
that utilizing the ADVs, with 2-MS-190A credited for the fire in the
area, is required for maintaining the plant in Hot Standby and
initiating the transition to Cold Shutdown, that PEO-1 will remain with
the ADV to modulate steam flow per direction from the CR and that PEO-2
will complete the second OMA by opening 2-CH-192 to establish the RWST
as the source of water to the RCS. The licensee further stated that 2-
CH-192 is an AOV which may have failed closed due to a loss of IA, that
the valve has a safety-related air accumulator which supplies
sufficient air to stroke open the valve and maintain it open for three
hours and that after the air accumulator is exhausted, the valve will
fail closed. The licensee further stated that the required OMA
establishes/maintains RWST flow to the Charging system and the BASTs
have a minimum level specified in the TRM which ensures Charging flow
for more than 72 minutes, at which time Charging Pump suction is
shifted to the RWST. The licensee further stated that calculations
indicate that the Charging system is to be restored within three hours,
therefore, the accumulator and the minimum TRM BAST level requirement
require the OMA to locally open 2-CH-192 within three hours (prior to
the accumulator being exhausted).
3.6.4.1.2 OMA 20--Obtain CST Level at Local Level Indicating Switch
LIS-5489A
In their letter dated February 29, 2012 the licensee added OMA 20
to the exemption request for fire area R-8. The licensee stated that a
fire in the area could cause a loss of the ``B'' EDG resulting in the
depletion of the ``B'' battery after 480 minutes causing a loss of
level transmitter LT-5282 (CST Level) which will necessitate obtaining
level readings locally at the tank using level indicator LIS-5489 (OMA
20). The licensee also stated that the route to the CST is illuminated
by emergency lighting units (ELUs), that checking the level of the CST
supports AFW system operation and checking the level is not a short-
term requirement as there is sufficient inventory in the CST to provide
over 10 hours of water flow to the AFW system. The licensee further
stated that if necessary, after the CST is depleted, Operators can
switch over to the fire water system and maintain flow to the AFW
system.
[[Page 43394]]
3.6.4.2 OMA Timing
AFW flow is established from the CR within the required 45 minute
time period and should IA be lost, the OMA to continue decay heat
removal can be conducted beginning 17 minutes after AFW flow is
established. The OMA to check CST level can be completed in 6 minutes
and is a long term action as the CST provides over 10 hours of
inventory to AFW. The OMA to establish Charging system flow from the
RWST prior to BAST depletion can be completed in 32 minutes which
provides a 40 minute margin since the required completion time is 72
minutes.
3.6.5 Conclusion
Although a fuel oil or lube oil fire could serve as a pilot
ignition source to cabling, it is expected that such a fire would be
detected and suppressed by the installed heat detection and suppression
system with additional suppression provided by manual firefighting,
therefore, it is unlikely that a fire would occur and go undetected or
unsuppressed and damage safe shutdown equipment. The low likelihood of
damage to safe shutdown equipment due to a fire in this area, combined
with the ability of the OMAs to manipulate the plant in the event of a
fire that damages safe shutdown equipment and to be completed with more
than 30 minutes of margin, provides adequate assurance that safe
shutdown capability is maintained.
3.7 Fire Area R-9, ``A'' East DC Equipment Room
3.7.1 Fire Prevention
The licensee stated that the area has low combustible loading that
predominantly consists of cable insulation and that potential ignition
sources include electrical faults.
3.7.2 Detection, Control, and Extinguishment
The licensee stated that the area is provided with a cross-zoned
ionization and photoelectric smoke detection system that activates a
total flooding Halon 1301 fire suppression system and that the Halon
1301 suppression system has manual release stations at each doorway and
an abort switch located at the doorway to the east CR/cable vault
stairway. The licensee also stated that this system alarms locally at
the Halon control panel and at the main fire alarm panel in the CR. The
licensee further stated that duct smoke detection is provided between
this area, the ``B'' (West) DC Equipment Room (FHA Zone A-21), and the
auxiliary building cable vault (FHA Zone A-24) and that this system
alarms at a local panel and at the main fire alarm panel in the CR. The
licensee further stated that a fire in the area that could potentially
impact any cables of concern would likely involve cable insulation
resulting from an electrical fault or failure of a bus or electrical
panel located in the room and that combustibles in this area consist
predominantly of IEEE 383 qualified cable insulation or cable that has
been tested and found to have similar fire resistive characteristics.
The licensee further stated that since there is a minimal amount of
Class A combustibles in this area, there is little chance of a fire
occurring, outside of a bus/electrical panel failure, which could act
as a pilot ignition source for the cable insulation and that a bus/
electrical panel failure normally results in a high intensity fire that
lasts for a short duration, which makes it unlikely that it will cause
sustained combustion of IEEE 383 qualified cables. The licensee further
stated that in the unlikely event of a fire in this area, it would be
rapidly detected by the cross-zoned ionization and photoelectric smoke
detection system and subsequently extinguished by the total flooding
Halon 1301 suppression system and that the smoke detection system would
also aid in providing prompt Fire Brigade response.
3.7.3 Preservation of Safe Shutdown Capability
The licensee stated that the OMAs associated with a fire in the
area are related to loss of power to the ``A'' DC buses (such as DV10)
and that cables for valves 2-CH-192, 2-CH-508, and 2-CH-509 do not pass
through this room.
The licensee stated that a fire in the area will affect all
Facility Z1 shutdown components, that Facility Z2 is used to achieve
and maintain Hot Standby, and that plant shutdown to Hot Standby can be
accomplished using an AOP.
3.7.4 OMAs Credited for a Fire in This Area
In their letter dated February 29, 2012 the licensee deleted OMAs 1
and 11 from the exemption request for fire area R-9 since loss of IA is
no longer postulated.
3.7.4.1 AFW and Charging System Flow
3.7.4.1.1 OMAs 4 and 5.--Open Valve 2-CH-508 and Open Valve 2-CH-509
The licensee stated that for a fire in fire area R-9, the Charging
system has OMAs identified and that the BASTs gravity feed valves, 2-
CH-508 (OMA 4) and 2-CH-509 (OMA 5), may fail as is (closed) due to a
loss of power supply. The licensee also stated that an OMA is in place
to locally open the valves as part of restoring the Charging system and
that once these valves are opened, the CR can establish charging flow
within 2-3 minutes. The licensee further stated that establishing
charging pump suction from the BASTs and restoring charging is required
within three hours of reactor shutdown/loss of charging and that
Charging is re-established within 24 minutes (21 minutes to open the
BASTs valves and 3 minutes to establish charging flow in the CR) which
provides a 156 minute margin.
3.7.4.2 OMA Timing
AFW flow is established from the CR within the required 45 minute
time period. The OMA to establish Charging system flow from the BASTs
can be completed in 24 minutes which provides a 156 minute margin since
the required completion time is 180 minutes.
3.7.5 Conclusion
Given the limited amount of combustible materials and ignition
sources and installed detection and suppression, it is unlikely that a
fire would occur and go undetected or unsuppressed by the personnel,
and damage the safe shutdown equipment. The low likelihood of damage to
safe shutdown equipment due to a fire in this area, combined with the
ability of the OMAs to manipulate the plant in the event of a fire that
damages safe shutdown equipment and to be completed with more than 30
minutes of margin, provides adequate assurance that safe shutdown
capability is maintained.
3.8 Fire Area R-10, ``B'' West DC Equipment Room
3.8.1 Fire Prevention
The licensee stated that the area has low combustible loading that
predominantly consists of cable insulation and that potential ignition
sources include electrical faults.
3.8.2 Detection, Control, and Extinguishment
The licensee stated that the area is provided with a cross-zoned
ionization and photoelectric smoke detection system that activates a
total flooding Halon 1301 fire suppression system and that the Halon
1301 suppression system has manual release stations at each doorway and
an abort switch located at the doorway to the ``A'' (East) DC equipment
room (FHA Zone A-20). The licensee also stated that this system alarms
locally on the halon control panel and at the main fire alarm panel
[[Page 43395]]
in the CR. The licensee further stated that duct smoke detection is
provided between this fire area, the ``A'' (East) DC Equipment Room
(FHA Zone A-20), and the AB cable vault (FHA Zone A-24) and that this
system alarms at a local panel and at the main fire alarm panel in the
CR. The licensee further stated that a fire in the area that could
potentially impact any cables of concern would likely involve cable
insulation resulting from an electrical fault or failure of a bus or
electrical panel located in the room and that combustibles in this area
consist predominantly of IEEE 383 qualified cable insulation or cable
that has been tested and found to have similar fire resistive
characteristics. The licensee further stated that since there is a
minimal amount of Class A combustibles in this area, there is little
chance of a fire occurring, outside of a bus/electrical panel failure,
which could act as a pilot ignition source for the cable insulation and
that a bus/electrical panel failure normally results in a high
intensity fire that lasts for a short duration, which makes it unlikely
that it will cause sustained combustion of IEEE 383 qualified cables.
The licensee further stated that in the unlikely event of a fire in
this area, it would be rapidly detected by the cross-zoned ionization
and photoelectric smoke detection smoke detection system and
subsequently extinguished by the total flooding Halon 1301 suppression
system installed in this area. The smoke detection system would also
aid in providing prompt Fire Brigade response.
3.8.3 Preservation of Safe Shutdown Capability
The licensee stated that the OMAs associated with a fire in the
area are related to loss of power to the ``B'' AC vital power panels
(such as VA20) and that cables for level transmitters LT-206, LT-208
and LT-5282 do not pass through this room.
The licensee stated that a fire in the area will affect all
Facility Z2 shutdown components, that Facility Z1 is used to achieve
and maintain Hot Standby, and that plant shutdown to Hot Standby can be
accomplished using an AOP.
3.8.4 OMAs Credited for a Fire in This Area
In their letter dated February 29, 2012 the licensee deleted OMA 1
and 10 from the exemption request for fire area R-10 since loss of IA
is no longer postulated.
3.8.4.1 AFW and Charging System Flow
3.8.4.1.1 OMA 20--Obtain CST Level at Local Level Indicating Switch
LIS-5489A
The licensee stated that a fire in area may cause cable damage to
level transmitter LT-5282 (CST Level) which will necessitate obtaining
level readings locally at the tank using level indicator LIS-5489 (OMA
20). The licensee also stated that the route to the CST is illuminated
by ELUs, that checking the level of the CST supports AFW system
operation and checking the level is not a short-term requirement as
there is sufficient inventory in the CST to provide over 10 hours of
water flow to the AFW system. The licensee further stated that if
necessary, after the CST is depleted, Operators can switch over to the
fire water system and maintain flow to the AFW system.
3.8.4.1.2 OMAs 18 and 19--Obtain BAST Level at Local Level Indicator
LI-206A and Obtain BAST Level at Local Level Indicator LI-208A
The licensee stated that for a fire in the area, the Charging
system has OMAs identified and that fire damage to cables may render
level transmitters LT-206 and LT-208 (BAST Level) inoperable from the
CR which would necessitate BAST level indication being obtained locally
via level indicators LI-206A (OMA 18) and LI-206B (OMA 19). The
licensee also stated that the TRM requires a minimum level be
maintained in the BASTs and that maintaining this level provides a
minimum of 72 minutes of charging flow to the RCS after charging is re-
established and that calculations indicate that charging must be
restored within three hours of a reactor trip.
3.8.4.2 OMA Timing
AFW flow is established from the CR within the required 45 minute
time period. The OMA to check CST level can be completed in 6 minutes
and is a long term action as the CST provides over 10 hours of
inventory to AFW. The OMAs to check BAST level can be completed in 12
minutes which provides a 168 minute margin since the required
completion time is 180 minutes.
3.8.5 Conclusion
Given the limited amount of combustible materials and ignition
sources and installed detection and suppression, it is unlikely that a
fire would occur and go undetected or unsuppressed by the personnel,
and damage the safe shutdown equipment. The low likelihood of damage to
safe shutdown equipment due to a fire in this area, combined with the
ability of the OMAs to manipulate the plant in the event of a fire that
damages safe shutdown equipment and to be completed with more than 30
minutes of margin, provides adequate assurance that safe shutdown
capability is maintained.
3.9 Fire Area R-12, Steam Driven Auxiliary Feedwater Pump Pit
3.9.1 Fire Prevention
The licensee stated that the area has low combustible loading that
includes lube oil only, that there is no cable insulation or Class A
combustibles located in the area, and that potential ignition sources
include electrical faults or the over-heating of a pump bearing.
3.9.2 Detection, Control, and Extinguishment
The licensee stated that the area is provided with an ionization
smoke detection system which alarms at a local panel and at the main
fire alarm panel in the CR. The licensee stated that a fire in the
TDAFW Pump Pit that could potentially impact any cables of concern
would likely involve a lube oil fire resulting from an auxiliary
feedwater pump failure and that lube oil found within the steam driven
AFW pump is the only contributing factor to the combustible loading of
this area. The licensee also stated that the lube oil is completely
enclosed within the pump housing, which would help in preventing
ignition of the oil from an external ignition source and that there are
no external ignition sources for the lube oil in this room. The
licensee further stated that restrictive access to this pump room
limits the amount of transient combustibles and ignition sources in
this room and in the event of a fire in this room, the low combustible
loading would result in a low intensity fire which would be rapidly
detected in its incipient stage by the installed smoke detection
system, which will aid in providing rapid response by the Fire Brigade.
3.9.3 Preservation of Safe Shutdown Capability
The licensee stated that a fire in the area will affect only the
TDAFW pump and its steam supply components, that no other Hot Standby
equipment will be affected and the MDAFW pumps may be used to feed the
SGs. The licensee also stated that plant shutdown to Hot Standby can be
accomplished using existing shutdown procedures.
[[Page 43396]]
3.9.4 OMAs Credited for a Fire in This Area
3.9.4.1 AFW and Charging System Flow
3.9.4.1.1 OMA 10--Operate Valve 2-MS-190A and Open Valve 2-CH-192
The licensee stated that for a fire in the area, two OMAs are
identified, the first is to open 2-MS-190A (ADV) (OMA 10) and the
second is to open 2-CH-192 (OMA 1). The licensee also stated that both
OMAs are required to compensate for a postulated loss of IA, that
neither valve will experience cable damage due to a fire in the area,
and that the ADVs are utilized after AFW flow is established. The
licensee further stated that AFW flow is required to be established
within 45 minutes and that prior to this, RCS decay heat removal is
provided by steaming through the MSSVs which is also acceptable after
AFW flow is established. The licensee further stated that utilizing the
ADVs, with 2-MS-190A credited for the fire in the area, is required for
maintaining the plant in Hot Standby and the transition to Cold
Shutdown, and that PEO-1 will remain with the ADV to modulate steam
flow per direction from the CR. The licensee further stated that PEO-2
will complete the second OMA by opening 2-CH-192 to establish the RWST
as the source of water to the RCS. The licensee stated that 2-CH-192 is
an AOV which may have failed closed due to a loss of IA and that the
valve has a safety-related air accumulator which supplies sufficient
air to stroke open the valve and maintain it open for three hours.
After the air accumulator is exhausted, the valve will fail closed. The
licensee further stated that the required OMA establishes/maintains
RWST flow to the Charging system and that the BASTs have a minimum
level specified in the TRM which ensures Charging flow for more than 72
minutes, at which time Charging Pump suction is shifted to the RWST.
The licensee further stated that calculations indicate that the
Charging system must be restored within 3 hours, therefore, the
accumulator capacity and the minimum TRM BAST level requirements
require that this OMA be accomplished within three hours (prior to the
accumulator being exhausted).
3.9.4.2 OMA Timing
AFW flow is established from the CR within the required 45 minute
time period and should IA be lost, the OMA to continue decay heat
removal can be conducted beginning 17 minutes after AFW flow is
established. The OMA to establish Charging system flow from the RWST
prior to BAST depletion can be completed in 32 minutes which provides a
40 minute margin since the required completion time is 72 minutes.
3.9.5 Conclusion
Given the limited amount of combustible materials and ignition
sources and installed detection, it is unlikely that a fire would occur
and go undetected or unsuppressed by the personnel, and damage the safe
shutdown equipment. The low likelihood of damage to safe shutdown
equipment due to a fire in this area, combined with the ability of the
OMAs to manipulate the plant in the event of a fire that damages safe
shutdown equipment and to be completed with more than 30 minutes of
margin, provides adequate assurance that safe shutdown capability is
maintained.
3.10 Fire Area R-13, West 480 V Load Center Room
3.10.1 Fire Prevention
The licensee stated that the area has low combustible loading that
predominantly consists of cable insulation and that potential ignition
sources include electrical faults.
3.10.2 Detection, Control, and Extinguishment
The licensee stated that the area is provided with ionization smoke
detection that alarms at the main fire alarm panel in the CR. The
licensee also stated that a fire in the area that could potentially
impact any cables of concern would likely involve cable insulation
resulting from an electrical fault or a bus failure and that
combustibles in the area consist predominantly of IEEE 383 qualified
cable insulation or cable that has been tested and found to have
similar fire resistive characteristics. The licensee further stated
that since there is a minimal amount of Class A combustibles in this
area, there is little chance of a fire occurring, outside of a bus
failure, which could act as a pilot ignition source for the cable
insulation. A bus failure normally results in a high intensity fire
that lasts for a short duration, which makes it unlikely that it will
cause sustained combustion of IEEE 383 qualified cables. The licensee
further stated that in the unlikely event of a fire, it would be
rapidly detected by the ionization smoke detection system installed in
the area and that the smoke detection system will aid in providing
prompt Fire Brigade response.
3.10.3 Preservation of Safe Shutdown Capability
The licensee stated that the components of concern for the area are
for valves 2-CH-192, 2-CH-508, 2-CH-509, 2-FW-43B and 2-MS-190B,
breaker A406, H21 (TDAFW speed control circuit), level transmitter LT-
5282, P18C (``C'' charging pump), SV-4188 (TDAFW steam supply valve)
and breaker DV2021.
The licensee stated that a fire in the area will affect Facility Z1
safe shutdown equipment, that the ``A'' EDG will be unavailable due to
a loss of the Facility Z1 power supply for the diesel room ventilation
fan F38A, that Facility Z2 is used to achieve and maintain Hot Standby,
and that plant shutdown to Hot Standby can be accomplished using an
AOP.
3.10.4 OMAs Credited for a Fire in This Area
In their letter dated February 29, 2012, the licensee deleted OMAs
1, 9, and 11, from the exemption request for fire area R-13 since loss
of IA is no longer postulated.
3.10.4.1 AFW Flow
3.10.4.1.1 OMAs 22 and 17--Operate Supply Valve SV-4188 From Panel C10
and Operate Turbine Driven AFW Pump Speed Control Circuit H-21 From
Panel C10
The licensee stated that for a fire in the area, OMAs are required
to provide decay heat removal and restore Charging system flow to the
RCS and that establishing AFW flow to the credited SG is required
within 45 minutes. The licensee stated that for a fire in the area, the
required AFW flow path utilizes the TDAFW pump and that due to fire
induced cable damage, AFW turbine steam supply valve (SV-4188) (OMA
22), and TDAFW turbine speed control (H21) (OMA 17) may not be
available from the CR. The licensee further stated that the cable
damage can be isolated and the TDAFW pump can be operated from the Fire
Shutdown Panel (C-10) located in fire area R-2 and that an OMA is
necessary to isolate the damaged cables and operate the TDAFW turbine
speed control to maintain level in the SG. The licensee stated that in
the case of 2-FW-43B, cable damage could result in spurious operation
and that isolation of the affected cables and control of the valve can
be accomplished at the C-10 panel, and that control of SG water level
can be maintained using the speed control function of the TDAFW pump.
The licensee further stated that the timeframe to establish control of
TDAFW at the C-10 panel is 45 minutes and that after Reactor Operator 1
(RO-1) has established control of TDAFW pump speed at the C-10 panel (8
minutes), it will take an additional 2
[[Page 43397]]
minutes to establish AFW flow which results in a total time to
establish AFW flow of 10 minutes, leaving a 35 minute margin.
3.10.4.1.2 OMA 20--Obtain CST Level at Local Level Indicating Switch
LIS-5489A
The licensee stated that valves 2-MS-190B and 2-FW-43B can be
operated from the C-10 panel and that the OMA for local or C-10
operation of 2-MS-190B is not required until after AFW flow is
established and that PEO-1 will remain with the ADV to modulate steam
flow per direction from the CR. The licensee further stated that the
final decay heat removal function is to monitor CST level from either
the C-10 panel (LT-5282) or locally at the CST (LIS-5489) (OMA 20) and
that checking the level is not a short-term requirement because there
is sufficient inventory in the CST to provide over 10 hours of water
flow to the AFW system. The licensee further stated that a spurious
start of the TDAFW coupled with 2-FW-43B failing open should not result
in a SG overfill and that the nominal water level in the SG is
maintained between 60-75% as indicated on the Narrow Range (NR) level
instruments (i.e. the normal operating band). The licensee further
stated that from the top of the normal operating band, more than 8000
gallons of water can be added before reaching 100 percent on the NR
level instruments and allotting 8 minutes to establish operations from
the C-10 panel and assuming all the flow from the TDAFW is filling one
SG, approximately 4800 gallons can be added before regaining level
control. The licensee further stated that there is also an additional
14,000 gallons of margin available before the SG would overfill (i.e.
from 100 percent NR to the Main Steam nozzle).
3.10.4.2 Charging System Flow
3.10.4.2.1 OMAs 4, 5, 16, 21, and 24--Open Valve 2-CH-508, Open Valve
2-CH-509, Pull Control Power Fuses for Breaker A406 and Ensure Breaker
Is Open, Operate Pump P18C From Panel C10, and Locally Close Breaker
DV2021
The licensee stated that for a fire in the area, the Charging
system has OMAs identified. The BASTs gravity feed valves, 2-CH-508 and
2-CH-509, may fail as is, (closed) due to cable damage and that OMAs
are (OMA 4 and 5) in place to locally open these valves as part of
restoring the Charging system. The licensee further stated that cable
damage due to fire may also cause a spurious start of the P18C Charging
Pump and that cable damage may be mitigated by isolating and operating
P18C (OMA 21) at the C-10 panel. The licensee further stated that RO-1
is at C-10 and must manipulate the controls for P18C and that
establishing pump suction from the BASTs and operating P18C is required
within 3 hours of reactor shutdown/loss of Charging. The licensee
further stated that completing the OMAs to re-establish Charging would
take 23 minutes leaving a margin of 157 minutes, which includes the
parallel actions of PEO-2 establishing control of Bus 24D (by pulling
control power fuses to circuit breaker A406 (OMA 16), ensuring A406 is
open and closing breaker DV2021 (OMA 24) and PEO-3 (by manually
aligning valves 2-CH-508 and 2-CH-509). The licensee further stated
that after the BASTs have reached the 10 percent level, Operators
switch Charging Pump suction over to the RWST and valve 2-CH-192 may
fail closed due to a loss of power supply, but it can be controlled
from the CR.
3.10.4.4 OMA Timing
The OMAs to establish AFW flow can be completed in 10 minutes which
provides a 35 minute margin since the required completion time is 45
minutes. The OMA to check CST level can be completed in 3 minutes and
is a long term action as the CST provides over 10 hours of inventory to
AFW. The OMAs to establish Charging system flow from the BASTs can be
completed in 23 minutes which provides a margin of 157 minutes since
the required completion time is 180 minutes.
3.10.5 Conclusion
Given the limited amount of combustible materials and ignition
sources and installed detection, it is unlikely that a fire would occur
and go undetected or unsuppressed by the personnel, and damage the safe
shutdown equipment. The low likelihood of damage to safe shutdown
equipment due to a fire in this area, combined with the ability of the
OMAs to manipulate the plant in the event of a fire that damages safe
shutdown equipment and to be completed with more than 30 minutes of
margin, provides adequate assurance that safe shutdown capability is
maintained.
3.11 Fire Area R-14, Lower 6.9 and 4.16 kV Switchgear Room, East Cable
Vault
3.11.1 Fire Prevention
The licensee stated that the areas have low combustible loading
that predominantly consists of cable insulation and Thermo-Lag fire
resistant wrap, and that potential ignition sources include electrical
faults.
3.11.2 Detection, Control, and Extinguishment
The licensee stated that the Lower 6.9 and 4.16 kV Switchgear Room
contains ionization smoke detectors located directly over each
switchgear cabinet that alarm at the main fire alarm panel in the CR.
The licensee also stated that a fire in the Lower 6.9 and 4.16 kV
Switchgear Room that could potentially impact cables of concern would
likely involve cable insulation resulting from an electrical fault in
one of the cable trays routed over Bus 24E or failure of Bus 24E
itself. Combustibles in this area consist predominantly of IEEE 383
qualified cable insulation or cable that has been tested and found to
have similar fire resistive characteristics. The licensee further
stated that since there is a minimal amount of Class A combustibles in
this area, there is little chance of a fire occurring, outside of a
switchgear failure, which could act as a pilot ignition source for the
cable insulation and that a switchgear failure normally results in a
high intensity fire that lasts for a short duration, which makes it
unlikely that it will cause sustained combustion of IEEE 383 qualified
cables. The licensee further stated that in the unlikely event of a
fire, it would be rapidly detected by the ionization smoke detection
system installed in the area and that the smoke detection system, which
consists of an ionization smoke detector located directly over each
switchgear cabinet in the area, will aid in providing prompt Fire
Brigade response.
The licensee stated that the East Cable Vault is provided with an
automatic wet-pipe sprinkler system designed to protect structural
steel and an ionization smoke detection system that alarms at the main
fire alarm panel in the CR. The licensee also stated that the vertical
cable chase that leads down the AB cable vault is protected by an
automatic deluge spray system which is actuated by a cross-zoned smoke
detection system that alarms at a local panel and at the main fire
alarm panel in the CR. The licensee further stated that a fire in the
area that could potentially impact any cables of concern would likely
involve cable insulation resulting from an electrical fault and that
combustibles in this area consist predominantly of IEEE 383 qualified
cable insulation or cable that has been tested and found to have
similar fire resistive characteristics. The licensee further stated
that since there is a minimal amount of Class A combustibles in this
area, there is little chance of a fire
[[Page 43398]]
occurring which could act as a pilot ignition source for the cable
insulation. The licensee further stated that Thermo-Lag, while
considered combustible, is one-hour fire rated in this area and that
based on its fire resistive qualities and lack of ignition sources, a
fire involving Thermo-Lag wrap is not credible. The licensee further
stated that in the event of a fire in this area, it would be rapidly
detected in its incipient stage by the installed smoke detection
system, which will aid in providing rapid response by the Fire Brigade.
In the unlikely event the fire advanced beyond its incipient stage
(unlikely based on type of cable insulation and Fire Brigade
suppression activities), it would actuate the installed automatic wet-
pipe suppression system provided in this area which will, at a minimum,
provide reasonable assurance that a cable tray fire in this area will
be controlled and confined to the immediate area of origin.
3.11.3 Preservation of Safe Shutdown Capability
The licensee stated that a fire in the Facility Z1 Lower 4.16 kV
Switchgear Room and Cable Vault will affect all Facility Z1 shutdown
components, that Facility Z2 is used to achieve and maintain Hot
Standby, that plant shutdown to Hot Standby can be accomplished using
an AOP and that OMAs are required to provide decay heat removal and
restore Charging system flow to the RCS.
The licensee stated that the cables of concern in the East Cable
Vault are the control and indication cabling for valve 2-FW-43B. The
licensee also stated that cables for valves 2-CH-192, 2-CH-508 and 2-
CH-509 are not located in this room, however, valves 2-CH-508 and 2-CH-
509 are impacted due to the potential loss of the feed cables for bus
22E or the ``A'' EDG's control and power cables which results in the
loss of power to the valves.
3.11.4 OMAs Credited for a Fire in This Area
In their letter dated February 29, 2012, the licensee deleted OMAs
1, 9 and 11 from the exemption request for fire area R-14 since loss of
IA is no longer postulated.
The licensee stated that during verification and validation of the
AOPs, it was identified that for a fire in fire area R-14 an additional
operator might be necessary to place the plant into hot standby. The
staffing requirements for MPS2 were changed to add one licensed or non-
licensed operator over the minimum technical specification (TS)
requirement to be on duty each shift during Modes 1, 2, 3, or 4, with
this operator being designated as the Appendix R operator and is not
part of the credited five man Fire Brigade crew.
3.11.4.1 Charging System Flow
3.11.4.1.1 OMAs 4 and 5--Open Valve 2-CH-508 and Open Valve 2-CH-509
The licensee stated that the Charging system has OMAs identified in
that the BASTs gravity feed valves, 2-CH-508 and 2-CH-509, may fail as
is (closed) due to a loss of power supply and that OMAs are in place
(OMA 4 for 2-CH-508 and OMA 5 for 2-CH-509) to locally open these
valves as part of restoring the Charging system. The licensee further
stated that establishing Charging Pump suction from the BASTs is
required within 3 hours of reactor shutdown/loss of Charging and that
RO-1 and PEO-3 will perform their OMAs in parallel (see Section
3.11.4.1.2) to restore Charging. OMAs 4 and 5 are completed in 21
minutes.
3.11.4.1.2 OMAs 13, 14, 15, 23, and 24--Pull Control Power Fuses for
Breaker A408 and Ensure Breaker Is Open, Pull Control Power Fuses for
Breaker A410 and Ensure Breaker Is Open, Pull Control Power Fuses for
Breaker A411 and Ensure Breaker Is Open, Pull Control Power Fuses for
Breaker A401 and Ensure Breaker Is Closed, and Locally Close Breaker
DV2021
The licensee stated that as part of the restoration of Charging
flow to the RCS, Bus 24D must be isolated from cross-ties to Bus 24B,
Bus 24E and the RSST and that this is due to fire-induced cable damage
which may result in spurious operation/loss of control from the CR of
breakers A401, A410, A408 and A411. The OMAs associated with these
breakers are to pull the control power fuses and ensure that breakers
A410 (OMA 14), A408 (OMA 13) and A411 (OMA 15) are open and that
breaker A401 (OMA 23) is closed. The licensee also stated that once RO-
1 completes the OMAs, PEO-1 will then reset and close breaker DV2021
(OMA 24). OMAs 13, 14, 15, 23 and 24 are completed in 24 minutes, then
it will take an additional 3 minutes for the CR to establish Charging
flow for a total of 27 minutes which results in a 153 minute margin
since the required completion time is 180 minutes.
3.11.4.2 OMA Timing
The OMAs to establish Charging system flow from the BASTs can be
completed in 27 minutes which provides for a margin of 153 minutes
since the required completion time is 180 minutes.
3.11.5 Conclusion
Given the limited amount of combustible materials and ignition
sources and installed detection (Lower 6.9 and 4.16 kV Switchgear Room)
and installed detection and suppression (East Cable Vault), it is
unlikely that a fire would occur and go undetected or unsuppressed by
the personnel and damage the safe shutdown equipment. The low
likelihood of damage to safe shutdown equipment due to a fire in this
area, combined with the ability of the OMAs to manipulate the plant in
the event of a fire that damages safe shutdown equipment and to be
completed with more than 30 minutes of margin, provides adequate
assurance that safe shutdown capability is maintained.
3.12 Fire Area R-15, Containment Building
3.12.1 Fire Prevention
The licensee stated that the area has low combustible loading
including cable insulation and small amounts of lube oil and that
potential ignition sources include electrical faults, motors,
mechanical failure, and hot surfaces.
3.12.2 Detection, Control, and Extinguishment
The licensee stated that the area is provided with smoke detection
at each of the East and West Electrical Penetration Areas on the 14'-
6'' elevation and that the system alarms at a local panel and at the
main fire alarm panel in the CR. The licensee also stated that heat
detection is provided for each of the Reactor Coolant Pumps (RCPs) and
that during refueling outages, the fire protection header within
Containment is charged, with hose stations available on all elevations
with the exception of the 3'-6'' elevation. The licensee further stated
that during normal plant operation, fire protection piping within the
Containment is not charged. The licensee further stated that a fire in
the Containment that could potentially impact any cables of concern
would likely involve cable insulation resulting from an electrical
fault and that combustibles in this area consist predominantly of IEEE
383 qualified cable insulation or cable that has been tested and found
to have similar fire resistive characteristics. The licensee further
stated that during plant operation, there are negligible amounts of
Class A combustibles in this area, and therefore, there is little
chance of a fire occurring which could act as a pilot ignition source
for the cable insulation. If a cable fire does occur, it would be
rapidly detected by the smoke detection
[[Page 43399]]
system installed at the east and west electrical penetration areas on
the 14'-6'' elevation of the Containment, alerting the CR to a fire
condition in Containment. The licensee further stated that a lube oil
fire serving as a pilot ignition source to cable in the Containment is
not a realistic scenario, that lube oil in this fire area is
predominantly associated with the four RCPs and that while a failure of
one of these RCP motors and a subsequent lube oil fire could be
postulated, each of the RCP motors (located on the 14'-6'' Elevation of
Containment) is partially enclosed in reinforced concrete compartments
and the floor beneath the RCPs drains to the lowest elevation of
Containment (22'-6'' Elevation). The licensee further stated that
cabling in the Containment is routed outside of these concrete
compartments along the outer annulus of the Containment and would be
shielded from an RCP motor fire. The licensee further stated that based
on the large volume of the Containment, the heat and hot gasses
generated by an RCP motor lube oil fire would rise to the upper
elevations of the Containment away from the cable tray concentrations
located at the East and West Electrical Penetration Areas on the 14'-
6'' elevation of the Containment. If an RCP motor lube oil fire does
occur, it would be detected in its incipient stage by the installed
heat detection system that protects the RCP motors, alerting the CR to
a fire condition in Containment.
3.12.3 Preservation of Safe Shutdown Capability
The licensee stated that the cables of concern for the Containment
are the power and indication cables for valves 2-CH-517 and 2-CH-519.
The licensee stated that a fire in the Containment will affect a
significant amount of instrumentation needed to monitor plant
parameters and that a review of all instrument cables inside the
Containment indicates that compliance with separation criteria was
achieved with the exception of the Pressurizer cubicle. The separation
issues inside Containment have been evaluated as follows:
1. Separation criteria were evaluated for the Pressurizer cubicle
to address instruments LT-11OX, LT-1 10Y, PT-102A, and PT-102B
(instruments located on Racks C140 and C211 in the NE quadrant of
containment) and instruments PT-103 and PT-103-1.
2. Separation criteria were evaluated for the remainder of the
instruments required for safe shutdown (RCS temperature, SG level and
pressure, core exit thermocouples, nuclear instruments (NIs),
containment temperature) and the sensing lines for the pressurizer
level and pressurizer pressure instruments.
The licensee stated that plant shutdown to Hot Standby can be
accomplished using an AOP and that for a fire in the area, OMAs are
required to provide decay heat removal and restore Charging system flow
to the RCS.
3.12.4 OMAs Credited for a Fire in This Area
3.12.4.1 AFW Flow
3.12.4.1.1 OMAs 10 and 11--Operate Valve 2-MS-190A and Control Valve 2-
MS-190B at Panel C10 or Local Manual Operation
The licensee stated that for decay heat removal, after AFW flow is
established from the CR in the required 45 minute time period,
Operators will transfer from steaming through the MSSVs to steaming
through the ADVs and that for a fire in the area, both ADVs (2-MS-190A
and 2-MS-190B) are required. The licensee also stated that operators
must first determine which SG instruments are available and that if SG1
instrumentation is available, then 2-MS-190A (OMA 10) ADV will be
utilized for the decay heat steam path, and if SG2 instrumentation is
available, then the 2-MS-190B (OMA 11) ADV will be utilized for the
decay heat steam path. The licensee further stated that neither ADV is
fire affected, however, the fire may cause a loss of IA which is
required to operate the ADVs to support decay heat removal. The
licensee further stated that upon a loss of IA, the ADV will fail
closed and that this ``fail to closed'' design prevents excessive RCS
cooldown prior to AFW start. In the event of a loss of IA, operators
will establish local manual control of 2-MS-190A or 2-MS-190B after AFW
flow is established. The licensee further stated that PEO-1 will remain
with the ADV to modulate steam flow per direction from the CR. OMAs 10
and 11 can begin 17 minutes after AFW is established by the CR.
3.12.4.2 Charging System Flow
3.12.4.2.1 OMAs 6 and 7--Open Breaker to Fail Valve 2-CH-517 Closed and
Open Breaker to Fail Valve 2-CH-519 Open
The licensee stated that the Charging system OMAs are for possible
spurious operation of valves 2-CH-517, 2-CH-518, and 2-CH-519, due to
fire-induced cable damage and that these valves are located in
Containment. The licensee also stated that PEO-3 opens breakers to
place the valves in their required positions and for valve 2-CH-517
(OMA 6), breaker DV2012 is opened which will fail the valve in the
closed position and that this breaker manipulation will also fail 2-CH-
519 (OMA 7) in its required open position. The licensee further stated
that valve 2-CH-518 is not required for a fire in the area, but will be
failed open (desired position) when other power circuits are isolated
and that once PEO-3 completes the OMA in 7 minutes, it takes
approximately 3 additional minutes for the CR to re-establish Charging
flow which provides a 170 minute margin.
3.12.4.2.2 OMA 1--Open Valve 2-CH-192
The licensee stated that although not fire affected, valve 2-CH-192
will failed closed after the isolation of power to Containment which
will necessitate an OMA (OMA 1) to establish the RWST as the source of
water to the RCS once the BASTs are depleted. The licensee also stated
that a minimum switch-over time of 72 minutes, after charging has been
restored, has been established based on the TRM BAST level requirements
and that calculations conclude that the Charging system must be
restored within 3 hours, therefore, the initial alignment of 2-CH-517
and 2-CH-519 will take place within 3 hours. The licensee further
stated that establishing the RWST as a flow path to the RCS is not
required until 1.2 hours after Charging is re-established.
3.12.4.3 OMA Timing
AFW flow is established from the CR within the required 45 minute
time period and should IA be lost, the OMA to continue decay heat
removal can be conducted beginning 17 minutes after AFW flow is
established. The OMAs to establish Charging system flow from the BAST
can be completed in 10 minutes which provides a margin of 170 minutes
since the required completion time is 180 minutes. The OMA to establish
Charging system flow from the RWST prior to BAST depletion can be
completed in 32 minutes which provides a 40 minute margin since the
required completion time is 72 minutes.
3.12.5 Conclusion
Given the limited amount of combustible materials, ignition
sources, installed partial detection, and separation from the RCPs, it
is unlikely that a fire would occur and go undetected or unsuppressed
by the personnel and damage the safe shutdown equipment. There is a low
likelihood of damage to safe shutdown equipment due to a fire in this
area. The ability of the OMAs to manipulate the plant in the event of a
fire that damages safe shutdown equipment, to be
[[Page 43400]]
completed with more than 30 minutes of margin, provides adequate
assurance that safe shutdown capability is maintained.
3.13 Fire Area R-17, East Electrical Penetration Area, East Main Steam
Safety Valve/Blowdown Tank Room, East Piping Penetration Area
3.13.1 Fire Prevention
The licensee stated that the East Electrical Penetration Area has
moderate combustible loading that includes cable insulation and small
amounts of plastics and that potential ignition sources include
electrical faults.
The licensee stated that the East Main Steam Safety Valve/Blowdown
Tank Room has low combustible loading that consists entirely of cable
insulation and that potential ignition sources include electrical
faults.
The licensee stated that the East Piping Penetration Area has low
combustible loading that includes Class A combustibles (e.g., rubber)
and that potential ignition sources include transient ignition sources
(e.g. hotwork).
3.13.2 Detection, Control, and Extinguishment
The licensee stated that the East Electrical Penetration Area is
provided with an ionization smoke detection system which alarms at the
main fire alarm panel in the CR. The licensee also stated that a fire
in the area that could potentially impact a cable of concern would
likely involve cable insulation resulting from an electrical fault. The
licensee stated that combustibles in this area consist predominantly of
IEEE 383 qualified cable insulation or cable that has been tested and
found to have similar fire resistive characteristics. The licensee
further stated that the cable trays in this area are predominantly
located towards the southern and eastern end of the room, while the
Class A combustibles are located predominantly towards the northern end
of the room. Based on the location of the Class A combustibles in
relation to the cable trays in this area, there is little chance of a
fire occurring which could act as a pilot ignition source for the cable
insulation. Based on the length of the east wall (55 feet), the
distance between the cable trays and the Class A combustibles is
approximately 45 feet. The licensee further stated that a failure of
motor control center (MCC) B-31B could also serve as an ignition source
and that an MCC failure normally results in a high intensity fire that
lasts for a short duration, which makes it unlikely that it will cause
sustained combustion of IEEE 383 qualified cables. In order to impact
the subject cable trays, an MCC failure would have to ignite a cable
tray located immediately above the MCC. The fire would also have to
propagate via the cable tray until it reached any cables of concern.
The licensee further stated that based on the discussion above, the
postulated fire scenario is highly unlikely. The characteristics of an
MCC failure and the fire retardant properties of IEEE 383 cabling also
make it implausible that failure of hydrogen analyzers C86 or C87 would
result in the ignition of a cable tray located several feet above the
analyzers. The heavy construction of the hydrogen analyzer cabinets
would further preclude this event. The licensee further stated that in
the event of a fire in this area, it would be rapidly detected in its
incipient stage by the installed smoke detection system, which will aid
in providing rapid response by the Fire Brigade.
The licensee stated that a fire in the East Main Steam Safety
Valve/Blowdown Tank Room that could potentially impact the cables of
concern would likely involve cable insulation resulting from an
electrical fault and that combustibles in this area consist
predominantly of IEEE 383 qualified cable insulation or cable that has
been tested and found to have similar fire resistive characteristics.
The licensee also stated that since the amount of Class A combustibles
in this fire area is negligible, there is little chance of a fire
occurring which could act as a pilot ignition source for the cable
insulation and in the unlikely event of a fire in this fire area, the
high ceiling and the large volume of this room would preclude a large
rise in temperature in the areas where the subject cable trays or
conduits are routed, reducing the likelihood that they would be damaged
by the fire.
The licensee stated that the East Piping Penetration Area is not
provided with a smoke detection system, however, due to the openings in
the ceiling of this area, the ionization smoke detection system located
at the ceiling of the east electrical penetration area (FHA Zone A-10B)
would provide supplemental coverage to detect a fire in this area. The
licensee stated that a fire in the East Piping Penetration Area that
could potentially impact any cables of concern would likely involve
Class A combustibles from a transient ignition source. Based on the
controls placed on transient combustibles and transient ignition
sources, it is unlikely a fire would occur in this area. The licensee
also stated that all hot work evolutions in the plant are procedurally
required to have a fire watch in place. Hot work fire watches are
individuals stationed in plant areas for the purpose of fire safety for
workers and welders, detecting and suppressing smoke, fire, flames, or
sparks as a result of hot work such as welding, cutting, or grinding.
If a fire starts as a result of hot work, it would be detected in its
incipient stages. The licensee further stated that since the amount of
Class A combustibles in this area is small, a fire in this room is
unlikely to occur. If a fire did occur, it would be of low intensity
and would not likely be of sufficient magnitude to impact cable routed
in conduit. The licensee further stated that the high ceiling of this
room and the fact that this area opens up to the east electrical
penetration area above (FHA Zone A-10B) would preclude a large rise in
temperature in the areas where the subject conduits are routed,
lessening the likelihood that they would be damaged by the fire.
3.13.3 Preservation of Safe Shutdown Capability
The licensee stated that OMAs associated with a fire in the East
Electrical Penetration Area are related to failure of the ``A'' EDGs
power or control cables resulting in the loss of power to buses 24C,
22E, B51 and the battery charger, which results in the depletion of the
``A'' battery and that a fire in this area could also cause the failure
of IA.
The licensee stated that the OMAs associated with a fire in the
East Main Steam Safety Valve/Blowdown Tank Room are related to failure
of IA and that cables for valves 2-CH-192 and 2-MS-190B do not enter
this room.
The licensee stated that in the event of a fire in the East
Penetration Area which could affect Facility Z1 shutdown components,
Facility Z2 is used to achieve and maintain Hot Standby and that plant
shutdown to Hot Standby can be accomplished using an AOP. The licensee
also stated that for a fire in the area, OMAs are required to provide
decay heat removal and restore charging system flow to the RCS.
3.13.4 OMAs Credited for a Fire in This Area
3.13.4.1 AFW Flow
3.13.4.1.1 OMA 11--Control Valve 2-MS-190B at Panel C10 or Local Manual
Operation
The licensee stated that establishing AFW flow to the credited SG
is required within 45 minutes and that for a fire in the area, the
required AFW flow path utilizes the TDAFW pump. The licensee
[[Page 43401]]
also stated that once AFW flow is established from the CR, operation of
the ADV (2-MS-190B) (OMA 11) is the required method for maintaining the
plant in Hot Standby and transitioning to Cold Shutdown and that prior
to AFW initiation, the plant is placed in the Hot Standby condition by
steaming through the MSSVs. The licensee further stated that a fire in
the area would not damage any cables associated with ADV (2-MS-1 90B),
however, the fire might cause a loss of IA which is required to operate
the ADVs and support decay heat removal. The licensee further stated
that upon a loss of IA, the ADV will fail closed and that this ``failed
to close'' design prevents excessive RCS cooldown prior to AFW start.
Therefore, in the event of a loss of IA, Operators will establish local
manual control of 2-MS-190B after AFW flow is established. The licensee
further stated that PEO-1 will remain with the ADV to modulate steam
flow per direction from the CR.
3.13.4.2 Charging System Flow
3.13.4.2.1 OMAs 4, 5 and 1--Open Valve 2-CH-508, Open Valve 2-CH-509,
and Open Valve 2-CH-192
The licensee stated that for a fire in the area, the Charging
system has OMAs identified as the BASTs gravity feed valves, 2-CH-508
and 2-CH-509, might fail as is (closed) due to a loss of power supply.
The licensee also stated that OMAs (OMA 4 and 5) are in place to
locally open these valves as part of restoring the Charging system and
that once these valves are opened, the CR can establish Charging flow
within 2-3 minutes. The licensee further stated that establishing
Charging Pump suction from the BASTs is required within 3 hours of
reactor shutdown/loss of charging, and Charging is therefore re-
established within 24 minutes (21 minutes to open BASTs valves and 3
minutes to establish charging flow from the CR) which provides a 156
minute margin. The licensee further stated that after the BASTs have
reached the 10 percent level, Operators switch the charging pump
suction over to the RWST and that valve 2-CH-192 will fail closed when
DV1013 is opened to mitigate spurious operation of 2-CH-518 and that an
OMA is required to open 2-CH-192 (OMA 1) once the BASTs supply to
charging is exhausted. The licensee further stated that evaluations
conclude that the BASTs will last a minimum of 72 minutes after
Charging is re-established and that the OMA is not required to be
performed prior to this time.
3.13.4.3 OMA Timing
AFW flow is established from the CR within the required 45 minute
time period and should IA be lost, the OMA to continue decay heat
removal can be conducted beginning 17 minutes after AFW flow is
established. The OMAs to establish Charging system flow from the BAST
can be completed in 24 minutes which provides a margin of 156 minutes
since the required completion time is 180 minutes. The OMA to establish
Charging system flow from the RWST prior to BAST depletion can be
completed in 32 minutes which provides a 40 minute margin since the
required completion time is 72 minutes.
3.13.5 Conclusion
Given the limited amount of combustible materials and ignition
sources, administrative controls, available margin (40 minutes), and
installed detection in the East Electrical Penetration Area, it is
unlikely that a fire would occur and go undetected or unsuppressed by
the personnel, and damage the safe shutdown equipment.
The East Piping Penetration Room has limited combustible materials
and ignition sources and lacks credible fire scenarios, but is not
provided with detection. However, due to the openings in the ceiling,
the detection located in the East Electrical Penetration Area provides
some coverage to the East Piping Penetration Room. A fire in this room,
although unlikely, would be expected to be of low intensity and not
likely to impact cable routed in conduit. In addition, the high ceiling
and ceiling openings to the East Electrical Penetration Area would
preclude a large rise in temperature reducing the likelihood that
cables would be damaged by the fire. The limited amount of combustible
materials and ignition sources, administrative controls, and lack of
credible fire scenarios, combined with the ability of the OMAs with
available margin (40 minutes) to manipulate the plant, in the unlikely
event of a fire that damages safe shutdown equipment, provides adequate
assurance that safe shutdown capability can be maintained.
The East Main Steam Safety Valve/Blowdown Tank Room has limited
combustible materials and ignition sources and lacks credible fire
scenarios, but is not provided with detection. However, since the
amount of Class A combustibles is small, there is little likelihood of
a fire occurring which could act as a pilot ignition source for the
cable insulation. In addition, the high ceiling and the large volume
would preclude a large rise in temperature where the cable trays or
conduits are routed, reducing the likelihood of cable damage. The
limited amount of combustible materials and ignition sources,
administrative controls, and lack of credible fire scenarios, combined
with the ability of the OMAs with available margin (40 minutes) to
manipulate the plant in the unlikely event of a fire that damages safe
shutdown equipment, provides adequate assurance that safe shutdown
capability can be maintained.
3.14 Feasibility and Reliability of the Operator Manual Actions
In their February 29, 2012 letter, the licensee stated that the
means to safely shutdown MPS2 in the event of a fire that does occur
and is not rapidly extinguished, as expected, has been documented in
the Appendix R Compliance report. The entire Appendix R Compliance
report was not reviewed by the NRC as part of this exemption, the
relevant information was submitted on the docket in the letters
identified above. The sections below outline the licensees basis for
the OMA's feasibility and reliability.
NUREG-1852, ``Demonstrating the Feasibility and Reliability of
Operator Manual Actions in Response to Fire,'' provides criteria and
associated technical bases for evaluating the feasibility and
reliability of post-fire OMAs in nuclear power plants. The following
provides the MPS2 analysis of these criteria for justifying the OMAs
specified in this exemption.
3.14.1 Bases for Establishing Feasibility and Reliability
The licensee stated that in establishing the assumed times for
operators to perform various tasks, a significant margin (i.e., a
factor of two) was used with respect to the required time to establish
the system function for all fire area scenarios identified in the
exemption request (with the exception of RWST flow to charging). For
example, the Time Critical Action (TCA) to establish AFW flow is
validated to be able to be completed within 22.5 minutes, which
provides a factor of two margin of the 45 minute timeframe used in the
fire scenario analysis.
The licensee stated that confirmation times for valve/breaker
manipulations was included in the action time for the OMAs. The
licensee also stated that for valves that are operated in the field, if
they are being manually opened or closed, there is local indication
plus the mechanical stops to confirm valve operation. For valves that
are throttled, the field operator is in communication with the CR
personnel who monitor
[[Page 43402]]
control board indication to confirm the proper response. The licensee
further stated that all breakers have local mechanical indication for
position verification, that all sequenced steps are coordinated from
the CR, and that the OMA times listed include this coordination.
3.14.2 Environmental Factors
The licensee stated that a review of ventilation systems for the
fire areas addressed by the exemption request concluded that no
credible paths exist that could allow the spread of products of
combustion from the area of fire origin to an area that either serves
as a travel path for OMAs or is an action location for an OMA. There is
an exception for OMA 1 in fire area R-4 which was discussed in section
3.2.4.1.1 (and below). The licensee also stated that the installed
ventilation systems are not used to perform smoke removal activity for
the fire areas discussed in the exemption request and that smoke
evacuation for these areas would be accomplished by the site Fire
Brigade utilizing portable mechanical ventilation.
The licensee stated that the performance of all the OMAs for each
of the fire areas have specific safe pathways for access and egress and
that in all cases, ELUs have been provided to ensure adequate lighting.
The licensee also stated that during a fire event, implementation of CR
actions ensure the radiation levels along these pathways, and at the
location of the OMAs, are within the normal and expected levels.
The licensee stated that area temperatures may be slightly elevated
due to a loss of normal ventilation, however, in no case would the
temperatures prevent access along the defined routes or prevent the
performance of an OMA. The licensee also stated that only OMA 1 could
occur in the fire affected area in that a fire in fire area R-4,
charging pump cubicle, could impact valve 2-CH-192 requiring the OMA to
manually open this valve. The licensee further stated that this action
would be delayed until after the fire is extinguished and the area is
ventilated and that opening valve 2-CH-192 would not be required until
the BASTs are emptied. The licensee further stated that the most
limiting time estimate is 72 minutes of Charging system operation
injecting the contents of the BASTs based on the tanks being at the TRM
minimum level at the start of the event and that during the event,
Charging may be lost or secured, and RCS inventory can meet the
Appendix R performance goal for 180 minutes. The licensee further
stated that analysis indicates that valve 2-CH-192 may not need to be
opened until 252 minutes into the event.
The licensee stated that fire barrier deviations that could allow
the spread of products of combustion of a fire to an adjacent area that
either serves as a travel path for OMAs or is an action location for an
OMA have been found to not adversely impact OMA travel paths or action
areas.
3.14.3 Equipment Functionality and Accessibility
The licensee stated that as part of the OMA validation process,
lighting, component labeling, accessibility of equipment, tools, keys,
flashlights, and other devices or supplies needed are verified to
ensure successful completion of the OMA.
The licensee stated that for each OMA, the current MPS2 Appendix R
Compliance Report indicates that operator access is assured by an
alternate path or access is not required until after the fire has been
suppressed. Where applicable, the licensee stated that OMAs have
sufficient ELUs to provide for access to the particular component and
to perform the task.
3.14.4 Available Indications
Indicators and indication cables have been evaluated by the
licensee as part of the exemption request process. Where impacts to
indication have been identified the licensee provided an alternate
method to obtain the needed indication(s).
3.14.5 Communications
The licensee stated that Operators are provided with dedicated
radio communication equipment and that the Appendix R communication
system utilizes a portion of the MPS 800 MHz trunked radio system which
consists of 800 MHz portable radio units, a CR base station
transmitter, antennas, a main communication console located inside the
CR and redundant repeaters. The licensee also stated that the CR base
station transmitter is provided to ensure two-way voice communications
with the CR without affecting plant safety systems that may have
sensitive electronic equipment located in the area and the resulting
design configuration ensures communications capability for all Appendix
R fire scenarios.
3.14.6 Portable Equipment
The licensee stated that all equipment required to complete a
required action is included in a preventative maintenance program and
is also listed in the TRM which identifies surveillances for the
equipment utilized in each OMA.
3.14.7 Personnel Protection Equipment
The licensee stated that there are no OMAs required in fire areas
identified in the exemption request that necessitate the use of self-
contained breathing apparatus. No fire areas necessitate reentry to the
area of fire origin other than described in Section 3.2.4.1.1.
3.14.8 Procedures and Training
The licensee stated that entry into AOP 2559, ``FIRE'' is at the
first indication of a fire from a panel alarm or report from the field.
If the fire is in an Appendix R area, the shift is directed to
determine if a fire should be considered Appendix R by:
1. Identifying actual or imminent damage to safe shutdown
components, switchgear, MCCs, cable trays or conduit runs;
2. Observation of spurious operation of plant components needed for
safe shutdown;
3. Observation of loss of indication, control, or function of safe
shutdown plant systems or components;
4. Observation of conflicting instrument indication for safe
shutdown systems or components; or
5. Observation of parameters associated with safe shutdown systems
or components not being within expected limits for the existing plant
configuration.
The licensee stated that AOP 2559, ``FIRE'' has various attachments
that have Appendix R egress/access routes which provide a safe pathway
to reach the required equipment necessary to complete the OMAs and that
they have confirmed that the pathways will be free of hazards to the
operators due to the subject fire.
The licensee also stated that there is an Appendix R AOP
corresponding to each Appendix R fire area, which are entered when an
Appendix R fire is declared. Operations personnel train to those AOPs
which identify the steps to perform each OMA. The licensee further
stated that time critical OMAs are also identified within operating
procedures which require that Operations personnel train to perform
these time critical activities. The OMAs presented in this exemption
request are encompassed in the time critical procedure.
The licensee further stated that the times allotted to perform
these tasks are easily achieved by experienced and inexperienced
operators during training sessions, evaluated requalification training,
and supervised walk downs and that for each case, there is sufficient
[[Page 43403]]
margin to account for the uncertainties associated with stress,
environmental factors, and unexpected delays.
3.14.9 Staffing
The licensee stated that the Operations shift staffing requirements
include one additional licensed or non-licensed operator over the
minimum TS requirement to be on duty each shift during Modes 1, 2, 3,
or 4, and that this operator is designated as the Appendix R operator
and is specified in the TRM. The licensee also stated that the number
of individuals available to respond to the OMAs is one RO, two PEOs,
and one additional licensed or non-licensed individual (Appendix R
Operator). The licensee stated that the exemption request allocated
tasks to PEO-1, PEO-2, PEO-3 and RO-1 and that one of the three PEOs
would be the TRM required Appendix R Operator. With the exception of
the panel C10 activities, the assignments are interchangeable between
the four operators, since these individuals are specified by the TS and
TRM, they are not members of the Fire Brigade and have no other
collateral duties.
The licensee stated that MPS2 has a SERO and appropriate emergency
response facilities. In the event of a declaration of an ALERT (events
which are in progress or have occurred involving an actual or potential
substantial degradation of the level of safety of the plant, with
releases expected to be limited to small fractions of the Environmental
Protection Agency, Protective Action Guideline exposure levels), ALERT
event activates the SERO organization, which is immediately staffed by
on-site personnel and is fully established with on-call personnel
within 60 minutes of the ALERT being declared. The licensee also stated
that after this time, off-shift Operations staff (e.g., personnel in
training, performing administrative functions, etc.) may be called in
as requested by the SM. The licensee further stated that many of the
OMAs are not required prior to the establishment of SERO and that the
additional staff available through SERO will improve the reliability of
these OMAs.
The licensee stated that operators are required and assumed to be
within the Protected Area and that the time lines account for the
initial response by the field Operator. The licensee also stated that
upon the announcement of a fire, the field Operators are directed to
report to the CR and await further directions. Upon a report of a fire,
the CR Operators enter AOP 2559, ``FIRE.'' The licensee further stated
that the flow path to get into an Appendix R fire scenario is, that
upon indication of a fire, the Fire Brigade is dispatched, and based on
their report or indications in the CR, an Appendix R fire may be
declared. In the development of the time lines, the Operators are
allowed 5 minutes to respond and report to the CR.
3.14.10 Demonstrations
In their letter dated February 29, 2012 the licensee provided its
validation process for the OMAs included in the exemption request. The
validation process included the following: 1. Validation Objectives; 2.
Validation Frequency; 3. Validation Methods; 4. Validation Attributes;
and 5. Validation Performance.
The licensee stated that all OMAs are encompassed in procedure COP
200.18, ``Time Critical Action Validation and Verification'' and that
an enhancement to the tracking and training on TCAs has been developed
and is currently being implemented.
The licensee stated that all of the OMAs identified are contained
in the AOPs to respond to an Appendix R Fire in the AOP Series 2579's
fire procedures for Appendix R and that during initial validation of
these procedures, the OMAs were performed and all of the time
performance objectives were met as a result of the validation.
3.14.11 Feasibility Summary
The licensee's analysis demonstrates that, for the expected
scenarios, the OMAs can be diagnosed and executed within the amount of
time available to complete them. The licensee's analysis also
demonstrates that various factors, including the factor of two time
margin, the use of the minimum BAST inventory, and the use of the CST
inventory, have been considered to address uncertainties in estimating
the time available. Therefore, the OMAs included in this review are
feasible because there is adequate time available for the Operator to
perform the required OMAs to achieve and maintain hot shutdown
following a postulated fire event. The following table summarizes the
``required'' versus ``available'' times for OMAs with time
requirements. Where a diagnosis time has been identified, it is
included as part of the required time for a particular action. Where an
action has multiple times or contingencies associated with the
``allowable'' completion time, the lesser time is used. This approach
is considered to represent a conservative approach to analyzing the
timelines associated with each of the OMAs with regard to the
feasibility and reliability of the actions included in this exemption.
All OMAs have at least 30 minutes of margin, and all but one have a
factor of two time margin available. Margin is based on using the most
limiting information from the licensee, for example, if the licensee
postulated a range of time for diagnosis, the required time below
includes the largest number in the range.
Finally, these numbers should not be considered without the
understanding that the manual actions are a fall back in the unlikely
event that the fire protection defense-in-depth features are
insufficient. In most cases there is no credible fire scenario that
would necessitate the performance of these OMAs. The licensee provided
a discussion of the activity completion times and associate margins
related to the OMAs in their June 30, 2011, and February 29, 2012
letters which are summarized in Table 3.
Table 3
----------------------------------------------------------------------------------------------------------------
Time to
Fire Area of Fire Origin Activity OMAs Available conduct Margin
time (min) OMAs (min) (min)
----------------------------------------------------------------------------------------------------------------
Fire Area R-2 (West Penetration Establish AFW Flow.... 12 45 9 36
Area, MCC B61, and the Facility Z2
Upper 4.16kV Switchgear Room and
Cable Vault).
Establish Charging 2, 6, 10, 180 66 114
Suction from BAST. 18, 19, 20
Establish Charging 1, 8 72 40 32
Suction from RWST.
[[Page 43404]]
Fire Area R-4 (Charging Pump Establish Charging 1 72 32 40
Cubicles). Suction from RWST.
Fire Area R-5 (``A'' Safeguards Establish Charging 1 72 32 40
Room, HPSI/LPSI). Suction from RWST.
Fire Area R-6 (``B'' Safeguards Establish Charging 1 72 32 40
Room, LPSI). Suction from RWST.
Fire Area R-7 (Diesel Generator Room Establish Charging 4, 5, 11 180 24 156
A). Suction from BAST.
Establish Charging 1 72 32 40
Suction from RWST.
Fire Area R-8 (Diesel Generator Room Establish Charging 1 72 32 40
B). Suction from RWST.
Fire Area R-9 (Facility Z1 DC Establish Charging 4, 5 180 24 156
Switchgear Room and Battery Room). Suction from BAST.
Fire Area R-10 (Facility Z2 DC Obtain Local BAST 18, 19 180 12 168
Equipment Room and Battery Room). Level Indication.
Fire Area R-12 (TDAFW Pump Pit)..... Establish Charging 1 72 32 40
Suction from RWST.
Fire Area R-13 (West (Facility Z1) Establish AFW Flow.... 17, 22 45 10 35
480 VAC Switchgear Room).
Establish Charging 4, 5, 16, 180 23 157
Suction from BASTs. 20, 21, 24
Fire Area R-14 (Facility Z1 Lower Establish Charging 4, 5, 13, 180 27 153
4.16kV Switchgear Room and Cable Suction from BASTs. 14, 15, 23,
Vault). 24
Fire Area R-15 (Containment Establish Charging 6, 7 180 10 170
Building). Suction from BASTs.
Establish Charging 1 72 32 40
Suction from RWST.
Fire Area R-17 (East Penetration Establish Charging 4, 5 180 24 156
Area). Suction from BASTs.
Establish Charging 1 72 32 40
Suction from RWST.
----------------------------------------------------------------------------------------------------------------
The completion times noted in the table above provide reasonable
assurance that the OMAs can reliably be performed under a wide range of
conceivable conditions by different plant crews because it, in
conjunction with the time margins associated with each action and other
installed fire protection features, account for sources of uncertainty
such as variations in fire and plant conditions, factors unable to be
recreated in demonstrations and human-centered factors.
3.14.12 Reliability
A reliable action is a feasible action that is analyzed and
demonstrated as being dependably repeatable within an available time.
The above criteria, 3.14.1 through 3.14.10 provide the staff's basis
that the actions are feasible. Section 3.14.11, provides a discussion
of the available time margin. The licensee provided a basis that the
actions were reliable, based on the available time margin; the
administrative controls such as procedures, staffing levels, and
availability of equipment; and by accounting for uncertainty in fires
and plant conditions. Therefore, the OMAs included in this review are
reliable because there is adequate time available to account for
uncertainties not only in estimates of the time available, but also in
estimates of how long it takes to diagnose a fire and execute the OMAs
(e.g., as based, at least in part, on a plant demonstration of the
actions under non-fire conditions). OMA 1 for fire area R-4 is
performed in a fire affected area and is performed after the fire is
extinguished and after the SERO is fully staffed. This OMA establishes
the RWST as the suction supply for the charging system and is not
conducted until after AFW is established and since the BASTs have a
minimum TRM specified inventory to ensure 72 minutes of flow, OMA 1 can
be completed with 40 minutes of margin.
3.15 Summary of Defense-in-Depth and Operator Manual Actions
In summary, the defense-in-depth concept for a fire in the fire
areas discussed above provides a level of safety that results in the
unlikely occurrence of fires, rapid detection, control and
extinguishment of fires that do occur and the protection of structures,
systems and components important to safety. As discussed above, the
licensee has provided preventative and protective measures in addition
to feasible and reliable OMAs that together demonstrate the licensee's
ability to preserve or maintain safe shutdown capability in the event
of a fire in the analyzed fire areas.
3.16 Authorized by Law
This exemption would allow MPS2 to rely on OMAs, in conjunction
with the other installed fire protection features, to ensure that at
least one means of achieving and maintaining hot shutdown remains
available during and following a postulated fire event, as part of its
fire protection program, in lieu of meeting the requirements specified
in III.G.2 for a fire in the analyzed fire areas. As stated above, 10
CFR 50.12 allows the NRC to grant exemptions from the requirements of
10 CFR Part 50. The NRC staff has determined that granting of this
exemption will not result in a violation of the Atomic Energy Act of
1954, as amended, or the Commission's regulations. Therefore, the
exemption is authorized by law.
[[Page 43405]]
3.17 No Undue Risk to Public Health and Safety
The underlying purpose of 10 CFR Part 50, Appendix R, Section III.G
is to ensure that at least one means of achieving and maintaining hot
shutdown remains available during and following a postulated fire
event. Based on the above, no new accident precursors are created by
the use of the specific OMAs, in conjunction with the other installed
fire protection features, in response to a fire in the analyzed fire
areas. Therefore, the probability of postulated accidents is not
increased. Also based on the above, the consequences of postulated
accidents are not increased. Therefore, there is no undue risk to
public health and safety.
3.18 Consistent with Common Defense and Security
This exemption would allow MPS2 to credit the use of the specific
OMAs, in conjunction with the other installed fire protection features,
in response to a fire in the analyzed fire areas, discussed above, in
lieu of meeting the requirements specified in III.G.2. This change, to
the operation of the plant, has no relation to security issues.
Therefore, the common defense and security is not diminished by this
exemption.
3.19 Special Circumstances
One of the special circumstances described in 10 CFR
50.12(a)(2)(ii) is that the application of the regulation is not
necessary to achieve the underlying purpose of the rule. The underlying
purpose of 10 CFR Part 50, Appendix R, Section III.G is to ensure that
at least one means of achieving and maintaining hot shutdown remains
available during and following a postulated fire event. While the
licensee does not comply with the explicit requirements of III.G.2
specifically, they do meet the underlying purpose of 10 CFR Part 50,
Appendix R, and Section III.G as a whole. Therefore, special
circumstances exist that warrant the issuance of this exemption as
required by 10 CFR 50.12(a)(2)(ii).
4.0 Conclusion
Based on the all of the features of the defense-in-depth concept
discussed above, the NRC staff concludes that the use of the requested
OMAs, in these particular instances and in conjunction with the other
installed fire protection features, in lieu of strict compliance with
the requirements of III.G.2 is consistent with the underlying purpose
of the rule. As such, the level of safety present at MPS2 is
commensurate with the established safety standards for nuclear power
plants.
Accordingly, the Commission has determined that, pursuant to 10 CFR
50.12(a), the exemption is authorized by law, will not present an undue
risk to the public health and safety, is consistent with the common
defense and security and that special circumstances are present to
warrant issuance of the exemption. Therefore, the Commission hereby
grants Dominion an exemption from the requirements of Section III.G.2
of Appendix R of 10 CFR Part 50, to utilize the OMAs discussed above at
MPS2.
Pursuant to 10 CFR 51.32, the Commission has determined that the
granting of this exemption will not have a significant effect on the
quality of the human environment (77 FR 39746).
This exemption is effective upon issuance.
Dated at Rockville, Maryland, this 12th day of July 2012.
For the Nuclear Regulatory Commission.
Michele G. Evans,
Director, Division of Operating Reactor Licensing, Office of Nuclear
Reactor Regulation.
[FR Doc. 2012-17735 Filed 7-23-12; 8:45 am]
BILLING CODE 7590-01-P