[Federal Register Volume 71, Number 85 (Wednesday, May 3, 2006)]
[Notices]
[Pages 26118-26122]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-6678]
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NUCLEAR REGULATORY COMMISSION
Notice of Opportunity To Comment on Model Safety Evaluation and
Model License Amendment Request on Technical Specification Improvement
Regarding Use of the Improved Bank Position Withdrawal Sequence for
General Electric 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 U.S. Nuclear
Regulatory Commission (NRC) has prepared a model license amendment
request (LAR), model safety evaluation (SE), and model proposed no
significant hazards consideration (NSHC) determination related to
changes to Standard Technical Specification (STS) 3.1.6, ``Rod Pattern
Control,'' and STS 3.3.2.1, ``Control Rod Block Instrumentation'' for
NUREG-1433 and NUREG-1434. The proposed changes would revise the Bases
for STS 3.1.6, ``Rod Pattern Control,'' and STS 3.3.2.1, ``Control Rod
Block Instrumentation'' to allow licensees to use an improved control
rod bank position withdrawal sequence (BPWS) when performing a reactor
shutdown. In addition, for NUREG-1434 licensees, the proposed changes
would add a footnote to Table 3.3.2.1-1, ``Control Rod Block
Instrumentation.'' The requirements for implementing the improved BPWS
are described in General Electric Licensing Topical Report (LTR) NEDO-
33091-A, Revision 2, ``Improved BPWS Control Rod Insertion Process,''
dated July 2004. The General Electric Boiling Water Reactor Owners
Group (BWROG) participants in the Technical Specifications Task Force
(TSTF) proposed these changes to the STS in TSTF-476, Revision 0,
``Improved BPWS Control Rod Insertion Process (NEDO-33091).''
The purpose of these models is to permit the NRC to efficiently
process amendments to incorporate these changes into plant-specific
Technical Specifications (TS) for General Electric Boiling Water
Reactors (BWRs). Licensees of nuclear power reactors to which the
models apply can request amendments conforming to the models. In such a
request, a licensee should confirm the applicability of the model LAR,
model SE and NSHC determination to its plant. The NRC staff is
requesting comments on the model LAR, model SE and NSHC determination
before announcing their availability for referencing in license
amendment applications.
DATES: The comment period expires 30 days from the date of this
publication. 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.
Submit comments by electronic mail to: [email protected].
[[Page 26119]]
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.
FOR FURTHER INFORMATION CONTACT: Eric Thomas, Mail Stop: O-12H2,
Division of Inspection and Regional Support, Office of Nuclear Reactor
Regulation, U.S. Nuclear Regulatory Commission, Washington, DC 20555-
0001, telephone (301) 415-6772.
SUPPLEMENTARY INFORMATION:
Background
Regulatory Issue Summary 2000-06, ``Consolidated Line Item
Improvement Process [CLIIP] for Adopting Standard Technical
Specifications Changes for Power Reactors,'' was issued on March 20,
2000. The 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 changes the
Bases for sections 3.1.6 and 3.3.2.1 of the General Electric BWR STS,
Revision 3 of NUREG-1433 and NUREG-1434, and Table 3.3.2.1-1 in the
NUREG-1434 STS. 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.
Following the public comment period, the model LAR and model SE will be
finalized, and posted on the NRC Web page. Each amendment application
made in response to the notice of availability will be processed and
noticed in accordance with applicable NRC rules and procedures.
This notice involves implementation of an improved BPWS, which
would allow licensees of General Electric BWRs to follow the improved
BPWS when inserting control rods into the core during a reactor
shutdown. By letter dated August 30, 2004, the BWROG proposed these
changes for incorporation into the STS as TSTF-476, Revision 0. These
changes are based on the NRC staff-approved LTR NEDO-33091-A,
``Improved BPWS Control Rod Insertion Process,'' dated July 2004, as
approved by NRC in an SE dated June 16, 2004, accessible electronically
from the Agency-wide Documents Access and Management System's (ADAMS)
Public Electronic Reading Room on the Internet (ADAMS Accession No.
ML041700479) 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 Public Document Room Reference staff by telephone at 1-800-397-
4209, 301-415-4737, or by e-mail to [email protected].
Applicability
These proposed changes will revise the Section 3.6.1 and Section
3.3.2.1 TS Bases for General Electric BWR/4 and BWR/6 plants, and TS
Table 3.3.2.1-1 for BWR/6 plants.
To efficiently process the incoming license amendment applications,
the NRC staff requests that each licensee applying for the changes
addressed by TSTF-476, Revision 0, using the CLIIP submit an LAR that
adheres to the following model. Any variations from the model LAR
should be explained in the licensee's submittal. Variations from the
approach recommended in this notice may require additional review by
the NRC staff, and may increase the time and resources needed for the
review. Significant variations from the approach, or inclusion of
additional changes to the license, will result in staff rejection of
the submittal. Instead, licensees desiring significant variations and/
or additional changes should submit a LAR that does not claim to adopt
TSTF-476.
Public Notices
This notice requests comments from interested members of the public
within 30 days of the date of this publication. Following the NRC
staff's evaluation of comments received as a result of this notice, the
NRC 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 model LAR, model SE or model NSHC
determination as a result of public comments). If the NRC 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 NRC 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.
Dated at Rockville, Maryland this 7th day of April 2006.
For the Nuclear Regulatory Commission.
Thomas H. Boyce,
Chief, Technical Specifications Branch, Division of Inspection and
Regional Support, Office of Nuclear Reactor Regulation.
Attachments--For Inclusion on the Technical Specification Web Page the
Following Example of an Application Was Prepared by the NRC Staff to
Facilitate the Adoption of Technical Specifications Task Force (TSTF)
Traveler TSTF-476, Revision 0 ``Improved BPWS Control Rod Insertion
Process (Nedo-33091).'' The Model Provides the Expected Level Of Detail
and Content for an Application to Adopt TSTF-476, Revision 0. Licensees
Remain Responsible for Ensuring That Their Actual Application Fulfills
Their Administrative Requirements as Well as NRC Regulations.
U.S. Nuclear Regulatory Commission, Document Control Desk,
Washington, DC 20555.
Subject: Plant Name, Docket No. 50-[XXX,] Re: Application For
Technical Specification Improvement To Adopt TSTF-476, Revision 0,
``Improved BPWS Control ROD Insertion Process (NEDO-33091)''.
Dear Sir or Madam: In accordance with the provisions of Section
50.90 of Title 10 of the Code of Federal Regulations (10 CFR),
[LICENSEE] is submitting a request for an amendment to the technical
specifications (TS) for [PLANT NAME, UNIT NOS.]. The proposed
changes would revise Sections 3.1.6, ``Rod Pattern Control,'' and
3.3.2.1, ``Control Rod Block Instrumentation,'' to allow [PLANT
NAME] to reference a new Banked Position Withdrawal Sequence (BPWS)
shutdown sequence in the TS Bases. [(BWR/6 only), In addition, a
footnote is added to Table 3.3.2.1-1, ``Control Rod Block
Instrumentation.'']
The changes are consistent with NRC-approved Industry Technical
Specification Task Force (TSTF) Standard Technical Specification
Change Traveler, TSTF-476, Revision 0, ``Improved BPWS Control Rod
Insertion Process (NEDO-33091).'' The availability of this TS
improvement was announced in the Federal Register on [DATE] ([ ]FR[
]) as part of the consolidated line item improvement process
(CLIIP).
Enclosure 1 provides a description and assessment of the
proposed changes, as well as confirmation of applicability.
Enclosure 2 provides the existing TS pages and TS Bases marked-up to
show the proposed changes. Enclosure 3 provides final TS pages and
TS Bases pages.
[LICENSEE] requests approval of the proposed license amendment
by [DATE], with the amendment being implemented [BY
[[Page 26120]]
DATE OR WITHIN X DAYS]. In accordance with 10 CFR 50.91, a copy of
this application, with enclosures, is being provided to the
designated [STATE] Official.
I declare under penalty of perjury under the laws of the United
States of America that I am authorized by [LICENSEE] to make this
request and that the foregoing is true and correct. [Note that
request may be notarized in lieu of using this oath or affirmation
statement]. If you should have any questions regarding this
submittal, please contact [ ].
Sincerely,
Name, Title
Enclosures:
1. Description and Assessment of Proposed Changes
2. Proposed Technical Specification Changes and Technical
Specification Bases Changes
3. Final Technical Specification and Bases pages
cc: NRR Project Manager, Regional Office, Resident Inspector, State
Contact, ITSB Branch Chief.
1.0 Description
This letter is a request to amend Operating License(s) [LICENSE
NUMBER(S)] for [PLANT/UNIT NAME(S)].
The proposed changes would revise Technical Specification (TS)
3.1.6, ``Rod Pattern Control'', and 3.3.2.1, ``Control Rod Block
Instrumentation,'' [(BWR/6 only) along with TS Table 3.3.2.1-1,
``Control Rod Block Instrumentation,''] to allow reference to an
improved, optional Bank Position Withdrawal Sequence (BPWS) in the
TS Bases for use during reactor shutdown.
The new BPWS is described in Topical Report NEDO-33091-A,
Revision 2, ``Improved BPWS Control Rod Insertion Process,'' dated
July 2004 (Reference 1), and approved by the NRC by Safety
Evaluation (SE) dated June 16, 2004 (ADAMS ML041700479) (Reference
2). Technical Specification Task Force (TSTF) change traveler TSTF-
476, Revision 0, ``Improved BPWS Control Rod Insertion Process
(NEDO-33091)'' was announced for availability in the Federal
Register on [DATE] as part of the consolidated line item improvement
process (CLIIP).
2.0 Proposed Changes
Consistent with NRC-approved TSTF-476, Revision 0, the proposed
TS changes include:
Revised TS Section 3.6.1 Bases to allow use of an
optional BPWS during plant shutdown.
Revised TS Section 3.3.2.1 Bases to allow reprogramming
of the rod worth minimizer during the optional BPWS shutdown
sequence.
[(BWR/6 only): Revised Table 3.3.2.1-1, ``Control Rod
Block Instrumentation,'' which adds a footnote that allows operators
to bypass the rod pattern controller if conditions for the optional
BPWS shutdown process are satisfied.]
3.0 Background
The background for this application is as stated in the model SE
in NRC's Notice of Availability published on [DATE ]([ ] FR [ ]),
the NRC Notice for Comment published on [DATE] ([ ] FR [ ]), and
TSTF-476, Revision 0.
4.0 Technical Analysis
[LICENSEE] has reviewed References 1 and 2, and the model SE
published on [DATE] ([ ] FR [ ]) as part of the CLIIP Notice for
Comment. [LICENSEE] has applied the methodology in Reference 1 to
develop the proposed TS changes. [LICENSEE] has also concluded that
the justifications presented in TSTF-476, Revision 0 and the model
SE prepared by the NRC staff are applicable to [PLANT, UNIT NOS.],
and justify this amendment for the incorporation of the changes to
the [PLANT] TS.
5.0 Regulatory Analysis
A description of this proposed change and its relationship to
applicable regulatory requirements and guidance was provided in the
NRC Notice of Availability published on [DATE] ([ ] FR [ ]), the NRC
Notice for Comment published on [DATE] ([ ] FR [ ]), and TSTF-476,
Revision 0.
5.1 Regulatory Commitments
As discussed in the model SE published in the Federal Register
on [DATE] ([ ] FR [ ]) for this technical specification improvement,
the following plant-specific verifications/commitments were
performed. In Reference 2 the NRC staff explained that the potential
for the control rod drop accident (CRDA) will be eliminated by the
following changes to the operational procedures, which [PLANT NAME]
[has made/will commit to make prior to implementation]:
1. Before reducing power to the low power setpoint (LPSP),
operators shall confirm control rod coupling integrity for all rods
that are fully withdrawn. Control rods that have not been confirmed
coupled and are in intermediate positions must be fully inserted
prior to power reduction to the LPSP. No action is required for
fully-inserted control rods.
If a shutdown is required and all rods, which are not confirmed
coupled, cannot be fully inserted prior to the power dropping below
the LPSP, then the original/standard BPWS must be adhered to.
2. After reactor power drops below the LPSP, rods may be
inserted from notch position 48 to notch position 00 without
stopping at the intermediate positions. However, GE Nuclear Energy
recommends that, to the maximum extent possible, operators insert
rods in the same order as specified for the original/standard BPWS.
If a plant is in the process of shutting down following improved
BPWS with the power below the LPSP, no control rod shall be
withdrawn unless the control rod pattern is in compliance with
standard BPWS requirements.
In addition to the procedure changes specified above, the staff
previously concluded, based on its review of NEDO-33091-A, that no
single failure of the boiling water reactor CRD mechanical or
hydraulic system can cause a control rod to drop completely out of
the reactor core during the shutdown process. Therefore, the proper
use of the improved BPWS will prevent a CRDA from occurring while
power is below the LPSP. [LICENSEE] has verified, in accordance with
NEDO-33091-A, Revision 2, that no single failure of the boiling
water reactor CRD mechanical or hydraulic system can cause a control
rod to drop completely out of the reactor core during the shutdown
process.
6.0 No Significant Hazards Consideration
[LICENSEE] has reviewed the proposed no significant hazards
consideration determination published in the Federal Register on
[DATE] ([ ] FR [ ]) as part of the CLIIP. [LICENSEE] has concluded
that the proposed determination presented in the notice is
applicable to [PLANT] and the determination is hereby incorporated
by reference to satisfy the requirements of 10 CFR 50.91(a).
7.0 Environmental Evaluation
[LICENSEE] has reviewed the environmental consideration included
in the model SE published in the Federal Register on [DATE] ([ ] FR
[ ]) as part of the CLIIP. [LICENSEE] has concluded that the staff's
findings presented therein are applicable to [PLANT] and the
determination is hereby incorporated by reference for this
application.
8.0 References
1. Topical Report NEDO-33091-A, Revision 2, ``Improved BPWS
Control Rod Insertion Process,'' dated July 2004.
2. NRC Safety Evaluation (SE) approving Topical Report NEDO-
33091, Revision 2, ``Improved BPWS Control Rod Insertion Process,''
dated June 16, 2004.
3. Federal Register Notices:
Notice for Comment published on [DATE] ([ ] FR [ ])
Notice of Availability published on [DATE] ([ ] FR [ ])
Model Safety Evaluation--U.S. Nuclear Regulatory Commission
Office of Nuclear Reactor Regulation--``Technical Specification
Task Force TSTF-476, Revision 0--``Improved BPWS Control Rod
Insertion Process (NEDO-33091)
1.0 Introduction
By letter dated [------, 20--], [LICENSEE] (the licensee)
proposed changes to the technical specifications (TS) for [PLANT
NAME]. The requested changes are the adoption of TSTF-476, Revision
0, ``Improved BPWS Control Rod Insertion Process (NEDO-33091-A),''
to the Boiling Water Reactor (BWR) Standard Technical Specifications
(STS), which was proposed by the Technical Specifications Task Force
(TSTF) by letter on August 30, 2004. This TSTF involves changes to
NUREG-1433 and NUREG-1434 Section 3.1.6 ``Rod Pattern Control,''
Section 3.3.2.1 ``Control Rod Block Instrumentation,'' and Table
3.3.2.1-1 (NUREG-1434 only). The proposed TSTF would allow the use
of the improved bank position withdrawal sequence (BPWS) during
normal shutdowns if the conditions of NEDO-33091-A, Revision 2,
``Improved BPWS Control Rod Insertion Process,'' dated July 2004,
have been satisfied.
[[Page 26121]]
2.0 Regulatory Evaluation
The control rod drop accident (CRDA) is the design basis
accident for the subject TS changes. In order to minimize the impact
of a CRDA, the BPWS process was developed to minimize control rod
reactivity worth for BWR plants. The proposed improved BPWS further
simplifies the control rod insertion process, and in order to
evaluate it, the staff followed the guidelines of Standard Review
Plan Section 15.4.9, and referred to General Design Criterion (GDC)
28 of Appendix A to 10 CFR Part 50 as its regulatory requirement.
GDC 28 states that the reactivity control systems shall be designed
with appropriate limits on the potential amount and rate of
reactivity increase to assure that the effects of postulated
reactivity accidents can neither (1) result in damage to the reactor
coolant pressure boundary greater than limited local yielding nor
(2) sufficiently disturb the core, its support structures or other
reactor pressure vessel internals to impair significantly the
capability to cool the core.
3.0 Technical Evaluation
In its safety evaluation for Licensing Topical Report NEDO-
33091-A, ``Improved BPWS Control Rod Insertion Process,'' dated June
16, 2004, (ADAMS ML041700479) the staff determined that the
methodology described in TSTF-476, Revision 0, to incorporate the
improved BPWS into the STS, is acceptable.
TSTF-476, Revision 0, states that the improved BPWS provides the
following benefits: (1) Allows the plant to reach the all-rods-in
condition prior to significant reactor cool down, which reduces the
potential for re-criticality as the reactor cools down; (2) reduces
the potential for an operator reactivity control error by reducing
the total number of control rod manipulations; (3) minimizes the
need for manual scrams during plant shutdowns, resulting in less
wear on control rod drive (CRD) system components and CRD
mechanisms; and, (4) eliminates unnecessary control rod
manipulations at low power, resulting in less wear on reactor manual
control and CRD system components.
[PLANT NAME] has been approved to use the improved BPWS, and the
potential for a CRDA with power below the low power setpoint (LPSP)
has been eliminated. The safety evaluation for NEDO-33091-A
explained that the potential for the CRDA will be eliminated by the
following changes to operational procedures, which [PLANT NAME] [has
made/will commit to make prior to implementation]:
1. Before reducing power to the LPSP, operators shall confirm
control rod coupling integrity for all rods that are fully
withdrawn. Control rods that have not been confirmed coupled and are
in intermediate positions must be fully inserted prior to power
reduction to the LPSP. No action is required for fully-inserted
control rods.
If a shutdown is required and all rods that are not confirmed
coupled cannot be fully inserted prior to power dropping below the
LPSP, then the original/standard BPWS must be adhered to.
2. After reactor power drops below the LPSP, rods may be
inserted from notch position 48 to notch position 00 without
stopping at the intermediate positions. However, GE Nuclear Energy
recommends that, to the maximum extent possible, operators insert
rods in the same order as specified for the original/standard BPWS.
If a plant is in the process of shutting down following improved
BPWS with the power below the LPSP, no control rod shall be
withdrawn unless the control rod pattern is in compliance with
standard BPWS requirements.
In addition to the procedure changes specified above, the staff
previously verified during its review of NEDO-33091-A, Revision 2,
that no single failure of the boiling water reactor CRD mechanical
or hydraulic system can cause a control rod to drop completely out
of the reactor core during the shutdown process. Therefore, the
proper use of the improved BPWS will prevent a CRDA from occurring
while power is below the LPSP.
The staff finds the proposed Technical Specification changes in
[PLANT NAME's] amendment request properly incorporate the improved
BPWS procedure into the STS, and that [PLANT NAME] accurately
adopted TSTF-476 and the requisite procedural changes. Therefore,
the staff approves the [PLANT NAME] license amendment request to
adopt TSTF-476, Revision 0.
4.0 State Consultation
In accordance with the Commission's regulations, the [------]
State official was notified of the proposed issuance of the
amendment. The State official had [(1) no comments or (2) the
following comments--with subsequent disposition by the staff].
5.0 Environmental Consideration
The amendment[s] change[s] 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 or surveillance
requirements. The NRC staff has determined that the amendment
involves 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 amendment involves no
significant hazards consideration and there has been no public
comment on such finding published [DATE] ([ ] FR [ ]). Accordingly,
the amendment meets 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
amendment.
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 amendment 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: [Plant name] requests adoption
of an approved change to the standard technical specifications (STS)
for Boiling Water Reactor (BWR) Plants (NUREG-1433 & NUREG-1434) and
plant specific technical specifications (TS), to allow the use of
the improved bank position withdrawal sequence (BPWS) during normal
shutdowns in accordance with NEDO-33091-A, Revision 2, ``Improved
BPWS Control Rod Insertion Process,'' dated July 2004. The changes
are consistent with NRC approved Industry/Technical Specification
Task Force (TSTF) Standard Technical Specification Change Traveler,
TSTF-476.
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.
The proposed changes modify the TS to allow the use of the
improved bank position withdrawal sequence (BPWS) during normal
shutdowns if the conditions of NEDO-33091-A, Revision 2, ``Improved
BPWS Control Rod Insertion Process,'' July 2004, have been
satisfied. The staff finds that the licensee's justifications to
support the specific TS changes are consistent with the approved
topical report and TSTF-476. Since the change only involves changes
in control rod sequencing, the probability of an accident previously
evaluated is not significantly increased, if at all. The
consequences of an accident after adopting TSTF-476 are no different
than the consequences of an accident prior to adopting TSTF-476.
Therefore, the consequences of an accident previously evaluated are
not significantly affected by this change. Therefore, this change
does not involve a significant increase in the probability or
consequences of an accident previously evaluated.
Criterion 2--The Proposed Change Does Not Create the Possibility
of a New or Different Kind of Accident from any Previously
Evaluated.
The proposed change will not introduce new failure modes or
effects and will not, in the absence of other unrelated failures,
lead to an accident whose consequences exceed the consequences of
accidents previously evaluated. The control rod drop accident (CRDA)
is the design basis accident for the subject TS changes. This change
does not create the possibility of a new or different kind of
accident from an accident previously evaluated.
Criterion 3--The Proposed Change Does Not Involve a Significant
Reduction in the Margin of Safety.
The proposed change, TSTF-476, incorporates the improved BPWS,
previously approved in NEDO-33091-A, into the improved TS. Control
rod drop accident
[[Page 26122]]
(CRDA) is the design basis accident for the subject TS changes. In
order to minimize the impact of a CRDA, the BPWS process was
developed to minimize control rod reactivity worth for BWR plants.
The proposed improved BPWS further simplifies the control rod
insertion process and, in order to evaluate it, the staff followed
the guidelines of Standard Review Plan Section 15.4.9, and referred
to General Design Criterion 28 of Appendix A to 10 CFR part 50 as
its regulatory requirement. The TSTF stated the improved BPWS
provides the following benefits: (1) Allows the plant to reach the
all-rods-in condition prior to significant reactor cool down, which
reduces the potential for re-criticality as the reactor cools down;
(2) reduces the potential for an operator reactivity control error
by reducing the total number of control rod manipulations; (3)
minimizes the need for manual scrams during plant shutdowns,
resulting in less wear on control rod drive (CRD) system components
and CRD mechanisms; and, (4) eliminates unnecessary control rod
manipulations at low power, resulting in less wear on reactor manual
control and CRD system components. The addition of procedural
requirements and verifications specified in NEDO-33091-A, along with
the proper use of the BPWS will prevent a control rod drop accident
(CRDA) from occurring while power is below the low power setpoint
(LPSP). The net change to the margin of safety is insignificant.
Therefore, this change does not involve a significant reduction in a
margin of safety.
Based upon the reasoning presented above and the previous
discussion of the amendment request, the requested change does not
involve a significant hazards consideration.
Dated at Rockville, Maryland, this ---- day of ------------, 2006.
For the Nuclear Regulatory Commission.
Project Manager, Plant Licensing Branch [ ], Division of Operating
Reactor Licensing, Office of Nuclear Reactor Regulation.
[FR Doc. E6-6678 Filed 5-2-06; 8:45 am]
BILLING CODE 7590-01-P