[Federal Register Volume 77, Number 28 (Friday, February 10, 2012)]
[Notices]
[Pages 7184-7211]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-3124]
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NUCLEAR REGULATORY COMMISSION
[Docket No. 50-247]
Entergy Nuclear Indian Point 2, LLC; Entergy Nuclear Operations,
Inc.; Indian Point Nuclear Generating Unit No. 2; Exemption
1.0 Background
Entergy Nuclear Operations, Inc. (Entergy or the licensee) is the
holder of Facility Operating License No. DPR-026, which authorizes
operation of Indian Point Nuclear Generating Unit No. 2 (IP2). 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.
IP2 is a pressurized-water reactor located approximately 24 miles
north of the New York City boundary line on the east bank of the Hudson
River in Westchester County, New York.
2.0 Request/Action
Title 10 of the Code of Federal Regulations (10 CFR) part 50,
Section 50.48(b), requires that nuclear power plants that were licensed
to operate 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.'' The circuit separation and
protection requirements being addressed in this request for exemption
are specified in Section III.G.2. Since IP2 was licensed to operate
before January 1, 1979, IP2 is required to meet Section lll.G.2 of
Appendix R to 10 CFR part 50.
The underlying purpose of Section III.G of Appendix R to 10 CFR
part 50 is to establish reasonable assurance that safe shutdown (SSD)
of the reactor can be achieved and maintained in the event of a
postulated fire in any plant area. Circuits which could cause
maloperation or prevent operation of redundant trains of equipment
required to achieve and maintain hot shutdown conditions as a result of
fire in a single fire area must be protected in accordance with
lll.G.2. If conformance with the technical requirements of III.G.2
cannot be assured in a specific fire area, an alternative or dedicated
shutdown capability must be provided in accordance with Section
III.G.3, or an exemption obtained in accordance with 10 CFR 50.12,
``Specific exemptions.''
By letter dated March 6, 2009, Entergy requested an exemption from
the requirements of 10 CFR part 50, Appendix R, in accordance with 10
CFR 50.12. Specifically, Entergy requested an exemption to allow the
use of Operator Manual Actions (OMAs) in lieu of meeting certain
technical requirements of III.G.2 in Fire Areas C, F, H, J, K, P, and
YD of IP2. The table below provides the dates and topics of the
submittals related to this request.
----------------------------------------------------------------------------------------------------------------
Subject Author Date Description ADAMS Accession
----------------------------------------------------------------------------------------------------------------
Exemption Request from Entergy......... March 6, 2009... Original Submittal... ML090770151.
Appendix R.
Revised Exemption Request..... Entergy......... October 1, 2009. Revision to March ML092810231
2009 submittal,
incorporated changes
to Attachment 2,
Technical Basis in
Support of Exemption
Request.
Request for Additional NRC............. January 20, 2010 Request for ML100150128
Information (RAI) 1. information on the
overall defense-in-
depth for each fire
zone..
RAI Response 1....... Entergy......... May 4, 2010..... Response to the ML101320230
staff's January 20,
2010, RAI..
RAI 2................ NRC............. August 11, 2010. RAI on reactor ML102180331
coolant system
makeup, separation
distances, etc.
RAI Response 2....... Entergy......... September 29, Response to the ML102930237
2010. staff's August 11,
2010, RAI.
RAI 3................ NRC............. December 16, RAI on reactor ML103500204
2010. coolant system
makeup.
RAI Response 3....... Entergy......... January 19, 2011 Responses to the ML110310013
staff's December 16,
2010, RAI.
Letter to revise previously Entergy......... February 10, Letter updating ML110540321
submitted information. 2011. tables contained in
previous submittals.
[[Page 7185]]
Letter to revise previously Entergy......... May 26, 2011.... Letter updating ML11158A197
submitted information. tables contained in
previous submittals.
----------------------------------------------------------------------------------------------------------------
III.G.2 establishes various protection options for providing
reasonable assurance that at least one train of systems, equipment, and
cabling required to achieve and maintain hot shutdown conditions
remains free of fire damage. In lieu of providing one of the means
specified in the regulation, Entergy requests an exemption from lll.G.2
to allow the use of OMAs to achieve and maintain hot shutdown
conditions in the event of fire in seven fire areas at IP2, Fire Areas
C, F, H, J, K, P, and YD. The licensee further subdivides these fire
areas into one or more fire zones for analysis purposes.
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 stated that
special circumstances exist because the application of the regulation
in this particular circumstance is not necessary to achieve the
underlying purpose of the rule.
In accordance with 10 CFR 50.48(b), nuclear power plants licensed
to operate 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 SSD is preserved following a fire event. The regulation
intends for licensees to accomplish this by extending the concept of
defense-in-depth to:
Prevent fires from starting.
Rapidly detect, control, and extinguish promptly those
fires that do occur.
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 SSD of the plant.
Section III.G.2 requires one of the following means to ensure that
a redundant train of SSD 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.
In its March 6, 2009, and October 1, 2009, submittals, Entergy
requested an exemption from certain technical requirements of III.G.2
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 prescribed in III.G.2 in
Fire Areas C, F, H, J, K, P, and YD. The licensee also listed an
operator action to implement emergency operating procedure (EOP) 2-FR-
H.1, ``Response To Loss Of Secondary Heat Sink.'' The NRC does not
consider implementing 2-FR-H.1 an OMA, as actions to establish reactor
coolant system decay heat removal can be performed from the control
room and there are redundant trains of equipment located outside of the
fire area of fire origin.
Each OMA included in this review consists of a sequence of tasks
that occur in various fire areas. The OMAs are initiated upon
confirmation of a fire in a particular fire area, which the licensee
has further subdivided into fire zones. Listed in the order of the fire
area of fire origin, the OMAs included in this review are as follows:
------------------------------------------------------------------------
Area of fire Operator manual
OMA origin Area name actions
------------------------------------------------------------------------
1................ C................ Auxiliary Boiler Implement EOP FR-
Feed Pump Room, H.l as directed
Elevation 18'- by EOPs and
6'' of the status trees if
Auxiliary Feed necessary to
Pump Building. establish
alternate
secondary heat
sink. Action
performed from
the control
room, so the
NRC does not
consider this
an OMA.
-----------------
2................ ................. ................ Operate turbine-
driven 22
auxiliary
feedwater (AFW)
pump upon
reentry to the
room following
the initial
hour of the
fire scenario.
-----------------
3................ ................. ................ Open or check
open 22 AFW
pump steam
supply
isolation
valves PCV-
1310A and PCV-
1310B.
-----------------
4................ ................. ................ Operate 22 AFW
pump flow
control valves
FCV-405A
(discharge to
21 steam
generator
(SG)), FCV-405B
(discharge to
22 SG), FCV-
405C (discharge
to 23 SG), and/
or FCV-405 to
align AFW flow
to selected
steam
generators.
------------------------------------------------------------------------
5................ F................ Primary Open HCV-142
Auxiliary bypass valve
Building and 227 to align
Fan House. charging pump
makeup path to
the Reactor
Coolant System
(RCS).
-----------------
[[Page 7186]]
6................ ................. ................ Align charging
pump suction
source to the
Refueling Water
Storage Tank
(RWST).
-----------------
7................ ................. ................ Transfer
instrument
buses 23 and
23A to
alternate
power.
------------------------------------------------------------------------
8................ H................ Vapor (Reactor) Fail open valves
Containment 204A (charging
Building. flow to Loop 2
hot leg) and
204B (charging
flow to Loop 1
cold leg) to
align charging
pump makeup
path to the
RCS.
-----------------
9................ ................. ................ Activate or
enable
Alternate Safe
Shutdown System
pneumatic
instruments
(steam
generator
level,
pressurizer
pressure and
level) at Fan
House local
control panel.
-----------------
10............... ................. ................ Enable Alternate
Safe Shutdown
System source-
range channel
and Loop 21 and
22 hot leg (Th)
and cold leg
(Tc)
temperature
channels.
------------------------------------------------------------------------
11............... J................ Unit 1 Control Trip breakers 52/
Room, Turbine 5A and 52-SAC
Building, on Bus 5A and
Superheater 52/6A and 52/
Building, TAO at Bus 6A
Nuclear Service and remove
Building, control power
Chemical fuses.
Systems
Building,
Administration
Building,
Screenwell
House, and Unit
2 Turbine
Building.
-----------------
12............... ................. ................ Transfer
Instrument
Buses 23 and
23A to
emergency power
source.
-----------------
13............... ................. ................ Align charging
pump suction to
RWST.
------------------------------------------------------------------------
14............... K................ Auxiliary Feed Operate transfer
Pump Building switch EDC5 and
(not including close supply
the AFW Pump breaker at
Room). substation
12FD3 to
transfer 21 AFW
Pump to
Alternate Safe
Shutdown System
power source.
-----------------
15............... ................. ................ Open 21 AFW pump
recirculation
bypass valve
BFD-77.
------------------------------------------------------------------------
16............... P................ Component Transfer 23 CCW
Cooling Water pump to
(CCW) Pump Room. Alternate Safe
Shutdown System
power feed
followed by
breaker closure
at 12FD3.
-----------------
17............... ................. ................ Start Appendix R
Diesel
Generator
(ARDG) if
normal power
and offsite
power are lost.
------------------------------------------------------------------------
18............... YD............... Outdoor (Yard) Open HCV-142
Area. bypass valve
227 to align
charging pump
makeup path to
RCS.
------------------------------------------------------------------------
In their submittals, the licensee described elements of their fire
protection program 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. 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 for a fire in the fire areas identified above.
In their March 6, 2009, and October 1, 2009, submittals, 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
because the separation requirements for equipment and electrical
circuits required by III.G.2 are not met. Specifically, the licensee
stated that noncombustible materials have been used to the maximum
extent practicable and that the introduction of combustible materials
into areas with safety-related equipment, including Fire Areas C, F, H,
K, and P, is strictly controlled by administrative procedures. The
administrative procedures govern the handling, storage, and limitations
for use of ordinary combustible materials, combustible and flammable
gases and liquids, and other combustible supplies. In addition,
periodic fire prevention inspections are performed to assess compliance
with Indian Point's programs for Control of Combustibles and Control of
Ignition Sources. The licensee stated that the administrative controls
are described in the IP2 Fire Protection Program (FPP), which is
incorporated by reference into the Updated Final Safety Analysis
Report.
The licensee stated that both thermoplastic and thermoset low-
voltage power, control, and instrument cables are installed at IP2.
Since the thermoplastic insulated cables were manufactured and
installed prior to the issuance of IEEE-383, a standard for nuclear
plant cables, they were not qualified to that standard. In its May 4,
2010 letter, the licensee stated that these cables are constructed with
an asbestos glass braid outer jacket which provides protection from
flame spread. In addition, the licensee stated that the results of
various tests, as well as an actual fire event during plant
construction, have demonstrated the ability of this type of
thermoplastic insulated cables to minimize the growth and spread of
cable fires. The licensee also stated that the likelihood of self-
[[Page 7187]]
ignited cable fires is minimized by appropriately sized electrical
protection devices (e.g., fuses and circuit breakers). The licensee
stated that all cables installed after plant construction are thermoset
cables which meet the IEEE-383 standard. The IEEE-383 standard includes
fire-retardation characteristics.
All of the fire areas in the plant are comprised of one or more
fire zones consisting of separate compartments or fire zone
delineations based on spatial separation. In addition, the licensee
stated that the localization of hazards and combustibles within each
fire zone, combined with the spatial or physical barrier separation
between zones, provides reasonable assurance that a fire that occurs
within a particular zone will be confined to that zone. As such, the
licensee provided a characterization of the defense-in-depth that is
present in each of the fire zones containing multiple trains of SSD
equipment. The licensee further stated that for each of the fire zones
where OMAs are performed, the adequacy of non-rated fire barriers was
evaluated to ensure that they can withstand the hazards associated with
the area. Therefore, this review evaluates the defense-in-depth
provided in each of the zones of concern.
In its submittals, the licensee provided a summary of plant-
specific fire protection features provided for each fire zone
identified in its request including an account of combustible loading
(both fixed and transient), ignition sources, detection, suppression,
administrative controls, and identified any additional fire protection
features that may be unique to the fire zone, such as electrical
raceway fire barriers. In its responses, the licensee stated that
combustibles and sources of ignition are tightly controlled by
administrative controls programs and that the areas included in this
exemption are not shop areas so hot work activities (such as welding)
are infrequent and appropriate administrative controls (e.g., hot work
permits, fire watch, and supervisory controls) are in place if hot work
activities do occur. The licensee also stated that the original
installation of the suppression and detection systems was accepted by
the NRC staff in safety evaluation reports (SERs) dated January 31,
1979, and a supplement dated October 31, 1980, and that there are no
code compliance items that present an adverse impact to the
implementation of the requested OMAs. Within the fire zones of concern
to its request, the licensee stated that fire-rated assemblies are only
used and credited for intra-zone separation of redundant SSD equipment
trains in part of Fire Area F (Fire Zone 7A) and part of Fire Area P
(Fire Zone 1). The fire-rated assemblies consist of a Hemyc Electrical
Raceway Fire Barrier System (ERFBS) and have been evaluated to ensure
they are adequate for the hazards of the areas of installation.
Entergy stated that for each of the fire areas addressed in this
evaluation, Post-Fire Safe Shutdown (PFSSD) is principally accomplished
by remaining in the Central Control Room (CCR) and conducting a normal
(non-alternative) shutdown. In all cases, the identified OMAs mitigate
conditions where certain technical requirements of III.G.2 are not
satisfied.
Entergy further stated that the OMAs required for achieving and
maintaining hot shutdown conditions are feasible, reliable, and are not
impacted by environmental conditions (radiation, lighting, temperature,
humidity, smoke, toxic gas, noise, fire suppression discharge, etc.)
associated with fires in III.G.2 areas. The feasibility and reliability
of the requested OMAs are addressed in Section 4.0 of this evaluation.
NRC Staff Observations
In its May 4, 2010, response to RAI-07.1, the licensee stated that
no credit was taken for immediate and proactive OMA response by plant
operators upon the receipt of a fire detection alarm in any of the
identified fire zones. Instead, the licensee stated that OMAs are
initiated upon the detection of operating abnormalities or failures
caused by a postulated fire event. In this same response, the licensee
stated that they conducted exercises using the plant simulator to
evaluate the feasibility of the OMAs where a fire condition or a
spontaneous reactor trip caused by a fire was announced at the outset
of the simulation followed by the failure of discrete components that
are subject to impairment due to fire damage to cables or components
resulting from a fire in the area of concern. For fires originating in
fire zones lacking fire detection and/or automatic fire suppression
systems, the NRC staff considers it improbable that the operators would
properly indentify that the indications were the result of a fire
instead of some other fault. In addition, the operators would be
delayed in positively identifying the location of the fire based on
these indirect and ambiguous indicators. Therefore, for some scenarios
involving fire zones that lack fire detection systems, operators are
unlikely to identify and respond to a fire event in a manner that
prompts them to perform certain OMAs prior to a significant degradation
of the plant's condition. This becomes especially relevant for OMAs
that are required to be completed within a relatively short period of
time, e.g., within about 30 minutes, or have limited margins available
to complete the required actions.
For OMAs that are required to be completed within a short period of
time, the NRC staff evaluates if operators can reliably perform the
OMA. In order to be able to perform OMAs reliably, it is important that
operators are able to promptly implement any required action based on
clear indications. Indirect indicators and diagnostic analysis would
result in delayed action to initiate the appropriate OMAs and would
impair their reliable completion. For example, loss of control or
indication for a pump or other affected component could result from the
power supply circuit breaker opening due to an electrical fault other
than a fire, and the operator might delay taking actions for a fire
while investigating other potential and more-likely causes. The NRC
staff documented a position on procedures and training for such actions
in Section 4.2.9 of NUREG-1852, ``Demonstrating the Feasibility and
Reliability of Operator Manual Actions in Response to Fire,'' which
notes that the procedures for reactive actions should clearly describe
the indications which prompt initiation of the actions. Therefore,
where OMAs need to be performed within a short period of time, fire
zones crediting those OMAs are expected to have more robust defense-in-
depth and clear, direct procedures than fire zones that have a
significant margin in their OMA performance times.
In the August 11, 2010 RAI-02.1 and RAI-06.1, and the December 16,
2010 RAI-01.1, the NRC staff requested that the licensee describe the
spatial separation between redundant trains of equipment. However, the
licensee's responses only provided information regarding the separation
between ignition sources and safe shutdown equipment and no information
regarding separation between redundant trains of equipment within the
fire area. For example, in its September 29, 2010 response to RAI-06.1
the licensee stated that ``The cables serving valves 204A and 204B are
routed within Containment (Fire Area H) in raceways which are not
separated by 20 feet at all locations, nor are other separation
measures as prescribed by III.G.2 (f) provided.'' During a
clarification call with the licensee, the licensee did not provide any
dimensional data on train separation. Without dimensional data on train
separation, the staff has conservatively assumed that there is no
[[Page 7188]]
discernable separation between redundant trains of equipment.
In addition, the licensee noted that the introduction of
combustible materials into most areas included in its request was
limited via administrative procedures such as EN-DC-161, ``Control of
Combustibles.'' The licensee stated that Fire Area J did not contain
safety-related systems or components and was not addressed by this
procedure. The NRC staff notes that the licensee requested OMAs for
Fire Area J and that alternate shutdown equipment and several cables
associated with normal safe-shutdown equipment are located in this
area. The licensee stated that operator rounds are performed each shift
in Fire Area J that would monitor the presence of combustibles that
could present an unacceptable fire safety challenge. In addition, the
licensee stated that procedures OAP-017, ``Plant Surveillance and
Operator Rounds'' and EN-MA-132, ``Housekeeping,'' include guidance for
monitoring general area cleanliness including monitoring for
accumulations of combustibles. The NRC staff notes that the combustible
material controls procedures for this fire area are not as robust as
for safety-related areas, and therefore results in a reduction in the
defense-in-depth for the impacted fire zones.
Specific Area or Zone Discussion
Each of the fire areas or zones included in this exemption is
analyzed below with regard to how the concept of defense-in-depth is
achieved for each area or zone and the role of the OMAs in the overall
level of safety provided for each area or zone.
3.1 Fire Area C--Auxiliary Boiler Feed Pump Room, Elevation 18'-6'' of
the Auxiliary Feed Pump Building (Fire Zone 23--Auxiliary Boiler Feed
Pump (ABFP) Room, Elevation 18'-6'')
3.1.1 Fire Prevention
Fire Area C consists of a single room (the ABFP Room or the
Auxiliary Feedwater (AFW) Pump Room) and is designated as Fire Zone 23.
Note that the pumps which supply water to the steam generators
following a reactor trip are generically known as AFW pumps, but at IP2
they are also called Auxiliary Boiler Feed Pumps. The licensee stated
that the fire loading in this area is low and that fixed combustibles
consist of fire retardant cable insulation. The licensee stated that
small quantities of lube oil and Class A combustibles are present but
those do not pose a credible challenge to components of concern located
in the zone. The licensee also stated that the ignition sources in the
area consist of cable runs, junction boxes, motors, pumps, and
electrical panels.
3.1.2 Detection, Control, and Extinguishment
The licensee stated that Fire Zone 23 does not have a fire
suppression system installed but does have an area-wide, ionization
smoke detection system installed, which would provide early
notification of a fire and assist in a prompt fire brigade response.
The licensee also stated that the detection system was designed and
installed in accordance with National Fire Protection Association
(NFPA) standard NFPA 72D, 1975 Edition.
3.1.3 Preservation of Safe Shutdown Capability
The licensee stated that Fire Zone 23 has a ceiling height of
approximately 14'-0'' and an approximate floor area of 1,210 square
feet. This fire zone contains the three AFW pumps (21, 22, and 23) and
their discharge valves used to supply water to the steam generators for
reactor coolant system decay heat removal when the normal feedwater
system is not available, such as following a reactor trip. The licensee
stated that a radiant energy shield is installed between 21 AFW pump
and 23 AFW pump and that the power cables for 23 AFW pump are wrapped
in Hemyc fire barrier material rated for 30 minutes. The licensee
stated that damage to the control or instrument cables in the overhead
trays could present an immediate impact on redundant AFW trains. As
discussed in section 3.0 above, the licensee did not identify any
separation between credited and redundant trains of equipment.
3.1.4 OMAs Credited for a Fire in Fire Area C (Fire Zone 23)
3.1.4.1 OMA 1--Implement 2-FR-H.1 If Necessary to Establish
Alternate Secondary Heat Sink
The licensee stated that for a worst case fire scenario, OMAs to
restore AFW functionality would be implemented after a period of 1 hour
following fire initiation. This time is provided to extinguish the fire
and clear the smoke from the fire area. In the unlikely event that
control and indication for all three AFW pumps is lost during the
initial hour of a fire event, the licensee stated that Emergency
Operating Procedure EOP 2-FR-H.1, ``Response to Loss of Secondary Heat
Sink,'' can be implemented to provide the reactor coolant heat removal
function using the normal feedwater system or feed-and-bleed cooling
with safety injection pumps. Since actions to remove reactor coolant
system decay heat can be performed from the CCR (no OMAs are required
in the field), this action is included for completeness only. Since no
exemption is being requested, this OMA is not part of this exemption.
In a letter dated September 14, 1988, the licensee had described the
use of EOP 2-FR-H.1 to the NRC, and by letter dated January 12, 1989,
the NRC staff concluded that the licensee's clarifications to the fire
protection program conformed with NRC fire protection guidelines and
requirements and were acceptable, so the use of EOP 2-FR-H.1 is
considered to already be part of the licensee's licensing basis.
3.1.4.2 OMA 2--Operate 22 AFW Pump (Turbine-Driven)
The licensee stated that all three AFW pumps are within this area
and associated cables are routed in this area. According to the
licensee, the cables of concern are typically routed in rigid steel
conduits and located between 8.9 feet and 10.8 feet above the floor.
The OMAs for this area are only needed if all three AFW pumps are
affected by the fire. The licensee stated that the diagnostic indicator
for this scenario would be a loss of control or indication for 22 AFW
pump from the CCR or indication of decreasing level in all steam
generators as viewed at recorders LR-417, 427, 437, and 447. In the
event that this does occur, OMAs 2, 3, and 4
are available to operate 22 AFW Pump. OMA 2 will open PCV-1139
to admit steam, operate HCV-1118 at the pump to control speed, and
operate PCV-1213 as necessary to regulate pump bearing cooling water.
Since these actions are required to be performed in the zone where the
fire occurs, a 60-minute waiting period prior to operator reentry into
the area is described in the submittal. The licensee stated that they
allotted 60 minutes before performing OMA 2 to allow the fire
brigade to perform its fire fighting operations and for the area to be
made tenable prior to entering to perform certain OMAs. In Table RAI-
08.1-1 of its February 10, 2011 submittal, the licensee indicated that
the OMA initiator (postulated fire-induced failure) is located in Fire
Zone 23 as is the OMA performance location. The licensee also provided
a comment in the same table establishing the 60-minute duration of the
waiting period.
If OMA 2 becomes necessary, the licensee stated that they
have assumed a 60-minute period before re-entering the fire area, a
4.5-minute diagnosis period, which is assumed to transpire during the
60-minute waiting period,
[[Page 7189]]
and that the required time to perform the action is 22 minutes, which
results in a total required time of 82 minutes. The licensee is
crediting the use of EOP 2-FR-H.1 until OMAs 2, 3,
and 4 can be accomplished. Since there is defense-in-depth
including full area fire detection and limited combustibles, and EOP 2-
FR-H.1 can be used to perform the reactor coolant system heat removal
function while OMA 2 is being implemented, the NRC staff finds
this OMA acceptable.
3.1.4.3 OMA 3--Open or Check Open 22 AFW Pump Steam Supply
Isolation Valves
This OMA is one of the three OMAs needed to operate the 22 AFW
pump, as described in the previous section. OMA 3 would open
the 22 AFW pump steam supply pressure control valves PCV-1310A and PCV-
1310B in Fire Area K.
If OMA 3 becomes necessary, the licensee stated that they
have assumed a 4.5-minute diagnosis period, and that the required time
to perform the action is 15 minutes, which results in a total required
time of 19.5 minutes. The licensee is crediting the use of EOP 2-FR-H.1
until OMAs 2, 3, and 4 can be accomplished.
Since there is defense-in-depth including full area fire detection and
limited combustibles, and EOP 2-FR-H.1 can be used to perform the
reactor coolant system heat removal function while OMA 3 is
being implemented, the NRC staff finds this OMA acceptable.
3.1.4.4 OMA 4--Operate 22 AFW Pump Flow Control Valves To
Align AFW Flow to Selected Steam Generators
This OMA is one of the three OMAs needed to operate the 22 AFW
pump, as described in the previous sections. OMA 4 would
operate FCV-405A (discharge to 21 SG) and FCV-405B (discharge to 22 SG)
in the AFW Pump Room, upon reentry to the room following the initial
60-minute waiting period.
If OMA 4 becomes necessary, the licensee stated that they
have assumed a 60-minute period before re-entering the fire area, a
4.5-minute diagnosis period, which is assumed to transpire during the
60-minute waiting period, and that the required time to perform the
action is 22 minutes, which results in a total required time of 82
minutes. The licensee is crediting the use of EOP 2-FR-H.1 until OMAs
2, 3, and 4 can be accomplished. Since there
is defense-in-depth including full area fire detection and limited
combustibles, and EOP 2-FR-H.1 can be used to perform the reactor
coolant system heat removal function while OMA 4 is being
implemented, the NRC staff finds this OMA acceptable.
3.1.5 Conclusion for Fire Area C (Fire Zone 23)
The NRC staff had previously issued an exemption from III.G.2 for
Fire Zone 23 in 1984 (ML003776266). In that exemption, the NRC staff
found that the low fire load and features such as fire wrap on the 23
AFW pump cables justified an exemption. By letter dated January 12,
1989, the NRC staff concluded that the licensee's clarifications to the
fire protection program, which in part described the use of EOP 2-FR-
H.1, conform with NRC fire protection guidelines and requirements and
were acceptable. The NRC staff notes that the fire detection in this
fire zone will clearly alert the operators to take actions for a fire.
Therefore, the NRC staff concludes that with the defense-in-depth
including full area fire detection and limited combustibles, OMAs
2, 3, and 4, along with EOP 2-FR-H.1, are
acceptable for maintaining the reactor coolant system heat removal
function and that the III.G.2 exemption for Fire Zone 23 remains valid.
3.2 Fire Area F--Primary Auxiliary Building and Fan House (Fire Zone
5A--Sampling Room, Elevation 80'-0'')
3.2.1 Fire Prevention
The licensee stated that the fire loading in this fire zone is
moderate and that the fixed combustibles are primarily cable
insulation. The licensee also stated that the ignition sources in the
fire zone consists of cable runs, junction boxes, and electrical
panels.
3.2.2 Detection, Control, and Extinguishment
The licensee stated that Fire Zone 5A does not have fire detection
or fire suppression systems installed.
3.2.3 Preservation of Safe Shutdown Capability
The licensee stated that Fire Zone 5A has a ceiling height of
approximately 14'-0'' and an approximate floor area of 150 square feet.
This fire zone contains cables which could affect the position of
valves LCV-112B and LCV-112C. These valves provide water to the suction
of the charging pumps. As discussed in Section 3.0 above, the licensee
could not demonstrate any separation between credited and redundant
trains of equipment.
3.2.4 OMAs Credited for a Fire in Fire Area F (Fire Zone 5A)
3.2.4.1 OMA 6--Align Charging Pump Suction to Refueling Water
Storage Tank (RWST)
The licensee stated that a postulated fire in Fire Area F could
present the potential for immediate damage to the one charging pump
(there are three charging pumps) that is normally in service during
power operations by affecting the source of water to the suction of the
pump. The licensee stated that the 21 Charging Pump is credited for
accomplishing the RCS makeup function in the event of fire in Fire Area
F. In the event that the 21 Charging Pump is in operation during a fire
in Fire Area F, and fire damage causes valve LCV-112C to spuriously
close, the 21 Charging Pump could be damaged due to a loss of suction.
For a fire in Fire Area F, the licensee stated that alignment of the
charging suction flowpath to the RWST is established by OMAs to close
valve LCV-112C and open normally closed manual valve 288, which
provides a bypass path around valve LCV-112B. To open valve 288, the
licensee stated that operators must reenter Fire Area F following a
fire.
If a fire were to occur in Fire Zone 5A and cause LCV-112C to
spuriously close, the licensee stated that OMA 6 is available
to restore or maintain the necessary function (RCS makeup) to the
affected equipment (Charging Pumps) and align charging pump suction to
the RWST by closing the volume control tank (VCT) outlet valve LCV-112C
and opening RWST manual bypass valve 288. If OMA 6 becomes
necessary, the licensee stated that they have assumed a 60-minute
waiting period before re-entering the fire area, a 14-minute diagnosis
period, which is assumed to transpire during the 60-minute waiting
period, and that the required time to perform the action is 18 minutes,
which results in a total required time of 78 minutes, while the time
available to restore makeup flow to the RCS is 75 minutes. Therefore,
there is insufficient margin available to perform the OMA for all fire
zones in Fire Area F.
3.2.5 Conclusion for Fire Area F (Fire Zone 5A)
Since the licensee described postulated fire scenarios and Fire
Zone 5A lacks an automatic fire detection or automatic suppression
system, and any discernable separation between the credited and
redundant equipment in the area, it is possible that a fire would not
be detected and extinguished in a reasonable amount of time to ensure
that at least one train of equipment
[[Page 7190]]
remains free of fire damage or allow reentry to the area to perform
OMAs. Additionally, OMA 6 cannot be completed in a timely
manner for any fire in Fire Area F. Thus, OMA 6 does not
provide assurance that safe shutdown capability will be maintained
following the postulated fire events. Therefore, the NRC staff finds
that the defense-in-depth is insufficient to demonstrate reasonable
assurance that safe shutdown can be achieved for a fire in Fire Zone 5A
and that an exemption from III.G.2 based on OMA 6 cannot be
granted for Fire Zone 5A.
3.3 Fire Area F--Primary Auxiliary Building and Fan House (Fire Zone 6-
22 Charging Pump Room, Elevation 80'-0'')
3.3.1 Fire Prevention
The licensee stated that the fire loading in this area is low and
that the fixed combustibles are cable insulation, lube oil, and
plastic. Transient combustibles consist of trash, paint, lube oil, and
radiation boundaries. The licensee also stated that the ignition source
in the area is the 22 charging pump motor.
3.3.2 Detection, Control, and Extinguishment
The licensee stated that Fire Zone 6 has an automatic fire
detection system installed but does not have an automatic fire
suppression system installed. The licensee also stated that the
detection system was designed and installed in accordance with NFPA
72D, 1975 Edition.
3.3.3 Preservation of Safe Shutdown Capability
The licensee stated that Fire Zone 6 has a ceiling height of
approximately 15'-6'' and an approximate floor area of 282 square feet.
As discussed in Section 3.0 above, the licensee could not demonstrate
any separation between credited and redundant trains of equipment. The
licensee stated that cable YZ1-JB5 associated with valve LCV-112C and
cables PL2-M41 and PL2-M42 associated with instrument buses 23 and 23A
are located in this area and that they are located 12 feet, 6.8 feet,
and 15.6 feet, respectively, from the primary ignition source in the
zone, the 22 charging pump motor.
3.3.4 OMAs Credited for a Fire in Fire Area F (Fire Zone 6)
3.3.4.1 OMA 6--Align charging pump suction to RWST
OMA 6 was evaluated in Sections 3.2.4.1 and 3.2.5 above.
As stated in Section 3.2.4.1, there is insufficient margin to perform
OMA 6 for any fire zone in Fire Area F.
3.3.4.2 OMA 7--Transfer Instrument Buses 23 and 23A to
Alternate Power
The licensee stated that if indication of instrument buses 23 and
23A is lost in the CCR, OMA 7 may be necessary to transfer
both buses to their alternate power supply. If OMA 7 becomes
necessary, the licensee stated that they have assumed a 5.5-minute
diagnosis period and that the required time to perform the action is 2
minutes, while the time available is 30 minutes, which results in 22.5
minutes of margin.
3.3.5 Conclusion for Fire Area F (Fire Zone 6)
Since the licensee described postulated fire scenarios and Fire
Zone 6 lacks an automatic fire suppression system and any discernable
separation between the credited and redundant equipment in the area, it
is possible that a fire would not be extinguished in a reasonable
amount of time to ensure that at least one train of equipment remains
free of fire damage or allow reentry to the area to perform OMAs. The
NRC staff finds that the defense-in-depth is insufficient to
demonstrate reasonable assurance that safe shutdown can be achieved for
a fire in Fire Zone 6. OMA 6 was found to be unacceptable for
this fire zone. OMA 7 has insufficient time available
considering the lack of fire suppression and therefore is unacceptable
for this fire zone. Therefore, the staff finds that an exemption from
III.G.2 based on these OMAs cannot be granted for Fire Zone 6.
3.4 Fire Area F--Primary Auxiliary Building and Fan House (Fire Zone
7A--Corridor, Elevation 80'-0'')
3.4.1 Fire Prevention
The licensee stated that the fire loading in this area is low and
that the fixed combustibles are cable insulation and electrical
cabinets, and that transient combustibles consist of trash, flammable
liquids, plastic, cellulose, and radiation boundaries. The licensee
also stated that the ignition sources in the area consist of cable
insulation, junction boxes, and electrical panels.
3.4.2 Detection, Control, and Extinguishment
The licensee stated that Fire Zone 7A has an automatic fire
detection system installed but does not have an automatic fire
suppression system installed. The licensee also stated that the
detection system was designed and installed in accordance with NFPA
72D, 1975 Edition.
3.4.3 Preservation of Safe Shutdown Capability
The licensee stated that Fire Zone 7A has a ceiling height of
approximately 16'-0'' and an approximate floor area of 6,000 square
feet. The licensee also stated that the power cable from transfer
switch EDF-9 to 23 component cooling water CCW pump motor is wrapped
with Hemyc fire barrier material rated for 30 minutes. As discussed in
Section 3.0 above, the licensee could not demonstrate any separation
between credited and redundant trains of equipment. The licensee stated
that cable YZ1-JB5 associated with valve LCV-112C and cables PL2-M41
and PL2-M42 associated with instrument buses 23 and 23A are located in
this area.
3.4.4 OMAs Credited for a Fire in Fire Area F (Fire Zone 7A)
3.4.4.1 OMA 6--Align Charging Pump Suction to RWST
OMA 6 was evaluated in Sections 3.2.4.1 and 3.2.5 above.
As stated in Section 3.2.4.1, there is insufficient margin to perform
OMA 6 for any fire zone in Fire Area F.
3.4.4.2 OMA 7--Transfer Instrument Buses 23 and 23A to
Alternate Power
The licensee stated that if indication of instrument buses 23 and
23A is lost in the CCR, OMA 7 may be necessary to transfer
both buses to their alternate power supply. If OMA 7 becomes
necessary, the licensee stated that they have assumed a 5.5-minute
diagnosis period and that the required time to perform the action is 2
minutes, while the time available is 30 minutes, which results in 22.5
minutes of margin.
3.4.5 Conclusion for Fire Area F (Fire Zone 7A)
Since the licensee described postulated fire scenarios and Fire
Zone 7A lacks an automatic fire suppression system and any discernable
separation between the credited and redundant equipment in the area, it
is possible that a fire would not be extinguished in a reasonable
amount of time to ensure that at least one train of equipment remains
free of fire damage or allow reentry to the area to perform OMAs. The
NRC staff finds that the defense-in-depth is insufficient demonstrate
reasonable assurance that safe shutdown can be achieved for a fire in
Fire Zone 7A. OMA 6 was found to be unacceptable for this fire
zone. OMA 7 has insufficient time available considering the
lack of fire suppression and therefore is unacceptable for this fire
zone. Therefore, the staff finds that
[[Page 7191]]
an exemption from III.G.2 based on these OMAs cannot be granted for
Fire Zone 7A.
3.5 Fire Area F--Primary Auxiliary Building and Fan House (Fire Zone
22A--Valve Corridor, Elevation 98'-0'')
3.5.1 Fire Prevention
The licensee stated that the fire loading in this area is low and
that there are no fixed or transient combustibles in this zone, except
for small amounts of cable insulation. The licensee also stated that
the ignition sources in the area consist of electrical cabinets.
3.5.2 Detection, Control, and Extinguishment
The licensee stated that Fire Zone 22A does not have an automatic
fire detection or automatic suppression system installed.
3.5.3 Preservation of Safe Shutdown Capability
The licensee stated that Fire Zone 22A has a ceiling height of
approximately 14'-0'' and an approximate floor area of 115 square feet.
The licensee stated that if cables for LCV-112C are affected, it may be
necessary to align an alternate water supply to the charging pump
suction. The licensee stated that cables associated with valves LCV-
112C and LCV-112B are located in Fire Zone 22A.
3.5.4 OMAs Credited for a Fire in Fire Area F (Fire Zone 22A)
3.5.4.1 OMA 6--Align charging pump suction to RWST
OMA 6 was evaluated in Sections 3.2.4.1 and 3.2.5 above.
As stated in Section 3.2.4.1, there is insufficient margin to perform
OMA 6 for any fire zone in Fire Area F.
3.5.5 Conclusion for Fire Area F (Fire Zone 22A)
Since the licensee described postulated fire scenarios and Fire
Zone 22A lacks any automatic fire detection or automatic suppression
system, it is possible that a fire would not be extinguished in a
reasonable amount of time to ensure that at least one train of
equipment remains free of fire damage or allow reentry to the area to
perform OMAs. Additionally, there is insufficient margin available for
the OMA credited in this area to provide assurance that safe shutdown
capability will be maintained following the postulated fire events.
Therefore, the staff finds that the defense-in-depth is insufficient to
demonstrate reasonable assurance that safe shutdown can be achieved for
a fire in Fire Zone 22A and that an exemption from III.G.2 based on OMA
6 cannot be granted for Fire Zone 22A.
3.6 Fire Area F--Primary Auxiliary Building and Fan House (Fire Zone
27A--Corridor, Elevation 98'-0'')
3.6.1 Fire Prevention
The licensee stated that the fire loading in this area is moderate
and that the fixed combustibles in this zone consist of cable
insulation, vinyl covers, control cabinets and panels, plastic, and
office supplies and that transient combustibles consist of trash,
rubber, paint, and radiation boundaries. The licensee also stated that
the ignition sources in the area consist of cable, junction boxes, dry
transformers, motor control center (MCC) vertical panels, and
electrical panels.
3.6.2 Detection, Control, and Extinguishment
The licensee stated that Fire Zone 27A has an automatic fire
detection system installed but does not have an automatic fire
suppression system installed. The licensee also stated that the
detection system was designed and installed in accordance with NFPA
72D, 1975 Edition.
3.6.3 Preservation of Safe Shutdown Capability
The licensee stated that Fire Zone 27A has a ceiling height of
approximately 15'-0'' and an approximate floor area of 5,450 square
feet. The licensee stated that cables associated with valves LCV-112C,
LCV-112B, HCV-142 and 227 are also located in this fire zone. As
discussed in Section 3.0 above, the licensee could not demonstrate any
separation between credited and redundant trains of equipment.
3.6.4 OMAs Credited for a Fire in Fire Area F (Fire Zone 27A)
3.6.4.1 OMA 5--Align Charging Pump Makeup Path to RCS
The licensee stated that in order to ensure a reliable charging
makeup path to the reactor coolant system (RCS), air-operated valve
HCV-142 must remain open or bypass valve 227, which is normally motor-
operated and normally closed, must be opened. The licensee stated that
air-operated valve HCV-142 is assumed to fail closed as designed in
response to a loss of instrument air. The licensee stated that if HCV-
142 were to close in response to a loss of instrument air, and cables
for valve 227 are damaged in a manner that causes normally closed
motor-operated valve 227 to remain closed and unable to be opened
remotely from the CCR, OMA 5 would be used to locally open
bypass valve 227 in Fire Area A to restore or maintain a reliable
charging pump flow path to the RCS.
If OMA 5 becomes necessary, the licensee stated that they
have assumed a 60-minute waiting period before re-entering the fire
area, a 14-minute diagnosis period, which is assumed to transpire
during the 60-minute waiting period, and that the required time to
perform the action is 14 minutes, which provides a total required time
of 74 minutes while the time available is 75 minutes, which provides 1
minute of margin. Although there is fire detection in this zone, the
NRC staff finds that 1 minute of margin is insufficient to ensure the
OMA can be accomplished reliably. Therefore, the NRC staff finds that
OMA 5 is unacceptable for a fire which initiates in Fire Zone
27A or for any fire zone in Fire Area F.
3.6.4.2 OMA 6--Align Charging Pump Suction to RWST
OMA 6 was evaluated in Sections 3.2.4.1 and 3.2.5 above.
As stated in Section 3.2.4.1, there is insufficient margin to perform
OMA 6 for any fire zone in Fire Area F.
3.6.5 Conclusion for Fire Area F (Fire Zone 27A)
Since the licensee described postulated fire scenarios and Fire
Zone 27A lacks an automatic fire suppression system and any discernable
separation between the credited and redundant equipment in the area, it
is possible that a fire would not be extinguished in a reasonable
amount of time to ensure that at least one train of equipment remains
free of fire damage or allow reentry to the area to perform OMAs. Also,
the NRC staff finds that OMAs 5 and 6 are
unacceptable for a fire which initiates in Fire Zone 27A or for any
fire zone in Fire Area F. Therefore, the staff finds that the defense-
in-depth is insufficient to demonstrate reasonable assurance that safe
shutdown can be achieved for a fire in Fire Zone 27A and that an
exemption from III.G.2 based on OMA 5 and 6 cannot be
granted for Fire Zone 27A.
3.7 Fire Area F--Primary Auxiliary Building and Fan House (Fire Zone
33A--MCC 26AA and MCC 26BB Room, Elevation 98'-0'')
3.7.1 Fire Prevention
The licensee stated that the fire loading in this area is moderate
and that the fixed combustibles in this zone consist of cable
insulation and electrical panels and that transient combustibles
consist of trash, paint, and radiation
[[Page 7192]]
boundaries. The licensee also stated that the ignition sources in the
area consist of cables, junction boxes, dry transformers, MCC vertical
panels, and electrical cabinets.
3.7.2 Detection, Control, and Extinguishment
The licensee stated that Fire Zone 33A does not have an automatic
fire detection or automatic suppression system installed.
3.7.3 Preservation of Safe Shutdown Capability
The licensee stated that Fire Zone 33A has an approximate floor
area of 1,122 square feet and is open to Fire Zone 27A above. The
licensee stated that cables associated with charging pump makeup valves
HCV-142 and 227 are located in this fire zone. As discussed in Section
3.0 above, the licensee could not demonstrate any separation between
credited and redundant trains of equipment.
3.7.4 OMAs Credited for a Fire in Fire Area F (Fire Zone 33A)
3.7.4.1 OMA 5--Align Charging Pump Makeup Path to RCS
OMA 5 was evaluated in Section 3.6.4.1 above. As stated in
Section 3.6.4.1, 1 minute of margin for OMA 5 is too low to
credit OMA 5 as being a reliable method of restoring the
charging pump flow path to the RCS for any fire zone in Fire Area F.
3.7.5 Conclusion for Fire Area F (Fire Zone 33A)
Since the licensee described postulated fire scenarios and Fire
Zone 33A lacks an automatic fire detection system or automatic
suppression system, and any discernable separation between the credited
and redundant equipment in the area, it is possible that a fire would
not be extinguished in a reasonable amount of time to ensure that at
least one train of equipment remains free of fire damage or allow
reentry to the area to perform OMAs. There is insufficient margin
available for OMA 5 for any fire in Fire Area F to provide
assurance that safe shutdown capability will be maintained following
the postulated fire events. Therefore, the staff finds that the
defense-in-depth is insufficient to demonstrate reasonable assurance
that safe shutdown can be achieved for a fire in Fire Zone 33A and that
an exemption from III.G.2 based on OMA 5 cannot be granted for
Fire Zone 33A.
3.8 Fire Area F--Primary Auxiliary Building and Fan House (Fire Zone
59A--Fan House Elevation 72'-0'', 80'-0'', and 92'-0)
3.8.1 Fire Prevention
The licensee stated that the fire loading in this area is high and
that the fixed combustibles in this zone consist of charcoal and cable
insulation and that transient combustibles consist of trash, paint, and
radiation boundaries. The licensee also stated that the ignition
sources in the area consist of electrical cabinets.
3.8.2 Detection, Control, and Extinguishment
The licensee stated that Fire Zone 59A has a partial automatic fire
suppression system installed at the charcoal filter housings and a
partial automatic fire detection system installed that consists of
Thermistor wire for the charcoal filters and an ionization detector
outside the charcoal filter enclosure on the 72'-0'' elevation. The
licensee also stated that the detection system was designed and
installed in accordance with NFPA 72D, 1967 Edition and the fire
suppression system was designed and installed in accordance with NFPA
13, 1972 Edition and NFPA 15, 1969 Edition. The partial fire detection
system may not be effective at detecting fires in other areas of this
fire zone, as it is located on the lower level of the fire zone.
3.8.3 Preservation of Safe Shutdown Capability
The licensee stated that Fire Zone 59A has an approximate floor
area of 1,400 square feet and an approximate ceiling height of 29'-0''.
Fire Zone 59A contains cable ECD3-EXF6/2, which is associated with
motor-operated valve 227.
3.8.4 OMAs Credited for a Fire in Fire Area F (Fire Zone 59A)
3.8.4.1 OMA 5--Align Charging Pump Makeup Path to RCS
OMA 5 was evaluated in Section 3.6.4.1 above. As stated in
Section 3.6.4.1, 1 minute of margin for OMA 5 is too low to
credit OMA 5 as being a reliable method of restoring the
charging pump flow path to the RCS for any fire zone in Fire Area F.
3.8.5 Conclusion for Fire Area F (Fire Zone 59A)
Since the licensee described postulated fire scenarios and Fire
Zone 59A has a high combustible loading and lacks an automatic fire
detection system or automatic suppression system throughout the zone,
except where installed at the charcoal filters, it is possible that a
fire would not be detected and extinguished in a reasonable amount of
time to ensure that at least one train of equipment remains free of
fire damage or allow reentry to the area to perform OMAs. There is
insufficient margin available for OMA 5 for any fire in Fire
Area F to provide assurance that safe shutdown capability will be
maintained following the postulated fire events. Therefore, the staff
finds that the defense-in-depth is insufficient to demonstrate
reasonable assurance that safe shutdown can be achieved for a fire in
Fire Zone 59A and that an exemption from III.G.2 based on OMA
5 cannot be granted for Fire Zone 59A.
3.9 Fire Area H--Containment Building (Fire Zone 70A--23 and 24 Reactor
Coolant Pump Area, Elevation 46-0'')
3.9.1 Fire Prevention
The licensee stated that the fire loading in this area is low and
that the fixed combustibles in this zone consist of cable insulation
and reactor coolant pump (RCP) lube oil and that transient combustibles
are administratively controlled. The licensee also stated that the
ignition sources in the area consist of cables, junction boxes, and RCP
motors.
3.9.2 Detection, Control, and Extinguishment
The licensee stated that Fire Zone 70A has a partial automatic fire
detection system installed that consists of ionization detectors
located over RCPs 23 and 24 but does not have an automatic fire
suppression system. The licensee also stated that the detection system
was designed and installed in accordance with NFPA 72D, 1975 Edition.
3.9.3 Preservation of Safe Shutdown Capability
The licensee stated that Fire Zone 70A has an approximate floor
area of 3,320 square feet and an approximate ceiling height of 25'-8''.
The licensee also stated that there is an oil collection system
provided for RCPs 23 and 24. The licensee stated that cable Y15-H50 for
valve 204B and cable Y17-H55 for valve 204A are located in this zone.
Valve 204A is an air-operated valve which allows charging pump flow to
an RCS hot leg. Valve 204B is an air-operated valve which allows
charging pump flow to an RCS cold leg. The licensee stated that cables
and components associated with redundant trains of normal
instrumentation required to support normal safe
[[Page 7193]]
shutdown operations are located in this zone. The normal safe shutdown
instrumentation potentially affected by fire includes:
SG wide range level: LT-417D, LT-427D, LT-437D, LT-447D
Pressurizer level: LT-459, LT-460, LT-461, LT-462
Source-range neutron monitoring: N-31, N-32
RCS loop hot and cold leg temperatures: TE-411 A/1, TE-
413, TE-422A/1, TE-423, TE-431A/1, TE-433, TE-440A/1, TE-443
3.9.4 OMAs Credited for a Fire in Fire Area H (Fire Zone 70A)
3.9.4.1 OMA 8--Align Charging Pump Makeup Path to RCS
It is possible that a fire in this zone could result in a loss of a
reliable charging makeup path to the RCS due to air-operated charging
system valves 204A and 204B spuriously closing. The licensee stated
that normal reactor coolant makeup to the RCS may be established via
hot leg injection through valve 204A or cold leg injection through
valve 204B and that in order to accomplish this, normal reactor coolant
makeup air-operated charging system valves 204A and 204B would need to
be failed open by de-energizing 125VDC control power in the CCR or by
closing the air supply isolation valve IA-501, which is outside the
containment building, to isolate instrument air.
Procedure 2-ONOP-FP-001 includes preemptive actions to establish
the charging makeup path by failing open charging injection valves 204A
and 204B. This is accomplished by removing DC control power to the
valves by pulling the control power fuses in the CCR or tripping
breakers 5 and 15 on 125 VDC DP 21 and 22, respectively. Procedure 2-
AOP-SSD-1 includes actions to close the air supply isolation valve IA-
501, and the loss of air pressure will cause valves 204A and 204B to
fail open.
If a fire were to occur and causes valves 204A and 204B to remain
closed, the licensee stated that OMA 8 is available to align
the charging pump makeup path to the RCS. If OMA 8 becomes
necessary, the licensee stated that they have assumed a 14-minute
diagnosis period and that the required time to perform the action is 14
minutes, which results in a total required time of 28 minutes while the
time available is 75 minutes, which provides 47 minutes of margin.
3.9.4.2 OMAs 9 and 10--Activate or Enable Alternate
Safe Shutdown System Pneumatic Instruments and Enable Alternate Safe
Shutdown System Source-Range Channel and Loop 21 and 22 hot and cold
leg Temperature Channels
In the event that a fire in Fire Area H disables redundant trains
of normal safe shutdown instrumentation identified in Section 3.9.3,
the licensee may make use of OMAs performed in a different fire area to
place in service Alternate Safe-Shutdown System instruments which have
been separated from the normal shutdown instruments in accordance with
III.G.2(f). The licensee also stated that in locations where normal and
alternate shutdown instrument cables are separated by less than 20
feet, the cables of the alternate shutdown instruments are protected by
a radiant energy shield as required to meet III.G.2(f). The Alternate
Safe Shutdown System instrument channels include:
RCP Loop 21 and 22 hot and cold leg temperature (TE-5139,
TE-5140, TE-5141, TE-5142),
SG 21 and 22 level (LT-5001, LT-5002),
Pressurizer level (LT-3101), pressurizer pressure (PT-
3105), and
Source range neutron monitoring (NE-5143)
The licensee stated that cables associated with Loop 21 and 22 hot
and cold leg temperature channels TE-5139, 5140, 5141, 5142, and
source-range channel NE-5143 are routed into containment through
penetration H20, and are protected with a radiant energy shield
throughout the containment annulus area, where they are in proximity to
cable trays or conduits containing the corresponding normal RCS loop
temperature channels. The licensee also stated that there are no cables
associated with the balance of the alternate SSD instruments (LT-5001,
LT-5002, PT-3105, and LT- 3101), since these channels utilize
pneumatically-operated transducers. The licensee stated that the
Alternate Safe Shutdown System pneumatic instrumentation can be
expected to remain operable despite fire-induced failure of the
redundant electrically-operated instrumentation, since the Alternate
Safe Shutdown System instruments do not utilize any electrical
components or cables.
In addition, the licensee stated that all four RCPs are equipped
with RCP lube oil collection systems which capture any leakage from
credible leak sites and transport it to collection tanks located
outside the bioshield wall in Fire Zone 77A.
In the event that redundant trains of normal shutdown
instrumentation are damaged by a fire, OMAs 9 and 10
are available to activate the following Alternate Safe Shutdown System
instruments:
Pneumatic instruments
[cir] SG level (LT-5001, LT-5002),
[cir] Pressurizer pressure (PT-3105), and
[cir] Pressurizer level (LT-3101)
Source-range channel (NE-5143), and
Loop 21 and 22 hot leg (Th) and cold leg (Tc) temperature
channels (TE-5139, TE-5140, TE-5141, TE-5142)
Procedure 2-AOP-SSD-1 includes actions to place these Alternate
Safe Shutdown System instruments in service. If OMAs 9 and
10 become necessary, the licensee stated that they have
assumed less than 1 minute for diagnosis, with the normal instruments
assumed to be failed at the start of the event, and that the required
time to perform the action is 13 minutes for the pneumatic instruments.
The shortest timeline is to monitor level in the SGs, which could
approach boil-dry conditions within 34 minutes. This results in 21
minutes of margin for the pneumatic instruments. The five electronic
instruments are then energized by the same operator who made the
pneumatic instruments operable, so it takes 24 minutes to put the
electronic instruments in service. However, the electronic instrument
readings are not needed until later in the scenario. This results in a
total required time of 13 minutes while the time available is 34
minutes, which provides 21 minutes of margin.
3.9.5 Conclusion for Fire Area H (Fire Zone 70A)
Given the low combustible fuel loading, the oil collection system
for the RCPs, automatic smoke detection system, large volume of the
space, and preemptive nature of the OMAs, it is unlikely that a fire
would occur and go undetected and not be extinguished in a reasonable
amount of time to ensure that at least one train of equipment necessary
for safe shutdown remains free of fire damage. In the unlikely event
that a fire does occur and causes damage that necessitates OMAs
8, 9, and 10, the actions are clear and
proceduralized with 47 minutes of margin for OMA 8 and 21
minutes of margin for OMAs 9 and 10, available to
provide assurance that safe shutdown capability will be maintained
following the postulated fire events. Therefore, the NRC staff finds
that there is adequate defense-in-depth provided for Fire Zone 70A and
that OMAs 8, 9, and 10 are acceptable for
the purpose of providing the level of
[[Page 7194]]
protection intended by the regulation, and that an exemption from
III.G.2 based on these OMAs is granted for Fire Zone 70A.
3.10 Fire Area H--Containment Building (Fire Zone 71A--21 and 22
Reactor Coolant Pump Area, Elevation 46'-0'')
3.10.1 Fire Prevention
The licensee stated that the fire loading in this area is low and
that the fixed combustibles in this zone consist of cable insulation,
RCP lube oil, and other miscellaneous combustibles and that transient
combustibles are administratively controlled. The licensee also stated
that the ignition sources in the area consist of cables, junction
boxes, RCP motors, and pumps.
3.10.2 Detection, Control, and Extinguishment
The licensee stated that Fire Zone 71A has a partial automatic fire
detection system installed that consists of ionization detectors
located over RCPs 21 and 22 but does not have an automatic fire
suppression system. The licensee also stated that the detection system
was designed and installed in accordance with NFPA 72D, 1975 Edition.
3.10.3 Preservation of Safe Shutdown Capability
The licensee stated that Fire Zone 71A has an approximate floor
area of 3,320 square feet and an approximate ceiling height of 25'8''.
The licensee also stated that there is an oil collection system
provided for RCPs 21 and 22. The licensee stated that cable Y15-H50 for
valve 204B and cable Y17-H55 for valve 204A are located in this zone.
Valve 204A is an air-operated valve which allows charging pump flow to
an RCS hot leg. Valve 204B is an air-operated valve which allows
charging pump flow to an RCS cold leg. As discussed in Section 3.0
above, the licensee did not demonstrate any separation between credited
and redundant trains of equipment.
3.10.4 OMAs Credited for a Fire in Fire Area H (Fire Zone 71A)
3.10.4.1 OMA 8--Align Charging Pump Makeup Path to RCS
As discussed in Section 3.9.4.1 above, if a fire were to occur and
causes valves 204A and 204B to remain closed, the licensee stated that
OMA 8 is available to align the charging pump makeup path to
the RCS. If OMA 8 becomes necessary, the licensee stated that
they have assumed a 14-minute diagnosis period and that the required
time to perform the action is 14 minutes, which results in a total
required time of 28 minutes while the time available is 75 minutes,
which provides 47 minutes of margin.
3.10.5 Conclusion for Fire Area H (Fire Zone 71A)
Given the low combustible fuel loading, the oil collection system
for the RCPs, automatic smoke detection system, large volume of the
space, and preemptive nature of OMA 8, it is unlikely that a
fire would occur and go undetected and not be extinguished in a
reasonable amount of time to ensure that at least one train of
equipment necessary for safe shutdown remains free of fire damage. In
the unlikely event that a fire does occur and causes damage that
necessitates OMA 8, the actions are clear and proceduralized
with 47 minutes of margin available to provide assurance that safe
shutdown capability will be maintained following the postulated fire
events. Therefore, the NRC staff finds that there is adequate defense-
in-depth provided for Fire Zone 71A and that OMA 8 is
acceptable for the purpose of providing the level of protection
intended by the regulation, and that an exemption from III.G.2 based on
OMA 8 is granted for Fire Zone 71A.
3.11 Fire Area H--Containment Building (Fire Zone 72A--Outer Annulus,
Elevation 46'0'')
3.11.1 Fire Prevention
The licensee stated that the fire loading in this area is low and
that the fixed combustibles in this zone consist of cable insulation
and that transient combustibles are administratively controlled. The
licensee also stated that the ignition sources in the area consist of
cables.
3.11.2 Detection, Control, and Extinguishment
The licensee stated that Fire Zone 72A does not have an automatic
fire detection or automatic suppression system installed.
3.11.3 Preservation of Safe Shutdown Capability
The licensee stated that Fire Zone 72A has an approximate floor
area of 1,100 square feet and an approximate ceiling height of 22'0''.
The licensee stated that cables for valve 204B and valve 204A are
located in this zone. Valve 204A is an air-operated valve which allows
charging pump flow to an RCS hot leg. Valve 204B is an air-operated
valve which allows charging pump flow to an RCS cold leg. As discussed
in Section 3.0 above, the licensee did not demonstrate any separation
between credited and redundant trains of equipment.
3.11.4 OMAs Credited for a Fire in Fire Area H (Fire Zone 72A)
3.11.4.1 OMA 8--Align Charging Pump Makeup Path to RCS
As stated in Section 3.9.4.1 above, if a fire were to occur and
causes valves 204A and 204B to remain closed, the licensee stated that
OMA 8 is available to align the charging pump makeup path to
the RCS. If OMA 8 becomes necessary, the licensee stated that
they have assumed a 14-minute diagnosis period and that the required
time to perform the action is 14 minutes, which results in a total
required time of 28 minutes while the time available is 75 minutes,
which provides 47 minutes of margin.
3.11.5 Conclusion for Fire Area H (Fire Zone 72A)
Since the licensee described postulated fire scenarios and Fire
Zone 72A lacks an automatic fire detection system or automatic
suppression system, and any discernable separation between the credited
and redundant equipment in the area, it is credible that a fire would
not be detected and extinguished in a reasonable amount of time to
ensure that at least one train of equipment remains free of fire damage
following a fire event. Although there is 47 minutes of margin
available for OMA 8, Fire Zone 72A still lacks adequate
defense-in-depth. Therefore, the staff finds that Fire Zone 72A's
defense-in-depth is insufficient to demonstrate reasonable assurance
that safe shutdown can be achieved. As such, OMA 8 is
unacceptable for the purpose of providing the level of protection
intended by the regulation and an exemption from III.G.2 based on OMA
8 cannot be granted for Fire Zone 72A.
3.12 Fire Area H--Containment Building (Fire Zone 75A--Outer Annulus,
Elevation 46'-0'')
3.12.1 Fire Prevention
The licensee stated that the fire loading in this area is moderate
and that the fixed combustibles in this zone consist of cable
insulation and that transient combustibles are administratively
controlled. The licensee also stated that the ignition sources in the
area consist of cables and junction boxes.
3.12.2 Detection, Control, and Extinguishment
The licensee stated that Fire Zone 75A does not have an automatic
fire
[[Page 7195]]
detection or automatic suppression system installed.
3.12.3 Preservation of Safe Shutdown Capability
The licensee stated that Fire Zone 75A has an approximate floor
area of 1,100 square feet and an approximate ceiling height of 22'-0''.
The licensee also stated that the Alternate Safe Shutdown System
instrumentation cabling is protected with a radiant energy shield. The
licensee stated that cables and components associated with redundant
trains of normal instrumentation required to support normal safe
shutdown operations are located in this zone. The normal safe shutdown
instrumentation potentially affected by fire in Fire Area H includes:
SG wide range level: LT-417D, LT-427D, LT-437D, LT-447D
Pressurizer level: LT-459, LT-460, LT-461, LT-462
Source-range neutron monitoring: N-31, N-32
RCS loop hot and cold leg temperatures: TE-411 A/1, TE-
413, TE-422A/1, TE-423, TE-431A/1, TE-433, TE-440A/1, TE-443
The licensee stated that cable Y15-H50 for valve 204B and cable
Y17-H55 for valve 204A are located in this zone. As discussed in
Section 3.0 above, the licensee did not demonstrate any separation
between credited and redundant trains of equipment.
3.12.4 OMAs Credited for a Fire in Fire Area H (Fire Zone 75A)
3.12.4.1 OMA 8--Align Charging Pump Makeup Path to RCS
As stated in Section 3.9.4.1 above, if a fire were to occur and
causes valves 204A and 204B to remain closed, the licensee stated that
OMA 8 is available to align the charging pump makeup path to
the RCS. If OMA 8 becomes necessary, the licensee stated that
they have assumed a 14-minute diagnosis period and that the required
time to perform the action is 14 minutes, which results in a total
required time of 28 minutes while the time available is 75 minutes,
which provides 47 minutes of margin.
3.12.4.2 OMAs 9 and 10--Activate or Enable Alternate
Safe Shutdown System Pneumatic Instruments and Enable Alternate Safe
Shutdown System Source-Range Channel and Loop 21 and 22 Hot and Cold
Leg Temperature Channels
As discussed in Section 3.9.4.2 above, in the event that a fire in
Fire Area H disables redundant trains of normal safe shutdown
instrumentation identified in Section 3.9.3, the licensee may make use
of OMAs performed in a different fire area to place in service
Alternate Safe Shutdown System instruments which have been separated
from the normal shutdown instruments in accordance with III.G.2(f). The
licensee also stated that in locations where normal and alternate
shutdown instrument cables are separated by less than 20 feet, the
cables of the alternate shutdown instruments are protected by a radiant
energy shield as required to meet III.G.2(f).
If OMAs 9 and 10 become necessary, the licensee
stated that they have assumed less than 1 minute for diagnosis, with
the normal instruments assumed to be failed at the start of the event,
and that the required time to perform the action is 13 minutes for the
pneumatic instruments. The shortest timeline is to monitor level in the
SGs, which could approach boil-dry conditions within 34 minutes. This
results in 21 minutes of margin for the pneumatic instruments. The five
electronic instruments are then energized by the same operator who made
the pneumatic instruments operable, so it takes 24 minutes to put the
electronic instruments in service. However, the electronic instrument
readings are not needed until later in the scenario. This results in a
total required time of 13 minutes while the time available is 34
minutes, which provides 21 minutes of margin.
3.12.5 Conclusion for Fire Area H (Fire Zone 75A)
Since the licensee described postulated fire scenarios and Fire
Zone 75A has a moderate combustible fuel loading, lacks an automatic
fire detection system or automatic suppression system, and any
discernable separation between the credited and redundant equipment in
the area, it is credible that a fire would not be detected and
extinguished in a reasonable amount of time to ensure that at least one
train of equipment remains free of fire damage following a fire event.
Although there is 47 minutes of margin available for OMA 8 and
21 minutes of margin available for OMAs 9 and 10,
Fire Zone 75A still lacks adequate defense-in-depth. Therefore, the
staff finds that the defense-in-depth is insufficient to demonstrate
reasonable assurance that safe shutdown can be achieved for a fire in
Fire Zone 75A and that OMAs 8, 9, and 10 are
unacceptable for the purpose of providing the level of protection
intended by the regulation and that an exemption from III.G.2 based on
these OMAs cannot be granted for Fire Zone 75A.
3.13 Fire Area H--Containment Building (Fire Zone 77A--Outer Annulus)
3.13.1 Fire Prevention
The licensee stated that the fire loading in this area is low and
that the fixed combustibles in this zone consist of cable insulation
and that transient combustibles are administratively controlled. The
licensee also stated that the ignition sources in the area consist of
cables and junction boxes.
3.13.2 Detection, Control, and Extinguishment
The licensee stated that Fire Zone 77A does not have an automatic
fire detection or automatic suppression system installed.
3.13.3 Preservation of Safe Shutdown Capability
The licensee stated that Fire Zone 77A has an approximate floor
area of 950 square feet and an approximate ceiling height of 22'-0''.
The licensee stated that cables and components associated with
redundant trains of normal instrumentation required to support normal
safe shutdown operations are located in this zone. The normal safe
shutdown instrumentation potentially affected by fire in Fire Area H
includes:
SG wide range level: LT-417D, LT-427D, LT-437D, LT-447D
Pressurizer level: LT-459, LT-460, LT-461, LT-462
Source-range neutron monitoring: N-31, N-32
RCS loop hot and cold leg temperatures: TE-411 A/1, TE-
413, TE-422A/1, TE-423, TE-431A/1, TE-433, TE-440A/1, TE-443
The licensee stated that cable Y15-H50 for valve 204B and cable
Y17-H55 for valve 204A are located in this zone. As discussed in
Section 3.0 above, the licensee did not demonstrate any separation
between credited and redundant trains of equipment.
3.13.4 OMAs Credited for a Fire in Fire Area H (Fire Zone 77A)
3.13.4.1 OMA 8--Align Charging Pump Makeup Path to RCS
As stated in Section 3.9.4.1 above, if a fire were to occur and
causes valves 204A and 204B to remain closed, the licensee stated that
OMA 8 is available to align the charging pump makeup path to
the RCS. If OMA 8 becomes necessary, the licensee stated that
they have assumed a 14-minute diagnosis period and that the required
time to perform the action is 14 minutes, which results in a total
required time of 28 minutes while the time available is 75
[[Page 7196]]
minutes, which provides 47 minutes of margin.
3.13.4.2 OMAs 9 and 10--Activate or Enable Alternate
Safe Shutdown System Pneumatic Instruments and Enable Alternate Safe
Shutdown System Source-Range Channel and Loop 21 and 22 Hot and Cold
Leg Temperature Channels
As discussed in Section 3.9.4.2 above, in the event that a fire in
Fire Area H disables redundant trains of normal safe shutdown
instrumentation identified in Section 3.9.3, the licensee may make use
of OMAs performed in a different fire area to place in service
Alternate Safe-Shutdown System instruments which have been separated
from the normal shutdown instruments in accordance with III.G.2(f). The
licensee also stated that in locations where normal and alternate
shutdown instrument cables are separated by less than 20 feet, the
cables of the alternate shutdown instruments are protected by a radiant
energy shield as required to meet III.G.2(f).
If OMAs 9 and 10 become necessary, the licensee
stated that they have assumed less than 1 minute for diagnosis, with
the normal instruments assumed to be failed at the start of the event,
and that the required time to perform the action is 13 minutes for the
pneumatic instruments. The shortest timeline is to monitor level in the
SGs, which could approach boil-dry conditions within 34 minutes. This
results in 21 minutes of margin for the pneumatic instruments. The five
electronic instruments are then energized by the same operator who made
the pneumatic instruments operable, so it takes 24 minutes to put the
electronic instruments in service. However, the electronic instrument
readings are not needed until later in the scenario. This results in a
total required time of 13 minutes while the time available is 34
minutes, which provides 21 minutes of margin.
3.13.5 Conclusion for Fire Area H (Fire Zone 77A)
Since the licensee described postulated fire scenarios and Fire
Zone 77A lacks an automatic fire detection or automatic suppression
system, and any discernable separation between the credited and
redundant equipment in the area, it is credible that a fire would not
be detected and extinguished in a reasonable amount of time to ensure
that at least one train of equipment remains free of fire damage
following a fire event. Although there is 47 minutes of margin
available for OMA 8 and 21 minutes of margin available for
OMAs 9 and 10, Fire Zone 77A still lacks adequate
defense-in-depth. Therefore, the staff finds that the defense-in-depth
is insufficient to demonstrate reasonable assurance that safe shutdown
can be achieved for a fire in Fire Zone 77A and that OMAs 8,
9, and 10 are unacceptable for the purpose of
providing the level of protection intended by the regulation and that
an exemption from III.G.2 based on these OMAs cannot be granted for
Fire Zone 77A.
3.14 Fire Area H--Containment Building (Fire Zone 84A-22 Containment
Fan Cooler Unit Area, Elevation 68'-0'')
3.14.1 Fire Prevention
The licensee stated that the fire loading in this area is low and
that the fixed combustibles in this zone consist of cable insulation
and that transient combustibles are administratively controlled. The
licensee also stated that the ignition sources in the area consist of
cables.
3.14.2 Detection, Control, and Extinguishment
The licensee stated that Fire Zone 84A does not have an automatic
fire detection or automatic suppression system installed.
3.14.3 Preservation of Safe Shutdown Capability
The licensee stated that Fire Zone 84A has an approximate floor
area of 910 square feet and an approximate ceiling height of 27'-0''.
The licensee stated that cable Y15-H50 for valve 204B and cable Y17-H55
for valve 204A are located in this zone. As discussed in Section 3.0
above, the licensee could not demonstrate any separation between
credited and redundant trains of equipment.
3.14.4 OMAs Credited for a Fire in Fire Area H (Fire Zone 84A)
3.14.4.1 OMA 8--Align Charging Pump Makeup Path to RCS
As stated in Section 3.9.4.1 above, if a fire were to occur and
causes valves 204A and 204B to remain closed, the licensee stated that
OMA 8 is available to align the charging pump makeup path to
the RCS. If OMA 8 becomes necessary, the licensee stated that
they have assumed a 14-minute diagnosis period and that the required
time to perform the action is 14 minutes, which results in a total
required time of 28 minutes while the time available is 75 minutes,
which provides 47 minutes of margin.
3.14.5 Conclusion for Fire Area H (Fire Zone 84A)
Since the licensee described postulated fire scenarios and Fire
Zone 84A lacks an automatic fire detection or automatic suppression
system, and any discernable separation between the credited and
redundant equipment in the area, it is credible that a fire would not
be detected and extinguished in a reasonable amount of time to ensure
that at least one train of equipment remains free of fire damage
following a fire event. Although there is 47 minutes of margin
available for OMA 8, Fire Zone 84A still lacks adequate
defense-in-depth. Therefore, the staff finds that the defense-in-depth
is insufficient to demonstrate reasonable assurance that safe shutdown
can be achieved for a fire in Fire Zone 84A and that OMA 8 is
unacceptable for the purpose of providing the level of protection
intended by the regulation and that an exemption from III.G.2 based on
this OMA cannot be granted for Fire Zone 84A.
3.15 Fire Area H--Containment Building (Fire Zone 85A--Incore Detector
Drive Area, Elevation 68'-0'')
3.15.1 Fire Prevention
The licensee stated that the fire loading in this area is low and
that the fixed combustibles in this zone consist of cable insulation
and that transient combustibles are administratively controlled.
3.15.2 Detection, Control, and Extinguishment
The licensee stated that Fire Zone 85A does not have an automatic
fire detection or automatic suppression system installed.
3.15.3 Preservation of Safe Shutdown Capability
The licensee stated that Fire Zone 85A has an approximate floor
area of 560 square feet and an approximate ceiling height of 27'-0''.
The licensee stated that cable Y15-H50 for valve 204B and cable Y17-H55
for valve 204A are located in this zone. As discussed in Section 3.0
above, the licensee could not demonstrate any separation between
credited and redundant trains of equipment.
3.15.4 OMAs Credited for a Fire in Fire Area H (Fire Zone 85A)
3.15.4.1 OMA 8--Align Charging Pump Makeup Path to RCS
As stated in Section 3.9.4.1 above, if a fire were to occur and
causes valves 204A and 204B to remain closed, the licensee stated that
OMA 8 is available
[[Page 7197]]
to align the charging pump makeup path to the RCS. If OMA 8
becomes necessary, the licensee stated that they have assumed a 14-
minute diagnosis period and that the required time to perform the
action is 14 minutes, which results in a total required time of 28
minutes while the time available is 75 minutes, which provides 47
minutes of margin.
3.15.5 Conclusion for Fire Area H (Fire Zone 85A)
Since the licensee stated that a fire in this zone could result in
a loss of a reliable charging makeup path to the RCS and Fire Zone 85A
lacks an automatic fire detection or suppression system, and any
discernable separation between the credited and redundant equipment in
the area, it is credible that a fire would not be detected and
extinguished in a reasonable amount of time to ensure that at least one
train of equipment remains free of fire damage following a fire event.
Although there is 47 minutes of margin available for OMA 8,
Fire Zone 85A still lacks adequate defense-in-depth. Therefore, the
staff finds that the defense-in-depth is insufficient to demonstrate
reasonable assurance that safe shutdown can be achieved for a fire in
Fire Zone 85A and that OMA 8 is unacceptable for the purpose
of providing the level of protection intended by the regulation and
that an exemption from III.G.2 based on this OMA cannot be granted for
Fire Zone 85A.
3.16 Fire Area H--Containment Building (Fire Zone 87A--Outer Annulus,
Elevation 46'-0'')
3.16.1 Fire Prevention
The licensee stated that the fire loading in this area is low and
that the fixed combustibles in this zone consist of MCCs and instrument
racks and that transient combustibles are administratively controlled.
The licensee also stated that the ignition sources in the area consist
of MCCs.
3.16.2 Detection, Control, and Extinguishment
The licensee stated that Fire Zone 87A does not have an automatic
fire detection or automatic suppression system installed.
3.16.3 Preservation of Safe Shutdown Capability
The licensee stated that Fire Zone 87A has an approximate floor
area of 434 square feet and an approximate ceiling height of 22'-0'',
which is partially open to the containment dome at the 95'-0''
elevation. The licensee stated that cables and components associated
with redundant trains of normal instrumentation required to support
normal safe shutdown operations are located in this zone. The normal
safe shutdown instrumentation potentially affected by fire in Fire Area
H includes:
SG wide range level: LT-417D, LT-427D, LT-437D, LT-447D
Pressurizer level: LT-459, LT-460, LT-461, LT-462
Source-range neutron monitoring: N-31, N-32
RCS loop hot and cold leg temperatures: TE-411 A/1, TE-
413, TE-422A/1, TE-423, TE-431A/1, TE-433, TE-440A/1, TE-443
The licensee stated that cable Y15-H50 for valve 204B and cable Y17-H55
for valve 204A are located in this zone. As discussed in Section 3.0
above, the licensee did not demonstrate any separation between credited
and redundant trains of equipment.
3.16.4 OMAs Credited for a Fire in Fire Area H (Fire Zone 87A)
3.16.4.1 OMA 8--Align Charging Pump Makeup Path to RCS
As stated in Section 3.9.4.1 above, if a fire were to occur and
causes valves 204A and 204B to remain closed, the licensee stated that
OMA 8 is available to align the charging pump makeup path to
the RCS. If OMA 8 becomes necessary, the licensee stated that
they have assumed a 14-minute diagnosis period and that the required
time to perform the action is 14 minutes, which results in a total
required time of 28 minutes while the time available is 75 minutes,
which provides 47 minutes of margin.
3.16.4.2 OMAs 9 and 10--Activate or Enable Alternate
Safe Shutdown System Pneumatic Instruments and Enable Alternate Safe
Shutdown System Source-Range Channel and Loop 21 and 22 Hot and Cold
Leg Temperature Channels
As discussed in Section 3.9.4.2 above, in the event that a fire in
Fire Area H disables redundant trains of normal safe shutdown
instrumentation identified in Section 3.9.3, the licensee may make use
of OMAs performed in a different fire area to place in service
Alternate Safe Shutdown System instruments which have been separated
from the normal shutdown instruments in accordance with III.G.2(f). The
licensee also stated that in locations where normal and alternate
shutdown instrument cables are separated by less than 20 feet, the
cables of the alternate shutdown instruments are protected by a radiant
energy shield as required to meet III.G.2(f).
If OMAs 9 and 10 become necessary, the licensee
stated that they have assumed less than 1 minute for diagnosis, with
the normal instruments assumed to be failed at the start of the event,
and that the required time to perform the action is 13 minutes for the
pneumatic instruments. The shortest timeline is to monitor level in the
SGs, which could approach boil-dry conditions within 34 minutes. This
results in 21 minutes of margin for the pneumatic instruments. The five
electronic instruments are then energized by the same operator who made
the pneumatic instruments operable, so it takes 24 minutes to put the
electronic instruments in service. However, the electronic instrument
readings are not needed until later in the scenario. This results in a
total required time of 13 minutes while the time available is 34
minutes, which provides 21 minutes of margin.
3.16.5 Conclusion for Fire Area H (Fire Zone 87A)
Since the licensee described postulated fire scenarios and Fire
Zone 87A lacks an automatic fire detection or suppression system, and
any discernable separation between the credited and redundant equipment
in the area, it is credible that a fire would not be detected and
extinguished in a reasonable amount of time to ensure that at least one
train of equipment remains free of fire damage following a fire event.
Although there is 47 minutes of margin available for OMA 8 and
21 minutes of margin available for OMAs 9 and 10,
Fire Zone 87A still lacks adequate defense-in-depth. Therefore, the
staff finds that the defense-in-depth is insufficient to demonstrate
reasonable assurance that safe shutdown can be achieved for a fire in
Fire Zone 87A and that OMAs 8, 9, and 10 are
unacceptable for the purpose of providing the level of protection
intended by the regulation and that an exemption from III.G.2 based on
these OMAs cannot be granted for Fire Zone 87A.
3.17 Fire Area J--Unit 1 Control Room, Turbine Building, Superheater
Building, Nuclear Service Building, Chemical Systems Building,
Administration Building, Screenwell House, and Unit 2 Turbine Building
(Fire Zone 17--Turbine Oil Reservoir Area, Elevation 15'-0'' Unit 2
Turbine Building)
3.17.1 Fire Prevention
The licensee stated that the fire loading in this area is high and
that the
[[Page 7198]]
fixed combustibles in this zone consist of lube oil, fuel oil, and
welding leads and that transient combustibles consist of trash,
cardboard, lube oil, fiberglass, rubber, wood, and plastic. The
licensee also stated that the ignition sources in the area consist of
electrical cabinets. The licensee further stated that since Fire Area J
does not contain safety-related structures, systems or components, it
is not subject to the explicit transient combustible controls of
procedure EN-DC-161. However, operator rounds performed each shift
provide for the monitoring of combustibles that could challenge fire
safety. In addition, the licensee stated that procedures OAP-017,
``Plant Surveillance and Operator Rounds'' and EN-MA-132,
``Housekeeping'' include guidance for monitoring general area
cleanliness as well as monitoring for accumulations of combustibles.
3.17.2 Detection, Control, and Extinguishment
The licensee stated that Fire Zone 17 has an automatic thermal fire
detection system installed throughout the zone and an automatic aqueous
foaming foam spray system installed at the turbine lube oil reservoir.
The licensee also stated that the detection system was designed and
installed in accordance with NFPA 72D, 1967 Edition and the fire
suppression system was designed and installed in accordance with NFPA
16, 1968 Edition.
3.17.3 Preservation of Safe Shutdown Capability
The licensee stated that Fire Zone 17 has an approximate floor area
of 968 square feet and an approximate ceiling height of 37'-0''. The
licensee stated that cable JC2-YA9, which is associated with Buses 5A
and 6A, is routed through Fire Zones 17, 47A, and 50A and that ignition
sources in the zone located less than 20 feet horizontally from cable
JC2-YA9 consists of electrical cabinets, motors, and MCCs. According to
the licensee, the electrical cabinets are separated from the cable by
approximately 3.8 feet horizontally and 1.9 feet vertically or greater
and six motors are located above the cable routing separated from the
cable by approximately 2.1 feet horizontally or greater. The licensee
also stated that the turbine lube oil reservoir is located in Fire Zone
17. As discussed in Section 3.0 above, the licensee could not
demonstrate any separation between credited and redundant trains of
equipment.
3.17.4 OMAs Credited for a Fire in Fire Area J (Fire Zone 17)
3.17.4.1 OMA 11--Trip Breakers 52/5A and 52-SAC on Bus 5A and
52/6A and 52/TAO at Bus 6A and Remove Control Power Fuses
The licensee stated that offsite power is the preferred lineup for
supplying the 480V loads on Buses 2A, 3A, 5A, and 6A. In the event that
offsite power is not available due to fire, the licensee stated that
the Emergency Diesel Generators (EDGs) are credited to supply 480V
loads on Buses 2A, 3A, 5A, and 6A. The licensee also stated that a fire
in Fire Zone 17 which damages certain cables associated with 480V Buses
5A and/or 6A could prevent loading of Buses 5 and 6 from the EDGs, and
thereby, result in a loss of 480V power from the affected bus(es).
Since a fire in Fire Zone 17 may impact the availability of offsite
power, the licensee stated that they assume offsite power is
unavailable at the start of the fire event.
In the event that a fire occurs and damages the cables identified
above, the licensee stated that OMA 11 is available to restore
or maintain power by tripping breakers 52/5A and 52-SAC on Bus 5A and
Breakers 52/6A and 52/TAO at Bus 6A in the 480V Switchgear Room (Fire
Area A) and removing their control power fuses. The licensee stated
that loss of power to the affected buses is detected by loss of
indication in the CCR. Loss of power to Bus 5A or Bus 6A causes
operators to immediately enter procedure 2-AOP-480V-1. The procedure
directs operators to locally inspect the switchgear, at which time any
remaining untripped breakers (i.e., 52/5A, 52-SAC, 52/6A, 52/TAO) would
be noted and locally tripped as necessary. If OMA 11 becomes
necessary, the licensee stated that they have assumed that a loss of
offsite power occurs at the beginning of the fire event and that the
required time to perform the action is 10 minutes while the time
available is 60 minutes, which provides 50 minutes of margin. The NRC
staff finds that OMA 11 has acceptable margin for all fire
zones in Fire Area J.
3.17.5 Conclusion for a Fire in Fire Area J (Fire Zone 17)
Given the fire detection system, automatic fire suppression system,
and large volume of the space, it is unlikely that a fire would occur
and go undetected and not be extinguished in a reasonable amount of
time to ensure that at least one train of equipment necessary for safe
shutdown remains free of fire damage. In the unlikely event that a fire
does occur and causes damage that necessitates OMA 11, the
action is clear and proceduralized with 50 minutes of margin available
to provide assurance that safe shutdown capability will be maintained
following the postulated fire events. Therefore, the NRC staff finds
that there is adequate defense-in-depth provided for Fire Zone 17 and
that OMA 11 is acceptable for the purpose of providing the
level of protection intended by the regulation, and that an exemption
from III.G.2 based on OMA 11 is granted for Fire Zone 17.
3.18 Fire Area J--Unit 1 Control Room, Turbine Building, Superheater
Building, Nuclear Service Building, Chemical Systems Building,
Administration Building, Screenwell House, and Unit 2 Turbine Building
(Fire Zone 19--Station Air Compressor Area, Elevation 15'-0'' Unit 2
Turbine Building)
3.18.1 Fire Prevention
The licensee stated that the fire loading in this zone is low and
that the primary fixed combustible in this zone is lube oil, which is
contained in the turbine lube oil piping system, and that transient
combustibles consist of trash, cleaning rags, lube oil, and paint. The
licensee also stated that the ignition sources in the area consist of a
motor, a compressor, and an electrical cabinet. The licensee further
stated that since Fire Area J does not contain safety-related
structures, systems or components, it is not subject to the explicit
transient combustible controls of procedure EN-DC-161. However,
operator rounds performed each shift provide for the monitoring of
combustibles that could challenge fire safety. In addition, the
licensee stated that procedures OAP-017, ``Plant Surveillance and
Operator Rounds'' and EN-MA-132, ``Housekeeping'' include guidance for
monitoring general area cleanliness as well as monitoring for
accumulations of combustibles.
3.18.2 Detection, Control, and Extinguishment
The licensee stated that Fire Zone 19 does not have a fire
detection or automatic fire suppression system installed.
3.18.3 Preservation of Safe Shutdown Capability
The licensee stated that Fire Zone 19 has an approximate floor area
of 798 square feet and an approximate ceiling height of 21'-0''. The
licensee stated that a fire in Fire Area J which damages certain cables
associated with 480V Buses 5A and/or 6A could prevent loading of Buses
5A and 6A from the EDGs, and thereby, result in a loss of
[[Page 7199]]
480VAC power from the affected bus(es). According to the licensee,
cables associated with Buses 5A and 6A are located in this fire zone.
The licensee stated that cable AG5-XA5, which is associated with Bus
5A, is located in Fire Zone 19. The licensee also stated that the
ignition sources in the zone located less than 20 feet horizontally
from cable AG5-XA5 consist of seven electrical cabinets, a 150kVA dry
transformer, three motors, and an MCC. According to the licensee, three
electrical cabinets are located under the cable separated by
approximately 3 feet vertically or greater, the remaining four
electrical cabinets are separated from the cable by approximately 2
feet horizontally or greater, the 150 kVA dry transformer is separated
from the cable by approximately 1.6 feet horizontally and 6.7 feet
vertically, the motors are separated from the cable by approximately
4.6 feet horizontally or greater, and the MCC is separated from the
cable by approximately 7.5 feet horizontally.
The licensee stated that cables PC9-XA5/1 and PC9-XA5/2, which are
associated with Bus 5A, are routed between two junction boxes in Fire
Zone 19 for approximately 2 feet. The licensee also stated that the
ignition sources in the zones located less than 20 feet horizontally
from the cable consist of three motors, which are all separated from
the cables by approximately 4.6 feet horizontally or greater. The
licensee also stated that cable XA5-WU9, associated with Bus 5A, is
routed in Fire Zone 19 from east to west terminating at the Station Air
Compressor. The licensee stated that the ignition sources in the zone
located less than 20 feet horizontally from the cable consist of two
motors, which are separated from the cable by approximately 4.6 feet
horizontally or greater. As discussed in Section 3.0 above, the
licensee could not demonstrate any separation between credited and
redundant trains of equipment.
3.18.4 OMAs Credited for a Fire in Fire Area J (Fire Zone 19)
3.18.4.1 OMA 11--Trip Breakers 52/5A and 52-SAC on bus 5A and
52/6A and 52/TAO at bus 6A and Remove Control Power Fuses.
OMA 11 was evaluated in Section 3.17.4.1 above. As stated
in Section 3.17.4.1, OMA 11 has acceptable margin for all fire
zones in Fire Area J.
3.18.5 Conclusion for Fire Area J (Fire Zone 19)
Since the licensee described postulated fire scenarios and Fire
Zone 19 lacks an automatic fire detection or automatic fire suppression
system, and any discernable separation between the credited and
redundant equipment in the area, it is possible that a fire would not
be detected and extinguished in a reasonable amount of time to ensure
that at least one train of equipment remains free of fire damage
following a fire event. Although there is 50 minutes of margin
available for OMA 11, Fire Zone 19 still lacks adequate
defense-in-depth. Therefore, the staff finds that the defense-in-depth
is insufficient to demonstrate reasonable assurance that safe shutdown
can be achieved for a fire in Fire Zone 19 and that OMA 11 is
unacceptable for the purpose of providing the level of protection
intended by the regulation. Therefore, the NRC staff finds that an
exemption from III.G.2 based on this OMA cannot be granted for Fire
Zone 19.
3.19 Fire Area J--Unit 1 Control Room, Turbine Building, Superheater
Building, Nuclear Service Building, Chemical Systems Building,
Administration Building, Screenwell House, and Unit 2 Turbine Building
(Fire Zone 25--23 Battery Room, Elevation 33'-0'' of the Unit 1
Superheater Building)
3.19.1 Fire Prevention
The licensee stated that the fire loading in this zone is low and
that the primary fixed combustibles in this zone are batteries and
cable insulation and that transient combustibles are administratively
controlled. The licensee also stated that the ignition sources in the
area consist of batteries and electrical cabinets. The licensee further
stated that since Fire Area J does not contain safety-related
structures, systems or components, it is not subject to the explicit
transient combustible controls of procedure EN-DC-161. However,
operator rounds performed each shift provide for the monitoring of
combustibles that could present an unacceptable fire safety challenge.
In addition, the licensee stated that procedures OAP-017, ``Plant
Surveillance and Operator Rounds'' and EN-MA-132, ``Housekeeping''
include guidance for monitoring general area cleanliness as well as
monitoring for accumulations of combustibles.
3.19.2 Detection, Control, and Extinguishment
The licensee stated that Fire Zone 25 does not have a fire
detection or automatic fire suppression system installed.
3.19.3 Preservation of Safe Shutdown Capability
The licensee stated that Fire Zone 25 has an approximate floor area
of 92 square feet and an approximate ceiling height of 10'-0''. The
licensee stated that cables EDB8-EPB3, EGA9-EDB8/4, and EGA9-EDB8/5 are
routed through Fire Zone 25 in rigid steel conduit and that since
cables EGA9-EDB8/4 and EGA9-EDB8/5 originate inside the battery room at
the batteries, there is no separation between the cables and the
batteries. The licensee also stated that ignition sources in the zone
located less than 20 feet horizontally from cable EDB8-EPB3 consist of
an MCC, a 45kVA dry transformer, and two electrical cabinets. According
to the licensee, the MCC is separated from the cable by approximately
18.5 feet horizontally, the transformer is separated from the cable by
approximately 13.6 feet horizontally, one electrical cabinet is
separated from the cable by approximately 12.8 feet horizontally, and
the second electrical cabinet is separated from the cable by
approximately 5.5 feet horizontally. As discussed in Section 3.0 above,
the licensee could not demonstrate any separation between credited and
redundant trains of equipment.
3.19.4 OMAs Credited for a Fire in Fire Area J (Fire Zone 25)
3.19.4.1 OMA 12--Transfer Instrument Buses 23 and 23A to
Emergency Power Source
The licensee stated that instrument buses 23 and 23A could
experience a loss of their normal power source (125 VDC power panel 23)
as a result of fire in Fire Zone 25. If this were to occur, the
licensee stated that OMA 12 is available to swap Instrument
Buses 23 and 23A to their backup power source (MCC-29A). If OMA
12 becomes necessary, the licensee stated that they have
assumed a 5.5-minute diagnosis period and that the required time to
perform the action is 2 minutes while the time available is 30 minutes,
which provides 22.5 minutes of margin.
3.19.5 Conclusion for Fire Area J (Fire Zone 25)
Since the licensee described postulated fire scenarios and Fire
Zone 25 lacks an automatic fire detection or automatic fire suppression
system, and any discernable separation between the credited and
redundant equipment in the area, it is possible that a fire would not
be detected and extinguished in a reasonable amount of time to ensure
[[Page 7200]]
that at least one train of equipment remains free of fire damage
following a fire event. Although there is 22.5 minutes of margin
available for OMA 12, Fire Zone 25 still lacks adequate
defense-in-depth. Therefore, the NRC staff finds that the defense-in-
depth is insufficient to demonstrate reasonable assurance that safe
shutdown can be achieved for a fire in Fire Zone 25 and that OMA
12 is unacceptable for the purpose of providing the level of
protection intended by the regulation. Therefore, the NRC staff finds
that an exemption from III.G.2 based on OMA 12 cannot be
granted for Fire Zone 25.
3.20 Fire Area J--Unit 1 Control Room, Turbine Building, Superheater
Building, Nuclear Service Building, Chemical Systems Building,
Administration Building, Screenwell House, and Unit 2 Turbine Building
(Fire Zone 39A--Mezzanine Floor, Elevation 36'-9'' Unit 2 Turbine
Building)
3.20.1 Fire Prevention
The licensee stated that the fire loading in this zone is moderate
and that the fixed combustibles in this zone consist of cable
insulation, plastic, and cellulose and that transient combustibles in
this zone consist of trash, wood, and lube oil. The licensee also
stated that the ignition sources in this zone consist of cables,
junction boxes, electrical cabinets, and motors. The licensee further
stated that since Fire Area J does not contain safety-related
structures, systems or components, it is not subject to the explicit
transient combustible controls of procedure EN-DC-161. However,
operator rounds performed each shift provide for the monitoring of
combustibles that could present an unacceptable fire safety challenge.
In addition, the licensee stated that procedures OAP-017 (Plant
Surveillance and Operator Rounds) and EN-MA-132 (Housekeeping) include
guidance for monitoring general area cleanliness as well as monitoring
for accumulations of combustibles.
3.20.2 Detection, Control, and Extinguishment
The licensee stated that Fire Zone 39A does not have a fire
detection or automatic fire suppression system installed.
3.20.3 Preservation of Safe Shutdown Capability
The licensee stated that Fire Zone 39A has an approximate floor
area of 7,592 square feet and an approximate ceiling height of 16'-0''.
The licensee stated that cable AG5-XA5, which is associated with
instrument buses 23 and 23A and buses 5A and 6A, is located in Fire
Zone 39A. The licensee also stated that the ignition sources in the
zone located less than 20 feet horizontally from cable AG5-XA5 consist
of seven electrical cabinets, a 150 kVA dry transformer, three motors,
and an MCC. According to the licensee, three electrical cabinets are
located under the cable separated by approximately 3 feet vertically or
greater, the remaining four electrical cabinets are separated from the
cable by approximately 2 feet horizontally or greater, the 150 kVA dry
transformer is separated from the cable by approximately 1.6 feet
horizontally and 6.7 feet vertically, the motors are separated from the
cable by approximately 4.6 feet horizontally or greater, and the MCC is
separated from the cable by approximately 7.5 feet horizontally. As
discussed in Section 3.0 above, the licensee could not demonstrate any
separation between credited and redundant trains of equipment.
3.20.4 OMAs Credited for a Fire in Fire Area J (Fire Zone 39A)
3.20.4.1 OMA 11--Trip breakers 52/5A and 52-SAC on bus 5A and
52/6A and 52/TAO at bus 6A and Remove Control Power Fuses
OMA 11 was evaluated in Section 3.17.4.1 above. As stated
in Section 3.17.4.1, OMA 11 has acceptable margin for all fire
zones in Fire Area J.
3.20.4.2 OMA 12--Transfer Instrument Buses 23 and 23A to
Emergency Power Source
The licensee stated that instrument buses 23 and 23A could
experience a loss of their normal power source (125 VDC power panel 23)
as a result of fire in Fire Zone 39A. If this were to occur, the
licensee stated that OMA 12 is available to swap Instrument
Buses 23 and 23A to their backup power source (MCC-29A). If OMA
12 becomes necessary, the licensee stated that they have
assumed a 5.5-minute diagnosis period and that the required time to
perform the action is 2 minutes while the time available is 30 minutes,
which provides 22.5 minutes of margin.
3.20.5 Conclusion for Fire Area J (Fire Zone 39A)
Since the licensee described postulated fire scenarios and Fire
Zone 39A lacks an automatic fire detection or automatic fire
suppression system, and any discernable separation between the credited
and redundant equipment in the area, it is possible that a fire would
not be detected and extinguished in a reasonable amount of time to
ensure that at least one train of equipment remains free of fire damage
following a fire event. Although there is 50 minutes of margin
available for OMA 11 and 22.5 minutes of margin available for
OMA 12, Fire Zone 39A still lacks adequate defense-in-depth.
Therefore, the NRC staff finds that the defense-in-depth is
insufficient to demonstrate reasonable assurance that safe shutdown can
be achieved for a fire in Fire Zone 39A and that OMAs 11 and
12 are unacceptable for the purpose of providing the level of
protection intended by the regulation. Therefore, the NRC staff finds
that an exemption from III.G.2 based on these OMAs cannot be granted
for Fire Zone 39A.
3.21 Fire Area J--Unit 1 Control Room, Turbine Building, Superheater
Building, Nuclear Service Building, Chemical Systems Building,
Administration Building, Screenwell House, and Unit 2 Turbine Building
(Fire Zone 43A--Ground Floor, Elevation 15-0'' Unit 2 Turbine Building)
3.21.1 Fire Prevention
The licensee stated that the fire loading in this zone is low and
that the fixed combustibles in this zone consist of cable insulation,
lube oil, plastic, wood, electrical panels, and cabinets and that the
transient combustibles in this zone consist of trash, cardboard drums,
cleaning rags, lube oil, plastic, fiberglass ladders, and paint. The
licensee also stated that the ignition sources in this zone consist of
cables, junction boxes, MCC, motors, pumps, electrical cabinets, high
voltage arcing faults, and an air dryer. The licensee further stated
that since Fire Area J does not contain safety-related structures,
systems or components, it is not subject to the explicit transient
combustible controls of procedure EN-DC-161. However, operator rounds
performed each shift provide for the monitoring of combustibles that
could present an unacceptable fire safety challenge. In addition, the
licensee stated that procedures OAP-017 (Plant Surveillance and
Operator Rounds) and EN-MA-132 (Housekeeping) include guidance for
monitoring general area cleanliness as well as monitoring for
accumulations of combustibles.
3.21.2 Detection, Control, and Extinguishment
The licensee stated that Fire Zone 43A does not have a fire
detection or automatic fire suppression system installed.
3.21.3 Preservation of Safe Shutdown Capability
The licensee stated that Fire Zone 43A has an approximate floor
area of
[[Page 7201]]
6,600 square feet and an approximate ceiling height of 21'-0''. The
licensee stated that cable JC2-YA9, which is associated with Buses 5A
and 6A, is routed through Fire Zone 43A in a tray located approximately
15 feet above the floor and that ignition sources in the zone located
less than 20 feet horizontally from the cable consist of two MCCs, an
air dryer skid, 6.9 kV switchgear, and an electrical cabinet. According
to the licensee, the MCCs are located under the cable routing separated
from the cable by approximately 7.7 feet vertically, the air dryer skid
is separated from the cable by approximately 6.1 feet horizontally, the
electrical cabinet is separated from the cable by approximately 2 feet
horizontally and 9.2 feet vertically, and the 6.9 kV switchgear is
separated from the cable by approximately 0.7 feet horizontally and 7.7
feet vertically.
The licensee also stated that cable AC4-BA6 is routed through Fire
Zone 43A in a tray located approximately 12 feet above the floor and
that ignition sources in the zone located less than 20 feet
horizontally from the cable consist of 6.9 kV switchgear and an
electrical cabinet. According to the licensee, the 6.9 kV switchgear is
separated from the cable by zero feet horizontally and approximately
3.7 feet vertically and the electrical cabinet is separated from the
cable by approximately 6 feet horizontally.
The licensee also stated that cable AA3-BA5 is associated with
instrument buses 23 and 23A and is routed through Fire Zone 43A in tray
located approximately 14 feet above the floor and that ignition sources
in the zone located less than 20 feet horizontally from the cable
consist of 6.9 kV switchgear and an electrical cabinet. According to
the licensee, the 6.9 kV switchgear is separated from the cable by
approximately 0 feet horizontally and 5 feet vertically and the
electrical cabinet is separated from the cable by approximately 3 feet
horizontally and 7 feet vertically.
The licensee also stated that cable AD1-BA8 is associated with
instrument buses 23 and 23A and is routed through Fire Zone 43A in tray
located approximately 14 feet above the floor and that ignition sources
in the zone located less than 20 feet horizontally from the cable
consist of 6.9 kV switchgear and an electrical cabinet. According to
the licensee, the 6.9 kV switchgear is separated from the cable by
approximately 0 feet horizontally and 5.6 feet vertically and the
electrical cabinet is separated from the cable by approximately 6 feet
horizontally.
The licensee stated that cable ECE19-MN3/01, which is associated
with valve LCV-112B, is routed through Fire Zone 43A in a cable tray
located approximately 13 feet above the floor and that ignition sources
in the zone located less than 20 feet horizontally from the cable
consist of an MCC, an air dryer skid, 6.9 kV switchgear, a portable
Duraline power station, and an electrical cabinet. According to the
licensee, the MCC is separated from the cable by approximately 3.2 feet
horizontally and 0 feet vertically, the air dryer skid is separated
from the cable by approximately 7.7 feet horizontally and 2.6 feet
vertically, the electrical cabinet is separated from the cable by
approximately 2 feet horizontally and 7.3 feet vertically, the 6.9 kV
switchgear is separated from the cable by approximately 0.7 feet
horizontally and 5.8 feet vertically, and the Duraline power station is
separated from the cable by approximately 19.5 feet horizontally.
As discussed in Section 3.0 above, the licensee did not demonstrate
any separation between credited and redundant trains of equipment.
3.21.4 OMAs Credited for a Fire in Fire Area J (Fire Zone 43A)
3.21.4.1 OMA 11--Trip Breakers 52/5A and 52-SAC on Bus 5A and
52/6A and 52/TAO at Bus 6A and Remove Control Power Fuses
OMA 11 was evaluated in Section 3.17.4.1 above. As stated
in Section 3.17.4.1, OMA 11 has acceptable margin for all fire
zones in Fire Area J.
3.21.4.2 OMA 12--Transfer Instrument Buses 23 and 23A to
Emergency Power Source
The licensee stated that Instrument buses 23 and 23A could
experience a loss of their normal power source (125 VDC power panel 23)
as a result of fire in Fire Zone 43A. If a fire were to occur and
causes a loss of offsite power and damages the cables identified above,
the licensee stated that OMA 12 is available to swap
Instrument Buses 23 and 23A to their backup power source (MCC-29A). If
OMA 12 becomes necessary, the licensee stated that they have
assumed a 5.5-minute diagnosis period and that the required time to
perform the action is 2 minutes while the time available is 30 minutes,
which provides 22.5 minutes of margin.
3.21.4.3 OMA 13--Align Charging Pump Suction to RWST
The licensee stated that fire-induced cable damage may render
alternate charging pump suction supply valve LCV-112B (normally closed
RWST outlet valve) inoperable. In the event that cable failures have
rendered LCV-112B inoperable, local valve manipulations are required to
support alignment of the charging pump suction to the alternate source,
the RWST.
If a fire were to occur and renders the alternate charging pump
suction supply valve LCV-112B inoperable, the licensee stated that OMA
13 is available to locally close valve LCV-112C and open
manual valve 288 to provide a bypass around RWST outlet valve LCV-112B
and provide water to the charging pump suction. If OMA 13
becomes necessary, the licensee stated that they have assumed a 14-
minute diagnosis period and that the required time to perform the
action is 18 minutes while the time available is 75 minutes, which
provides 43 minutes of margin.
3.21.5 Conclusion for Fire Area J (Fire Zone 43A)
Since the licensee described postulated fire scenarios and Fire
Zone 43A lacks an automatic fire detection or automatic fire
suppression system, and any discernable separation between the credited
and redundant equipment in the area, it is possible that a fire would
not be detected and extinguished in a reasonable amount of time to
ensure that at least one train of equipment remains free of fire damage
following a fire event. Although there is 50 minutes of margin
available for OMA 11, 22.5 minutes of margin available for OMA
12, and 43 minutes of margin available for OMA 13,
Fire Zone 43A lacks adequate defense-in-depth. Therefore, the NRC staff
finds that the defense-in-depth is insufficient to demonstrate
reasonable assurance that safe shutdown can be achieved for a fire in
Fire Zone 43A and that OMAs 11, 12, and 13
are unacceptable for the purpose of providing the level of protection
intended by the regulation. Therefore, the NRC staff finds that an
exemption from III.G.2 based on these OMAs cannot be granted for Fire
Zone 43A.
3.22 Fire Area J--Unit 1 Control Room, Turbine Building, Superheater
Building, Nuclear Service Building, Chemical Systems Building,
Administration Building, Screenwell House, and Unit 2 Turbine Building
(Fire Zone 45A--Ground Floor, Elevation 15-0'' and 3'-3'' of the Unit 2
Turbine Building)
3.22.1 Fire Prevention
The licensee stated that the fire loading in this zone is low and
that the fixed combustibles in this zone consist of cable insulation,
lube oil, vinyl insulation, and hydrogen and that the transient
combustibles in this zone
[[Page 7202]]
consist of trash, cardboard drums, lube oil, fiberglass ladders, paint,
and radiation boundaries. The licensee also stated that the ignition
sources in this zone consist of cables, junction boxes, MCC, motors,
pumps, and electrical cabinets. The licensee further stated that since
Fire Area J does not contain safety-related structures, systems or
components, it is not subject to the explicit transient combustible
controls of procedure EN-DC-161. However, operator rounds performed
each shift provide for the monitoring of combustibles that could
present an unacceptable fire safety challenge. In addition, the
licensee stated that procedures OAP-017 (Plant Surveillance and
Operator Rounds) and EN-MA-132 (Housekeeping) include guidance for
monitoring general area cleanliness as well as monitoring for
accumulations of combustibles.
3.22.2 Detection, Control, and Extinguishment
The licensee stated that Fire Zone 45A does not have a fire
detection or automatic fire suppression system installed.
3.22.3 Preservation of Safe Shutdown Capability
The licensee stated that Fire Zone 45A has an approximate floor
area of 5,380 square feet and an approximate ceiling height of 12'-4''.
The licensee stated that cable AG5-XA5, which affects buses 5A and 6A,
is located in Fire Zone 45A and that ignition sources in the zone
located less than 20 feet horizontally from cable AG5-XA5 consist of
seven electrical cabinets, a 150KVA dry transformer, three motors, and
an MCC. According to the licensee, three electrical cabinets are
located under the cable separated by approximately 3 feet vertically or
greater, four electrical cabinets are separated from the cable by
approximately 2 feet horizontally or greater, the 150KVA dry
transformer is separated from the cable by approximately 1.6 feet
horizontally and 6.7 feet vertically. The motors are separated from the
cable by approximately 4.6 feet horizontally or greater, and the MCC is
separated from the cable by approximately 7.5 feet horizontally. As
discussed in Section 3.0 above, the licensee could not demonstrate any
separation between credited and redundant trains of equipment.
3.22.4 OMAs Credited for a Fire in Fire Area J (Fire Zone 45A)
3.22.4.1 OMA 11--Trip Breakers 52/5A and 52-SAC on Bus 5A and
52/6A and 52/TAO at Bus 6A and Remove Control Power Fuses
OMA 11 was evaluated in Section 3.17.4.1 above. As stated
in Section 3.17.4.1, OMA 11 has acceptable margin for all fire
zones in Fire Area J.
3.22.5 Conclusion for Fire Area J (Fire Zone 45A)
Since the licensee described postulated fire scenarios and Fire
Zone 45A lacks an automatic fire detection or automatic fire
suppression system, and any discernable separation between the credited
and redundant equipment in the area, it is possible that a fire would
not be detected and extinguished in a reasonable amount of time to
ensure that at least one train of equipment remains free of fire damage
following a fire event. Although there is 50 minutes of margin
available for OMA 11, Fire Zone 45A still lacks adequate
defense-in-depth. The NRC staff finds that the defense-in-depth is
insufficient to demonstrate reasonable assurance that safe shutdown can
be achieved for a fire in Fire Zone 45A and that OMA 11 is
unacceptable for the purpose of providing the level of protection
intended by the regulation. Therefore, the NRC staff finds that an
exemption from III.G.2 based on OMA 11 cannot be granted for
Fire Zone 45A.
3.23 Fire Area J--Unit 1 Control Room, Turbine Building, Superheater
Building, Nuclear Service Building, Chemical Systems Building,
Administration Building, Screenwell House, and Unit 2 Turbine Building
(Fire Zone 46A--Ground Floor, Elevation 12'-0'' and 3'-3'' Unit 2
Turbine Building)
3.23.1 Fire Prevention
The licensee stated that the fire loading in this zone is low and
that the fixed combustibles in this zone consist of cable insulation
and lube oil and that the transient combustibles in this zone consist
of trash, cleaning rags, lube oil, and paint. The licensee also stated
that the ignition sources in this zone consist of cables, junction
boxes, motors, pumps, and electrical cabinets. The licensee further
stated that since Fire Area J does not contain safety-related
structures, systems or components, it is not subject to the explicit
transient combustible controls of procedure EN-DC-161. However,
operator rounds performed each shift provide for the monitoring of
combustibles that could present an unacceptable fire safety challenge.
In addition, the licensee stated that procedures OAP-017, ``Plant
Surveillance and Operator Rounds,'' and EN-MA-132, ``Housekeeping,''
include guidance for monitoring general area cleanliness as well as
monitoring for accumulations of combustibles.
3.23.2 Detection, Control, and Extinguishment
The licensee stated that Fire Zone 46A does not have a fire
detection or automatic fire suppression system installed.
3.23.3 Preservation of Safe Shutdown Capability
The licensee stated that Fire Zone 46A has an approximate floor
area of 12,350 square feet and an approximate ceiling height of 12'-
4''. The licensee stated that cable JC2-YA9, which is associated with
Buses 5A and 6A, is routed through Fire Zone 46A in a tray located
approximately 15 feet above the floor and that ignition sources in the
zone located less than 20 feet horizontally from the cable consist of
two MCCs, an air dryer skid, 6.9kV switchgear, and an electrical
cabinet. According to the licensee, the MCCs are located under the
cable routing separated from the cable by approximately 7.7 feet
vertically, the air dryer skid is separated from the cable by
approximately 6.1 feet horizontally, the electrical cabinet is
separated from the cable by approximately 2 feet horizontally and 9.2
feet vertically, and the 6.9kV switchgear is separated from the cable
by approximately 0.7 feet horizontally and 7.7 feet vertically.
The licensee also stated that cable JB1-L91, which is associated
with instrument buses 23 and 23A, is routed through the Fire Zone 46A.
The licensee also stated that cable ECE19-MN3/01, which is
associated with valve LCV-112B, is routed through Fire Zone 46A in a
cable tray located approximately 13 feet above the floor and that
ignition sources in the zone located less than 20 feet horizontally
from the cable consist of an MCC, an air dryer skid, 6.9kV switchgear,
a portable Duraline power station, and an electrical cabinet. According
to the licensee, the MCC is separated from the cable by approximately
3.2 feet horizontally and 0 feet vertically, the air dryer skid is
separated from the cable by approximately 7.7 feet horizontally and 2.6
feet vertically, the electrical cabinet is separated from the cable by
approximately 2 feet horizontally and 7.3 feet vertically, the 6.9kV
switchgear is separated from the cable by approximately 0.7 feet
horizontally and 5.8 feet vertically, and the Duraline power station is
separated from the
[[Page 7203]]
cable by approximately 19.5 feet horizontally.
As discussed in Section 3.0 above, the licensee did not demonstrate
any separation between credited and redundant trains of equipment.
3.23.4 OMAs Credited for a Fire in Fire Area J (Fire Zone 46A)
3.23.4.1 OMA 11--Trip Breakers 52/5A and 52-SAC on Bus 5A and
52/6A and 52/TAO at Bus 6A and Remove Control Power Fuses
OMA 11 was evaluated in Section 3.17.4.1 above. As stated
in Section 3.17.4.1, OMA 11 has acceptable margin for all fire
zones in Fire Area J.
3.23.4.2 OMA 12--Transfer Instrument Buses 23 and 23A to
Emergency Power Source
The licensee stated that instrument buses 23 and 23A could
experience a loss of their normal power source (125 VDC power panel 23)
as a result of fire in Fire Zone 46A. If this were to occur, the
licensee stated that OMA 12 is available to swap instrument
buses 23 and 23A to their backup power source (MCC-29A). If OMA
12 becomes necessary, the licensee stated that they have
assumed a 5.5-minute diagnosis period and that the required time to
perform the action is 2 minutes while the time available is 30 minutes,
which provides 22.5 minutes of margin.
3.23.4.3 OMA 13--Align Charging Pump Suction to RWST
The licensee stated that fire-induced cable damage may render
alternate charging pump suction supply valve LCV-112B (normally closed
RWST outlet valve) inoperable. In the event that cable failures have
rendered LCV-112B inoperable, this valve is required to be opened to
support alignment of charging pump suction to the alternate source, the
RWST.
If a fire were to occur and it renders alternate charging pump
suction supply valve LCV-112B inoperable, the licensee stated that OMA
13 is available to locally close valve LCV-112C and open
manual valve 288 to provide a bypass around RWST outlet valve LCV-112B
and provide water to the charging pump suction. If OMA 13
becomes necessary, the licensee stated that they have assumed a 14-
minute diagnosis period and that the required time to perform the
action is 18 minutes while the time available is 75 minutes, which
provides 43 minutes of margin.
3.23.5 Conclusion for Fire Area J (Fire Zone 46A)
Since the licensee described postulated fire scenarios and Fire
Zone 46A lacks an automatic fire detection or automatic fire
suppression system, and any discernable separation between the credited
and redundant equipment in the area, it is possible that a fire would
not be detected and extinguished in a reasonable amount of time to
ensure that at least one train of equipment remains free of fire damage
following a fire event. Although there is 50 minutes of margin
available for OMA 11, 22.5 minutes of margin available for OMA
12, and 43 minutes of margin available for OMA 13,
Fire Zone 46A still lacks adequate defense-in-depth. The NRC staff
finds that the defense-in-depth is insufficient to demonstrate
reasonable assurance that safe shutdown can be achieved for a fire in
Fire Zone 46A and that OMAs