[Federal Register Volume 68, Number 72 (Tuesday, April 15, 2003)]
[Notices]
[Pages 18294-18296]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-9196]
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NUCLEAR REGULATORY COMMISSION
Notice of Availability of Model Application Concerning Technical
Specifications Improvement Regarding Scram Discharge Volume Vent and
Drain Valves Actions for Boiling Water Reactors Using the Consolidated
Line Item Improvement Process
AGENCY: Nuclear Regulatory Commission.
ACTION: Notice of availability.
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SUMMARY: Notice is hereby given that the staff of the Nuclear
Regulatory Commission (NRC) has prepared a model safety evaluation
(SE), a model no significant hazards consideration (NSHC)
determination, and a model license amendment application relating to a
change in the technical specifications (TSs) required actions for
inoperable vent and drain valves for the scram discharge volume (SDV)
for boiling water reactors (BWRs). The purpose of these models is to
permit the NRC to efficiently process amendments that propose to
incorporate this change into plant-specific TS. Licensees of nuclear
power reactors to which the models apply may request amendments
utilizing the model application.
DATES: The NRC staff issued a Federal Register Notice (68 FR 8637,
February 24, 2003) which provided a model SE and a model NSHC
determination related to changing the completion times to address
inoperable valves in SDV vent or drain lines. The NRC staff hereby
announces that the model SE and NSHC determination may be referenced in
plant-specific applications. The staff has posted a model application
on the NRC web site to assist licensees in using the consolidated line
item improvement process (CLIIP) to incorporate this change. The NRC
staff can most efficiently consider applications based upon the model
application if the application is submitted within a year of this
Federal Register Notice.
FOR FURTHER INFORMATION CONTACT: William Reckley, Mail Stop: O-7D1,
Division of Licensing Project Management, Office of Nuclear Reactor
Regulation, U.S. Nuclear Regulatory Commission, Washington, DC 20555-
0001, telephone 301-415-1323.
SUPPLEMENTARY INFORMATION:
Background
Regulatory Issue Summary 2000-06, ``Consolidated Line Item
Improvement Process for Adopting Standard Technical Specifications
Changes for Power Reactors,'' was issued on March 20, 2000. The CLIIP
is intended to improve the efficiency of NRC licensing processes. This
is accomplished by processing proposed changes to the standard
technical specifications (STS) in a manner that supports subsequent
license amendment applications. The CLIIP includes an opportunity for
the public to comment on proposed changes to the STS following a
preliminary assessment by the NRC staff and finding that the change
will likely be offered for adoption by licensees. The CLIIP directs the
NRC staff to evaluate any comments received for a proposed change to
the STS and to either reconsider the change or to proceed with
announcing the availability of the change for proposed adoption by
licensees. Those licensees opting to apply for the subject change to TS
are responsible for reviewing the staff's evaluation, referencing the
applicable technical justifications, and providing any necessary plant-
specific information. Each amendment application made in response to
the notice of availability will be processed and noticed in accordance
with applicable rules and NRC procedures.
This notice involves changes to required actions for inoperable SDV
vent and drain valves for BWRs. This proposed change was proposed for
incorporation into the STS by the BWR Owners Group as Technical
Specification Task Force (TSTF)-404, Revision 0.
Applicability
This proposed change to required actions for inoperable SDV vent
and drain valves is applicable to BWRs.
The CLIIP does not prevent licensees from requesting an alternative
approach or proposing the changes without referencing the model SE and
the NSHC. Variations from the approach recommended in this notice may,
however, require additional review by the NRC staff and may increase
the time and resources needed for the review.
Public Notices
In a notice in the Federal Register dated February 24, 2003 (68 FR
8637), the staff requested comment on the use
[[Page 18295]]
of the CLIIP for proposed changes to the required actions and
completion times for inoperable SDV vent and drain valves at BWRs.
TSTF-404, as well as the NRC staff's SE and model application, may
be examined, and/or copied for a fee, at the NRC's Public Document
Room, located at One White Flint North, Public File Area 01 F21, 11555
Rockville Pike (first floor), Rockville, Maryland. Publicly available
records will be accessible electronically from the Agency wide
Documents Access and Management System's (ADAMS) Public Electronic
Reading Room on the Internet at the NRC Web site, http://www.nrc.gov/reading-rm/adams.html. Persons who do not have access to ADAMS or who
encounter problems in accessing the documents located in ADAMS, should
contact the NRC PDR Reference staff by telephone at 1-800-397-4209,
301-415-4737, or by e-mail to [email protected].
The staff received only informal comments regarding typographical
and editorial errors in the model SE and NSHC determination. A specific
change involves correcting the abbreviation for scram discharge volume
in the model SE and NSHC determination (from S.V. to SDV). Licensees
may reference in their plant-specific applications the corrected SE,
NSHC determination, and environmental assessment provided below.
U.S. Nuclear Regulatory Commission, Office of Nuclear Reactor
Regulation
Model Safety Evaluation--Consolidated Line Item Improvement Technical
Specifications Task Force (TSTF) Change TSTF-404, Scram Discharge
Volume Vent and Drain Valves
1.0 Introduction
By application dated [[squ]], [Licensee] (the licensee) requested
changes to the Technical Specifications (TSs) for [facility]. The
proposed changes would revise the required action within TS [3.1.8,
``Scram Discharge Volume (SDV) Vent and Drain Valves''] for the
condition of having one or more SDV vent or drain lines with one valve
inoperable. These changes are based on Technical Specifications Task
Force (TSTF) change traveler TSTF-404 (Revision 0) that has been
approved generically for the BWR [boiling water reactor]/4[6] Standard
Technical Specifications (STS), NUREG-1433 [1434], Revision 2. A notice
announcing the availability of this proposed TS change using the
consolidated line item improvement process (CLIIP) was published in the
Federal Register on [[squ]] (68 FR yyyyy).
2.0 Regulatory Evaluation
NRC regulations and review standards such as Appendix A, ``General
Design Criteria for Nuclear Power Plants,'' to 10 CFR Part 50 of Title
10 of the Code of Federal Regulations
(10 CFR), include specific requirements for reactor protection and
reactivity control systems. The reactor protection systems for BWRs use
a hydraulic system to insert control rods into the reactor core. During
an actuation of the reactor protection system (a scram), water is
exhausted from the control rod drive mechanisms to the SDVs. Proper
maintenance and operation of the SDVs in terms of instrumentation and
limiting water volumes are essential for assuring the reliability of
the reactor protection system (see NRC Bulletin 80-17, ``Failure of
Control Rods to Insert During A Scram at a BWR,'' related Orders to
specific facilities, and information provided in plant final safety
analysis reports and TS Bases). Maintaining the SDVs to ensure that
accumulated water does not hamper or slow the insertion of control rods
requires vent and drain valves. The vent and drain valves isolate
during a scram to limit the amount of coolant discharged so that
adequate core cooling is maintained and offsite doses remain within
regulatory limits.
Specific regulatory requirements for SDV vent and drain valves are
defined in TS [3.1.8, ``Scram Discharge Volume (SDV) Vent and Drain
Valves.''] The existing limiting condition for operation [3.1.8],
requires that each SDV vent and drain valve be operable. The
operability of all SDV vent and drain valves ensures that the SDV vent
and drain valves will close during a scram to contain reactor water
discharged to the SDV piping. Since the vent and drain lines are
provided with two valves in series, the single failure of one valve in
the open position will not impair the isolation function of the system.
Additionally, the valves are required to open on scram reset and during
plant operation to control the amount of water accumulating in the SDV
If one or more SDV vent and drain lines have a single valve that is
inoperable, the existing required action is to restore the valve(s) to
operable status within 7 days. If an inoperable valve is not restored
to operable status, a plant shutdown to MODE 3 is required within 12
hours. If one or more SDV vent or drain lines have both valves
inoperable, the associated line must be isolated within 8 hours. In
this condition, the plant is allowed to operate indefinitely. A note
associated with the required action clarifies that the valves may be
opened under administrative controls to allow draining of the SDV. The
existing SDV vent and drain valve required actions are inconsistent in
that, although the operational and safety concerns are similar for
having one or both valves in a line being inoperable, the actions for a
single inoperable valve do not allow for the isolation of the line and
administrative controls to support the draining of the SDV.
The proposed change would revise the required actions to be more
consistent with the safety significance of one inoperable valve in a
SDV line versus two inoperable valves in an SDV line.
3.0 Technical Evaluation
The proposed changes to TS 3.1.8 are:
1. Required Action A.1 is revised from restoring the single
inoperable SDV vent and drain valve in one or more SDV vent and drain
lines to operable status to isolating the associated line.
2. The Note to Required Action B.1 which allows an isolated line to
be unisolated under administrative controls for the purpose of draining
and venting the SDV is moved to a note that applies to both Conditions
A (single inoperable valve) and B (both valves inoperable).
With one SDV vent or drain valve inoperable in one or more lines,
the isolation function would be maintained since the redundant valve in
the affected line would perform its safety function of isolating the
SDV. The current ACTION statement allows 7 days to repair the
inoperable valve; the proposed change is to allow for the isolation of
the affected line and continue operation. If the affected line is not
isolated within the 7-day time period (or the inoperable valve is not
restored), the licensee would then be required to proceed to MODE 3 in
the next 12 hours. Maintaining the 7-day Completion Time is acceptable
because of the low probability of the concurrent events of a scram
within the 7 days of the Completion Time and a failure of the redundant
valve(s). Alternately, if the inoperable valve was initially closed,
there would be ample time and warning available to drain the SDV before
an automatic scram would occur due to SDV high level.
The allowance to administratively open a line that is isolated to
comply with the actions (to permit draining and venting the SDV) is
allowed by existing Required Action B.1. This allowance is being moved
to apply to all ACTIONS based on the change proposed to Action A. This
would allow any accumulated
[[Page 18296]]
water in the line to be drained, to preclude a reactor scram on SDV
high level. A reactor scram is initiated if the SDV water level in the
instrument volume exceeds a specified setpoint. The setpoint is chosen
so that all control rods are inserted before the SDV has insufficient
volume to accept a full scram. Regarding the isolation of the SDV, the
remaining operable SDV vent and drain valve(s) would close
automatically on a scram signal to isolate the lines. Or, if both
valves in a line were inoperable (and opened under this provision), the
reactor coolant release could be terminated by resetting the scram from
the control room, or by manually closing the valves. Resetting the
scram automatically closes the scram outlet valves, isolating the
control rod drive discharge path to the SDV.
Based on the low probability of an event occurring during the
defined Completion Time associated with this condition, the subsequent
isolation of the affected lines, and the ability to open and drain the
lines before an automatic scram due to SDV high water level, the
proposed change maintains the necessary safety features and is
therefore acceptable. [Note-optional section if licensee provides
markup of affected Bases pages: The change to TS [3.1.8] requires that
the licensee revise the discussion in the associated Bases section.
Although the licensee's application included possible wording for the
revised Bases discussion for TS [3.1.8], the licensee will formally
address the change to the Bases in accordance with [the Bases Control
Program or its administrative procedure for revising Bases]. The staff
does not believe that the Bases change will require prior NRC approval
when evaluated against the criteria in 10 CFR 50.59, ``Changes, tests,
and experiments,'' and, therefore, agrees that the revision of the
Bases to TS [3.1.8] should be addressed separately from this amendment
and should be included in a future update of the TS Bases in accordance
with [the Bases Control Program or the licensee's administrative
controls].
4.0 State Consultation
In accordance with the Commission's regulations, the [ ] State
official was notified of the proposed issuance of the amendments. The
State official had [(1) no comments or (2) the following comments--with
subsequent disposition by the staff].
5.0 Environmental Consideration
The amendments change a requirement with respect to the
installation or use of a facility component located within the
restricted area as defined in 10 CFR Part 20. The NRC staff has
determined that the amendments involve no significant increase in the
amounts and no significant change in the types of any effluents that
may be released offsite, and that there is no significant increase in
individual or cumulative occupational radiation exposure. The
Commission has previously issued a proposed finding that the amendments
involve no significant hazards consideration, and there has been no
public comment on such finding ( FR ). Accordingly, the amendments meet
the eligibility criteria for categorical exclusion set forth in 10 CFR
51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact
statement or environmental assessment need be prepared in connection
with the issuance of the amendments.
6.0 Conclusion
The Commission has concluded, based on the considerations discussed
above, that (1) there is reasonable assurance that the health and
safety of the public will not be endangered by operation in the
proposed manner, (2) such activities will be conducted in compliance
with the Commission's regulations, and (3) the issuance of the
amendments will not be inimical to the common defense and security or
to the health and safety of the public.
Model No Significant Hazards Consideration Determination
Description of Amendment Request: The proposed amendment revises TS
[3.1.8, ``Scram Discharge Volume (SDV) Vent and Drain Valves,''] to
allow a vent or drain line with one inoperable valve to be isolated
instead of requiring the valve to be restored to Operable status within
7 days.
Basis for proposed no significant hazards consideration
determination: As required by 10 CFR 50.91(a), an analysis of the issue
of no significant hazards consideration is presented below:
Criterion 1--The proposed change does not involve a significant
increase in the probability or consequences of an accident previously
evaluated.
A change is proposed to allow the affected SDV vent and drain line
to be isolated when there are one or more SDV vent or drain lines with
one valve inoperable instead or requiring the valve to be restored to
operable status within 7 days. With one SDV vent or drain valve
inoperable in one or more lines, the isolation function would be
maintained since the redundant valve in the affected line would perform
its safety function of isolating the SDV. Following the completion of
the required action, the isolation function is fulfilled since the
associated line is isolated. The ability to vent and drain the SDVs is
maintained and controlled through administrative controls. This
requirement assures the reactor protection system is not adversely
affected by the inoperable valves. With the safety functions of the
valves being maintained, the probability or consequences of an accident
previously evaluated are not significantly increased.
Criterion 2--The proposed change does not create the possibility of a
new or different kind of accident from any accident previously
evaluated.
The proposed change does not involve a physical alteration of the
plant (no new or different type of equipment will be installed) or a
change in the methods governing normal plant operation. Thus, this
change does not create the possibility of a new or different kind of
accident from any previously evaluated.
Criterion 3--The proposed change does not involve a significant
reduction in the margin of safety.
The proposed change ensures that the safety functions of the SDV
vent and drain valves are fulfilled. The isolation function is
maintained by redundant valves and by the required action to isolate
the affected line. The ability to vent and drain the SDVs is maintained
through administrative controls. In addition, the reactor protection
system will prevent filling of an SDV to the point that it has
insufficient volume to accept a full scram. Maintaining the safety
functions related to isolation of the SDV and insertion of control rods
ensures that the proposed change does not involve a significant
reduction in the margin of safety.
Therefore, the NRC staff proposes to determine that the amendment
request involves no significant hazards consideration.
Dated at Rockville, Maryland, this 8th day of April 2003.
For the Nuclear Regulatory Commission.
Herbert N. Berkow,
Director, Project Directorate IV, Division of Licensing Project
Management, Office of Nuclear Reactor Regulation.
[FR Doc. 03-9196 Filed 4-14-03; 8:45 am]
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