[Federal Register Volume 68, Number 36 (Monday, February 24, 2003)]
[Notices]
[Pages 8637-8640]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-4263]
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NUCLEAR REGULATORY COMMISSION
Notice of Opportunity To Comment on Model Safety Evaluation on
Technical Specification 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: Request for comment.
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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)
relating to a change in the technical specification (TS) required
actions for inoperable vent and drain valves for the scram discharge
volume (S.V.) for boiling water reactors (BWRs). This proposed change
was proposed for incorporation into the standard technical
specifications (STS) by the BWR Owners Group (BWROG) participants in
the Technical Specification Task Force (TSTF) and is designated TSTF-
404, Revision 0. The proposed change to TS would allow isolation of one
or more S.V. vent or drain lines within 7 days if a single vent or
drain valve in the line is determined to be inoperable. The TS for most
BWRs do not currently include the option of isolating a vent or drain
line but instead require restoring a single inoperable S.V. vent or
drain valve to operable status within 7 days. Requirements are
maintained to isolate a line within 8 hours if both vent or drain
valves in a line are inoperable. This notice also includes a model no
significant hazards consideration (NSHC) determination relating to this
matter.
The purpose of these models is to permit the NRC to efficiently
process proposed amendments to incorporate this change into plant-
specific TS for BWRs. Licensees of nuclear power reactors to which the
models apply could request amendments conforming to the models. In such
a request, a licensee should confirm the applicability of the SE and
NSHC-determination to its reactor. The NRC staff is requesting comments
on the model SE and model NSHC determination before announcing their
availability for referencing in license amendment applications.
DATES: The comment period expires March 26, 2003. Comments received
after this date will be considered if it is practical to do so, but the
Commission is able to ensure consideration only for comments received
on or before this date.
ADDRESSES: Comments may be submitted either electronically or via U.S.
mail.
Submit written comments to: Chief, Rules and Directives Branch,
Division of Administrative Services, Office of Administration, Mail
Stop: T-6 D59, U.S. Nuclear Regulatory Commission, Washington, DC
20555-0001.
Hand deliver comments to: 11545 Rockville Pike, Rockville,
Maryland, between 7:45 a.m. and 4:15 p.m. on Federal workdays.
Copies of comments received may be examined at the NRC's Public
Document Room, One White Flint North, Public File Area O1 F21, 11555
Rockville Pike (first floor), Rockville, Maryland.
Comments may be submitted by electronic mail to [email protected].
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
Consolidated Line Item Improvement Process (CLIIP) is intended to
improve the efficiency and transparency of NRC licensing processes.
This is accomplished by processing proposed changes to the 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. This notice is soliciting comment on a proposed change to
the STS that revises requirements for the S.V. vent and drain valves
for BWRs. 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 proceed with announcing the availability of the change for
proposed adoption by licensees. Those licensees opting to apply for the
subject change to TSs 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 would be
processed and noticed in accordance with applicable rules and NRC
procedures.
This notice involves changes to required actions for inoperable
S.V. vent and drain valves for BWRs. This proposed change was proposed
for incorporation into the STS by the BWROG as TSTF-404, Revision 0.
The changes, provided in terms of Limiting Condition for Operation
(LCO) 3.1.8 in the STS for BWRs are provided below:
Current Requirements
LCO 3.1.8 Each S.V. Vent and Drain Valve Shall be Operable
Applicability: Modes 1 and 2.
Actions:
Note: Separate Condition Entry is allowed for each S.V. vent and
drain line.
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Condition Required action Completion time
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A. One or more S.V. vent or A.1 Restore Valve to 7 days.
drain lines with one valve Operable status.
inoperable.
B. One or more S.V. vent or B.1 Isolate the 8 hours.
drain lines with both valves associated line.
inoperable. Note: An isolated
line may be
unisolated under
administrative
control to allow
draining and venting
of the S.V.
C. Required Action and C.1 Be in Mode 3..... 12 hours.
associated Completion Time
not met.
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[[Page 8638]]
Revised Requirements
LCO 3.1.8 Each S.V. Vent and Drain Valve Shall be Operable
Applicability: Modes 1 and 2.
Actions:
Notes: 1. Separate Condition Entry is allowed for each S.V. vent
and drain line.
2. An isolated line may be unisolated under administrative
control to allow draining and venting of the S.V.
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Condition Required action Completion time
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A. One or more S.V. vent or A.1 Isolate the 7 days.
drain lines with one valve associated line.
inoperable.
B. One or more S.V. vent or B.1 Isolate the 8 hours.
drain lines with both valves associated line.
inoperable.
C. Required Action and C.1 Be in Mode 3..... 12 hours.
associated Completion Time
not met.
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Applicability
This proposed change to required actions for inoperable S.V. vent
and drain valves is applicable to BWRs.
The CLIIP does not prevent licensees from requesting an alternative
approach or proposing changes other than those proposed in TSTF-404.
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
This notice requests comments from interested members of the public
within 30 days of the date of publication in the Federal Register.
Following the staff's evaluation of comments received as a result of
this notice, the staff may reconsider the proposed change or may
proceed with announcing the availability of the change in a subsequent
notice (perhaps with some changes to the SE or proposed NSHC
determination as a result of public comments). If the staff announces
the availability of the change, licensees wishing to adopt the change
will submit an application in accordance with applicable rules and
other regulatory requirements. The staff will in turn issue for each
application a notice of consideration of issuance of amendment to
facility operating license(s), a proposed NSHC determination, and an
opportunity for a hearing. A notice of issuance of an amendment to
operating license(s) will also be issued to announce the revised
requirements for each plant that applies for and receives the requested
change.
Proposed Safety Evaluation
U.S. Nuclear Regulatory Commission, Office of Nuclear Reactor
Regulation, Consolidated Line Item Improvement, Technical Specification
Task Force (TSTF) Change TSTF-404, Scram Discharge Volume Vent and
Drain Valves
1.0 Introduction
By application dated [ ], [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 (S.V.) Vent and Drain Valves''] for the
condition of having one or more S.V. vent or drain lines with one valve
inoperable. These changes are based on Technical Specification 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 [ ] (xx 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 S.V. vent and drain valves are
defined in TS [3.1.8, ``Scram Discharge Volume (S.V.) Vent and Drain
Valves.''] The existing LCO [limiting condition for operation] [3.1.8],
requires that each S.V. vent and drain valve be operable. The
operability of all S.V. vent and drain valves ensures that the S.V.
vent and drain valves will close during a scram to contain reactor
water discharged to the S.V. 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 S.V.
If one or more S.V. 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 S.V. 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 S.V. The
S.V. vent and drain valve actions are inconsistent in
[[Page 8639]]
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 S.V.
The proposed change would revise the required actions to be more
consistent with the safety significance of one inoperable valve in a
S.V. line versus two inoperable valves in an S.V. 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 S.V. vent and drain valve in one or more S.V. 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 S.V. is moved to a note that applies to both Conditions
A (single inoperable valve) and B (both valves inoperable).
With one S.V. 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
S.V. 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 required action is not
required because the valve is repaired), 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 7days of the Completion Time
and a failure of the redundant valve(s). Alternately, if the inoperable
valve was initially closed, there would generally be ample time and
warning available to drain the S.V. before an automatic scram due to
S.V. high level would occur.
The allowance to administratively open a line that is isolated to
comply with the actions (to permit draining and venting the S.V.) 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 water in the line to be drained, to
preclude a reactor scram on S.V. high level. A reactor scram is
initiated if the S.V. water level in the instrument volume exceeds a
specified setpoint. The setpoint is chosen so that all control rods are
inserted before the S.V. has insufficient volume to accept a full
scram. Regarding the isolation of the S.V., the remaining operable S.V.
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 locally. Resetting the scram automatically closes
the scram outlet valves, isolating the control rod drive discharge path
to the S.V.
Based on the low probability of an event occurring during 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 S.V. 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.
Proposed No Significant Hazards Consideration Determination
Description of Amendment Request: The proposed amendment revises TS
[3.1.8, ``Scram Discharge Volume (S.V.) 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 S.V. vent and drain line
to be isolated when there are one or more S.V. vent or drain lines with
one valve inoperable instead or requiring the valve to be restored to
operable status within 7 days. With one S.V. 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 S.V. Following the completion of
the required action, the isolation function is fulfilled since the
associated line is
[[Page 8640]]
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 S.V.
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 S.V. to the point that it has
insufficient volume to accept a full scram. Maintaining the safety
functions related to isolation of the S.V. 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 14th day of February 2003.
For the Nuclear Regulatory Commission.
William H. Ruland,
Director, Project Directorate IV, Division of Licensing Project
Management, Office of Nuclear Reactor Regulation.
[FR Doc. 03-4263 Filed 2-21-03; 8:45 am]
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