[Federal Register Volume 70, Number 100 (Wednesday, May 25, 2005)]
[Notices]
[Pages 30151-30156]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E5-2631]
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NUCLEAR REGULATORY COMMISSION
Notice of Opportunity To Comment on Model Safety Evaluation on
Technical Specification Improvement Regarding Revision to the
Completion Time in STS 3.6.1.3, ``Primary Containment Isolation
Valves'' 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 safety evaluation (SE)
relating to changes to the completion time (CT) in Standard Technical
Specification (STS) 3.6.1.3 ``Primary Containment Isolation Valves
(PCIVs).'' The proposed change to the Technical Specifications (TS)
would extend to 7 days the CT (or allowed outage time (AOT)) to restore
an inoperable PCIV or isolate the affected penetration flow path for
selected primary containment penetrations with two (or more) PCIVs and
for selected primary containment penetrations with only one PCIV. This
change is based on analyses provided in a generic topical report (TR)
submitted by the Boiling Water Reactors Owner's Group (BWROG). The
BWROG participants in the TS Task Force (TSTF) proposed this change to
the STS in Change Traveler No. TSTF-454, Revision 0. 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 amendments to incorporate this change into plant-specific 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 SE and NSHC determination to its plant. 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 60 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].
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: Bhalchandra Vaidya, 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) 415-3308.
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
PCIV CTs for the BWR/4 and BWR/6 STS, NUREG-1433, Revision 3 and NUREG-
1434, Revision 3, respectively. 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 NRC rules and procedures.
This notice involves an increase in the allowed CTs to restore an
inoperable PCIV or isolate the affected penetration flow path when
selected PCIVs are inoperable at BWRs. By letter dated September 5,
2003, the BWROG proposed this change for incorporation into the STS as
TSTF-454, Revision 0. This change is based on the NRC staff-approved
generic analyses contained in the BWROG TR NEDC-33046, ``Technical
Justification to Support Risk-Informed Primary Containment Isolation
Valve AOT Extensions for BWR Plants,'' submitted on May 3, 2002, as
supplemented by letter dated July 30, 2003, and as approved by the NRC
by letter and Safety Evaluation dated October 8, 2004, accessible
electronically from the Agencywide Documents Access and Management
System's (ADAMS) Public Electronic
[[Page 30152]]
Reading Room on the Internet (ADAMS Accession No. ML042660055) 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
This proposed change to revise the TS CTs for selected PCIVs is
applicable to General Electric BWRs.
To efficiently process the incoming license amendment applications,
the NRC staff requests each licensee applying for the changes addressed
by TSTF-454, Revision 0, using the CLIIP to address the seven plant-
specific conditions and the one commitment identified in the model SE,
as follows:
Conditions
1. Because not all penetrations have the same impact on core damage
frequency (CDF), large early release frequency (LERF), incremental
conditional core damage frequency (ICCDP), or incremental conditional
large early release frequency (ICLERP), a licensee's application must
provide supporting information that verifies the applicability of TR
NEDC-33046, including verification that the PCIV configurations for the
specific plant match the licensing topical report (LTR) and the risk
parameter values used in the LTR are bounding for the specific plant.
Any additional PCIV configurations or non-bounding risk parameter
values not evaluated by the LTR should be included in the licensee's
plant-specific analysis. [Note that PCIV configurations or non-bounding
risk parameter values outside the scope of the LTR will require NRC
staff review of the specific penetrations and related justifications
for the proposed CTs.]
2. The licensee's application must provide supporting information
that verifies that external event risk, either through quantitative or
qualitative evaluation, will not have an adverse impact on the
conclusions of the plant-specific analysis for extending the PCIV AOTs.
3. Because TR NEDC-33046 was based on generic plant
characteristics, each licensee adopting the TR must provide supporting
information that confirms plant-specific Tier 3 information in their
individual submittals. The licensee's application must provide
supporting information that discusses conformance to the requirements
of the maintenance rule (10 CFR 50.65(a)(4)), as they relate to the
proposed PCIV AOTs and the guidance contained in NUMARC 93.01, Section
11, as endorsed by Regulatory Guide (RG) 1.182, including verification
that the licensee's maintenance rule program, with respect to PCIVs,
includes a LERF/ICLERP assessment as part of the maintenance rule
process.
4. The licensee's application must provide supporting information
that verifies that a penetration remains intact during maintenance
activities, including corrective maintenance activities. Regarding
maintenance activities where the pressure boundary would be broken, the
licensee must provide supporting information that confirms that the
assumptions and results of the LTR remain valid. This includes the
assumption that maintenance on a PCIV will not break the pressure
boundary for more than the currently allowed AOT.
5. The licensee's application must provide supporting information
that verifies the operability of the remaining PCIVs in the associated
penetration flow path before entering the AOT for the inoperable PCIV.
6. Simultaneously entering the extended AOT for multiple PCIVs and
the resulting impact on risk were not specifically evaluated by the
BWROG. However, TR NEDC-33046 does state that multiple PCIVs can be out
of service simultaneously during extended AOTs and does not preclude
the practice. Therefore, since the current STS also allows separate
condition entry for each penetration flow path, the licensee's
application will provide supporting information that verifies that the
potential for any cumulative risk impact of failed PCIVs and multiple
PCIV extended AOT entries has been evaluated and is acceptable. The
licensee's Tier 3 configuration risk management program (10 CFR
50.65(a)(4)) must provide supporting information that confirms that
such simultaneous extended AOT entries for inoperable PCIVs in separate
penetration flow paths will not exceed the RG 1.174 and RG 1.177
acceptance guidelines, as confirmed by the analysis presented in TR
NEDC-33046, and that adequate defense-in-depth for safety systems is
maintained.
7. The licensee shall provide supporting information that verifies
that the plant-specific probabilistic risk assessment (PRA) quality is
acceptable for this application in accordance with the guidelines given
in RG 1.174. To ensure the applicability of TR NEDC-33046, to a
licensee's plant, additional information on PRA quality will be
required from each licensee requesting an amendment in the following
areas:
a. Justification that the plant-specific PRA reflects the as-built,
as-operated plant.
b. Applicable PRA updates including individual plant examinations/
individual plant examinations of external events (IPE/IPEEE) findings.
c. Conclusions of the peer review including any A or B facts and
observations (F and Os) applicable to the proposed PCIV extended CTs.
d. The PRA quality assurance program and associated procedures.
e. PRA adequacy, completeness, and applicability with respect to
evaluating the proposed PCIV extended AOT plant specific impact.
Commitment
1. The RG 1.177 Tier 3 program ensures that while the plant is in a
limiting condition for operation (LCO) condition with an extended AOT
for an inoperable PCIV, additional activities will not be performed
that could further degrade the capabilities of the plant to respond to
a condition the inoperable PCIV or system was designed to mitigate and,
as a result, increase plant risk beyond that assumed by the LTR
analysis. A licensee's implementation of RG 1.177 Tier 3 guidelines
generally implies the assessment of risk with respect to CDF. However,
the proposed PCIV AOT impacts containment isolation and consequently
LERF as well as CDF. Therefore, a licensee's configuration risk
management program (CRMP), including those implemented under the
maintenance rule of 10 CFR 50.65(a)(4), must be enhanced to include a
LERF methodology/assessment and must be documented in a licensee's
plant-specific submittal.
The CLIIP does not prevent licensees from requesting an alternative
approach or proposing the changes without providing the information
described in the above 7 conditions, or making the requested
commitment. 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 60 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 SE or
[[Page 30153]]
proposed 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.
Proposed Safety Evaluation
U.S. Nuclear Regulatory Commission
Office of Nuclear Reactor Regulation Consolidated Line Item Improvement
Technical Specification Task Force (TSTF) Change Traveler No. TSTF-454,
Revision 0, ``Increase PCIV Completion Times From 4 hours, 24 hours
[note that the 24-hour portion was withdrawn], and 72 hours to 7 days
(NEDC-33046)''
1.0 Introduction
By application dated [ ] , [Licensee] (the licensee) requested
changes to the Technical Specifications (TSs) for [facility]. The
proposed changes would revise TS 3.6.1.3, ``Primary Containment
Isolation Valves (PCIVs),'' by extending to 7 days the completion time
(CT) to restore an inoperable PCIV or isolate the affected penetration
flow path for selected primary containment penetrations with two (or
more) PCIVs and for selected primary containment penetrations with only
one PCIV.
2.0 Regulatory Evaluation
The existing Limiting Condition for Operation (LCO) 3.6.1.3,
requires that each PCIV be operable. The operability of PCIVs ensures
that the containment is isolated during a design-basis accident (DBA)
and is able to perform its function as a barrier to the release of
radioactive material. For boiling water reactor (BWR)/4 plants, if a
PCIV is inoperable in one or more penetrations, the current required
action is to isolate or restore the inoperable PCIV to operable status
within 4 hours for penetrations with 2 PCIVs (except for the main steam
line, in which case 8 hours is allowed), and within 4 hours for
penetrations with a single PCIV (except for excess flow check valves
(EFCVs) and penetrations with a closed system, and for other cases if
justified with a plant-specific evaluation, in which case 72 hours is
allowed). Regarding the leakage rate of EFCVs, 72 hours is also
currently allowed to restore EFCV leakage to within limit. For BWR/6
plants, the current required actions are the same as those for the BWR/
4 plants with the exception that there are no TSs for EFCVs. The times
specified for performing these actions were considered reasonable,
given the time required to isolate the penetration and the relative
importance of ensuring containment integrity during plant operation. In
the case of a single EFCV PCIV or a single PCIV and a closed system,
the specified CT takes into consideration the ability of the instrument
and the small pipe diameter (associated with the EFCV) or the closed
system to act as a penetration boundary.
On May 3, 2002, as supplemented by letter dated July 30, 2003, the
Boiling Water Reactor (BWR) Owners Group (BWROG) submitted the generic
Topical Report (TR) NEDC-33046, which provided a risk-informed
justification for extending the TS allowed outage time (AOT) (also
referred to as completion time), for a specific set of inoperable PCIVs
from the current 4 hours or 72 hours to 7 days. Specifically, for BWR/4
plants, if a PCIV is inoperable in one or more penetrations, the
proposed action is to isolate or restore the inoperable PCIV to
operable status within 7 days for penetrations with 2 PCIVs (except for
the feedwater isolation valves (FWIVs) and the residual heat removal
(RHR) shutdown cooling suction line PCIVs, in which case the 4 hours is
kept, and except for the main steam line isolation valves (MSIVs), in
which case the 8 hours is kept); and within 4 hours for penetrations
with a single PCIV, except for EFCVs and penetrations with a closed
system, in which case 7 days is allowed (and except for other cases if
justified with a plant-specific evaluation, in which case the 72 hours
is kept). Regarding the leakage rate of EFCVs, 7 days is also proposed
to restore EFCV leakage to within the limit. For BWR/6 plants, the
proposed actions are the same as those for the BWR/4 plants with the
exception that for penetrations with 2 PCIVs, there is an additional
exception to the 7-day AOT (for the low pressure core spray system
PCIVs, in which case the 4 hours is kept); and with the exception that
there are no TSs for EFCVs.
The NRC staff used the guidance of Regulatory Guide (RG) 1.174,
``An Approach for Using Probabilistic Risk Assessment in Risk-Informed
Decisions on Plant-Specific Changes to the Current Licensing Basis,
1998,'' and RG 1.177, ``An Approach for Plant-Specific, Risk-Informed
Decision Making: Technical Specifications, 1998,'' in performing its
review of this TR. RG 1.174 provides the guidelines to determine the
risk level associated with the proposed change. RG 1.177 provides a
three-tiered approach to evaluate the risks associated with proposed
license amendments. The first tier evaluates the probabilistic risk
assessment (PRA) model and the impacts of the changes on plant
operational risk. The second tier addresses the need to preclude
potentially high risk configurations, should additional equipment
outages occur during the AOT. The third tier evaluates the licensee's
configuration risk management program (CRMP) to ensure that the removal
of equipment from service immediately prior to or during the proposed
AOT will be appropriately assessed from a risk perspective. The NRC
staff's safety evaluation (SE) dated October 8, 2004, also discusses
the applicable regulations and additional applicable regulatory
criteria/guidelines that were considered in its review of TR NEDC-
33046.
3.0 Technical Evaluation
3.1 Statement of Proposed Changes
The proposed changes to TS 3.6.1.3 include:
1. For the Condition of one or more penetration flow paths with one
PCIV inoperable in a penetration flow path with two [or more] PCIVs,
the Completion Times for isolating the affected penetration (in
Standard Technical Specification (STS) 3.6.1.3 Required Action A.1) are
revised from ``4 hours except for main steam line AND 8 hours for main
steam line,'' to ``4 hours for feedwater isolation valves (FWIVs),
residual heat removal (RHR) shutdown cooling suction line PCIVs, and
Low Pressure Core Spray (LPCS) System PCIVs (NUREG-1434 only) AND 8
hours for main steam line isolation valves (MSIVs) AND 7 days except
for FWIVs, RHR shutdown cooling suction line PCIVs, LPCS System PCIVs
(NUREG-1434 only), and MSIVs.'' For PCIVs not analyzed in NEDC-33046
(i.e., FWIVs and MSIVs), the current Completion Times of 4 hours and 8
hours (of STS 3.6.1.3 Required Action A.1) are maintained; 4 hours for
FWIVs and 8 hours for main steam lines (i.e., MSIVs as described in the
current Bases for STS 3.6.1.3 Required Action A.1). For PCIVs analyzed
in NEDC-33046 that did not meet the criterion for extension (i.e., RHR
shutdown cooling suction line PCIVs (for all BWRs) and LPCS System
PCIVs (for BWR/5 and BWR/6 designs only), the current Completion Time
(of 4 hours of STS 3.6.1.3 Required Action A.1) is maintained. The
Completion
[[Page 30154]]
Time for other PCIVs, associated with penetrations with two [or more]
PCIVs, is extended to 7 days.
2. For the Condition of one or more penetration flow paths with one
PCIV inoperable in a penetration flow path with only one PCIV, the
Completion Times for isolating the affected penetrations (STS 3.6.1.3
Required Action C.1) are revised from ``4 hours except for excess flow
check valves (EFCVs) and penetrations with a closed system AND 72 hours
for EFCVs and penetrations with a closed system,'' to ``4 hours except
for excess flow check valves (EFCVs) and penetrations with a closed
system AND [72 hours] [7 days] for EFCVs and penetrations with a closed
system.'' (For NUREG-1434, the Completion Times for STS 3.6.1.3
Required Action C.1 are revised from ``4 hours except for penetrations
with a closed system AND 72 hours for penetrations with a closed
system,'' to ``4 hours except for penetrations with a closed system AND
[72 hours] [7 days] for penetrations with a closed system.'')
3. For the Condition of one or more [secondary containment bypass
leakage rate,] [MSIV leakage rate,] [purge valves leakage rate,]
[hydrostatically tested line leakage rate,] [or] [EFCV leakage rate]
not within limit, the Completion Time for restoring leakage rate to
within limit, when the leakage rate exceeded is the EFCV leakage rate
(in STS 3.6.1.3 Required Action D.1), is revised from ``[72 hours]'' to
``[7 days]'' by adding a new Completion Time, ``[AND 7 days for EFCV
leakage].'' (The EFCV leakage rate Completion Time change is not
applicable to NUREG-1434.)
3.2 Evaluation of Proposed Changes
The NRC staff's SE on TR NEDC-33046, dated October 8, 2004, found
that based on the use of bounding risk parameters for General Electric
(GE)-designed plants, for the proposed increase in the PCIV AOT from 4
hours (for penetrations with 2 or more PCIVs) or 72 hours (for
penetrations with a single EFCV PCIV, and penetrations with a single
PCIV and a closed system) or 72 hours (for EFCV leakage) to 7 days, the
risk impact of the proposed 7-day AOT for the PCIVs as estimated by
core damage frequency (CDF), large early release frequency (LERF),
incremental conditional core damage probability (ICCDP), and
incremental conditional large early release probability (ICLERP), is
consistent with the acceptance guidelines specified in RG 1.174, RG
1.177, and NRC staff guidance outlined in Chapter 16.1 of NUREG-0800.
The NRC staff found that the risk analysis methodology and approach
used by the BWROG to estimate the risk impacts were reasonable and of
sufficient quality.
The NRC staff's October 8, 2004, SE also found the following. The
Tier 2 evaluation did not identify any risk-significant plant equipment
configurations requiring TS, procedure, or compensatory measures. TR
NEDC-33046 implements a CRMP (Tier 3) using 10 CFR 50.65(a)(4) to
manage plant risk when PCIVs are taken out-of-service. PCIV reliability
and availability will also be monitored and assessed under the
maintenance rule (10 CFR 50.65) to confirm that performance continues
to be consistent with the analysis assumptions used to justify extended
PCIVs AOTs.
The NRC staff's October 8, 2004, SE also found that the following
conditions and commitment must be addressed by licensees adopting TR
NEDC-33046 in plant-specific applications that seek approval of TSTF-
454, Revision 0 for their plants:
Conditions
1. Because not all penetrations have the same impact on core damage
frequency (CDF), large early release frequency (LERF), incremental
conditional core damage frequency (ICCDP), or incremental conditional
large early release frequency (ICLERP), a licensee's application must
provide supporting information that verifies the applicability of TR
NEDC-33046, including verification that the PCIV configurations for the
specific plant match the licensing topical report (LTR) and the risk
parameter values used in the LTR are bounding for the specific plant.
Any additional PCIV configurations or non-bounding risk parameter
values not evaluated by the LTR should be included in the licensee's
plant-specific analysis. [Note that PCIV configurations or non-bounding
risk parameter values outside the scope of the LTR will require NRC
staff review of the specific penetrations and related justifications
for the proposed CTs.]
2. The licensee's application must provide supporting information
that verifies that external event risk, either through quantitative or
qualitative evaluation, will not have an adverse impact on the
conclusions of the plant-specific analysis for extending the PCIV AOTs.
3. Because TR NEDC-33046 was based on generic plant
characteristics, each licensee adopting the TR must provide supporting
information that confirms plant-specific Tier 3 information in their
individual submittals. The licensee's application must provide
supporting information that discusses the conformance to the
requirements of the maintenance rule (10 CFR 50.65(a)(4)), as they
relate to the proposed PCIV AOTs and the guidance contained in NUMARC
93.01, Section 11, as endorsed by Regulatory Guide (RG) 1.182,
including verification that the licensee's maintenance rule program,
with respect to PCIVs, includes a LERF/ICLERP assessment as part of the
maintenance rule process.
4. The licensee's application must provide supporting information
that verifies that a penetration remains intact during maintenance
activities, including corrective maintenance activities. Regarding
maintenance activities where the pressure boundary would be broken, the
licensee must provide supporting information that confirms that the
assumptions and results of the LTR remain valid. This includes the
assumption that maintenance on a PCIV will not break the pressure
boundary for more than the currently allowed AOT.
5. The licensee's application must provide supporting information
that verifies the operability of the remaining PCIVs in the associated
penetration flow path before entering the AOT for the inoperable PCIV.
6. Simultaneously entering the extended AOT for multiple PCIVs and
the resulting impact on risk were not specifically evaluated by the
BWROG. However, TR NEDC-33046 does state that multiple PCIVs can be out
of service simultaneously during extended AOTs and does not preclude
the practice. Therefore, since the current STS also allows separate
condition entry for each penetration flow path, the licensee's
application will provide supporting information that verifies that the
potential for any cumulative risk impact of failed PCIVs and multiple
PCIV extended AOT entries has been evaluated and is acceptable. The
licensee's Tier 3 configuration risk management program (10 CFR
50.65(a)(4)) must provide supporting information that confirms that
such simultaneous extended AOT entries for inoperable PCIVs in separate
penetration flow paths will not exceed the RG 1.174 and RG 1.177
acceptance guidelines, as confirmed by the analysis presented in TR
NEDC-33046, and that adequate defense-in-depth for safety systems is
maintained.
7. The licensee shall provide supporting information that verifies
that the plant-specific probabilistic risk assessment (PRA) quality is
acceptable for this application in accordance with the guidelines given
in RG 1.174. To ensure the applicability of TR NEDC-33046, to a
licensee's plant, additional information on PRA quality will be
[[Page 30155]]
required from each licensee requesting an amendment in the following
areas:
a. Justification that the plant-specific PRA reflects the as-built,
as-operated plant.
b. Applicable PRA updates including individual plant examinations/
individual plant examinations of external events (IPE/IPEEE) findings.
c. Conclusions of the peer review including any A or B facts and
observations (F and Os) applicable to the proposed PCIV extended CTs.
d. The PRA quality assurance program and associated procedures.
e. PRA adequacy, completeness, and applicability with respect to
evaluating the proposed PCIV extended AOT plant specific impact.
Commitment
1. The RG 1.177 Tier 3 program ensures that while the plant is in a
limiting condition for operation (LCO) condition with an extended AOT
for an inoperable PCIV, additional activities will not be performed
that could further degrade the capabilities of the plant to respond to
a condition the inoperable PCIV or system was designed to mitigate and,
as a result, increase plant risk beyond that assumed by the LTR
analysis. A licensee's implementation of RG 1.177 Tier 3 guidelines
generally implies the assessment of risk with respect to CDF. However,
the proposed PCIV AOT impacts containment isolation and consequently
LERF as well as CDF. Therefore, a licensee's configuration risk
management program (CRMP), including those implemented under the
maintenance rule of 10 CFR 50.65(a)(4), must be enhanced to include a
LERF methodology/assessment and must be documented in a licensee's
plant-specific submittal.
Staff Findings
The NRC staff has reviewed the proposed TS changes and finds that
they are consistent with previous staff reviews of TR NEDC-33046 as
supplemented by letter dated July 30, 2003, and as approved by the NRC
by letter and Safety Evaluation dated October 8, 2004, and TSTF-454,
Revision 0, and are acceptable. The NRC staff has also reviewed the
licensee's supporting information and the statements regarding the
above conditions and commitment and finds them acceptable. Therefore,
the NRC staff finds that the increase in the CTs from 4 hours (for
penetrations with 2 or more PCIVs) or 72 hours (for penetrations with a
single EFCV PCIV, and penetrations with a single PCIV and a closed
system) or 72 hours (for EFCV leakage) to 7 days is justified.
4.0 Regulatory Commitment
The licensee's letter dated [ ], contained the following regulatory
commitment:
[State the licensee's commitment and ensure that it satisfies the
commitment in this SE, in Section 3.2 above.]
The NRC staff finds that reasonable controls for the implementation
and for subsequent evaluation of proposed changes pertaining to the
above regulatory commitment are best provided by the licensee's
administrative processes, including its commitment management program.
The above regulatory commitment does not warrant the creation of a
regulatory requirement (item requiring prior NRC approval of subsequent
changes).
5.0 State Consultation
In accordance with the Commission's regulations, the [State] State
official was notified of the proposed issuance of the amendments. The
State official had [choose one: (1) No comments, or (2) the following
comments--with subsequent disposition by the staff].
6.0 Environmental Consideration
The amendment changes 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 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 (XX FR XXXXX). 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.
7.0 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 the 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: The proposed amendment extends
the completion time (CT) for penetration flow paths with one valve
inoperable from 4 hours or 72 hours to 7 days. The change is applicable
to both primary containment penetrations with two (or more) primary
containment isolation valves (PCIVs) and with one PCIV. This change is
not applicable to the feedwater isolation valves (FWIVs), the residual
heat removal (RHR) shutdown cooling suction line PCIVs, the low
pressure core spray (LPCS) PCIVs (boiling water reactor (BWR)/6 only),
the main steam isolation valves (MSIVs), and [list of plant-specific
valves].
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:
1. Does the proposed change involve a significant increase in the
probability or consequences of an accident previously evaluated?
Response: No.
The proposed changes does not involve a significant increase in the
probability or consequences of an accident previously evaluated. The
proposed changes revise the completion times (CTs) for restoring an
inoperable primary containment isolation valve (PCIV) (or isolating the
affected penetration) within the scope of the Boiling Water Reactor
(BWR) Owners Group (BWROG) Topical Report (TR) NEDC-33046, ``Technical
Justification to Support Risk-Informed Primary Containment Isolation
Valve AOT [Allowed Outage Time] Extensions for BWR Plants,'' submitted
on May 3, 2002, as supplemented by letter dated July 30, 2003, and as
approved by the NRC by letter and Safety Evaluation (SE) dated October
8, 2004, from 4 hours or 72 hours to 7 days. PCIVs are not accident
initiators in any accident previously evaluated. Consequently, the
probability of an accident previously evaluated is not significantly
increased.
PCIVs, individually and in combination, control the extent of
leakage from the primary containment following an accident. The
proposed CT extensions apply to the reduction in redundancy in the
primary containment isolation function by the PCIVs for a limited
period of time, but do not alter the ability of the plant to meet the
overall primary containment leakage
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requirements. In order to evaluate the proposed CT extensions, a
probabilistic risk assessment (PRA) evaluation was performed in TR
NEDC-33046, submitted on May 3, 2002, as supplemented by letter dated
July 30, 2003, and as approved by the NRC by letter and SE dated
October 8, 2004. The PRA evaluation concluded that, based on the use of
bounding risk parameters for the General Electric (GE)-designed plants,
the proposed increase in the PCIV CTs from 4 hours or 72 hours to 7
days does not alter the ability of the plant to meet the overall
primary containment leakage requirements. It also concluded that the
proposed changes do not result in an unacceptable incremental
conditional core damage probability (ICCDP) or incremental conditional
large early release probability (ICLERP) according to the guidelines of
Regulatory Guide (RG) 1.177. As a result, there would be no significant
increase in the consequences of an accident previously evaluated.
Therefore, the proposed changes do not involve a significant increase
in the probability or consequences of an accident previously evaluated.
2. Does the change create the possibility of a new or different
kind of accident from any accident previously evaluated?
Response: No.
The proposed change does not create the possibility of a new or
different kind of accident from any accident previously evaluated. The
proposed changes revise the CTs for restoring an inoperable PCIV (or
isolating the affected penetration) within the scope of TR NEDC-33046
submitted on May 3, 2002, as supplemented by letter dated July 30,
2003, and as approved by the NRC by letter and Safety Evaluation dated
October 8, 2004, from 4 hours or 72 hours to 7 days. PCIVs,
individually and in combination, control the extent of leakage from the
primary containment following an accident. The proposed CT extensions
apply to the reduction in redundancy in the primary containment
isolation function by the PCIVs for a limited period of time, but do
not alter the ability of the plant to meet the overall primary
containment leakage requirements. The proposed changes do not change
the design, configuration, or method of operation of the plant. The
proposed changes do not involve a physical alteration of the plant (no
new or different type of equipment will be installed). Therefore, the
proposed changes do not create the possibility of a new or different
kind of accident from any previously evaluated.
3. Does the proposed change involve a significant reduction in a
margin of safety?
Response: No.
The proposed change does not involve a significant reduction in a
margin of safety. The proposed changes revise the CTs for restoring an
inoperable PCIV (or isolating the affected penetration) within the
scope of the TR NEDC-33046 submitted on May 3, 2002, as supplemented by
letter dated July 30, 2003, and as approved by the NRC by letter and SE
dated October 8, 2004, from 4 hours or 72 hours to 7 days. PCIVs,
individually and in combination, control the extent of leakage from the
primary containment following an accident. The proposed CT extensions
apply to the reduction in redundancy in the primary containment
isolation function provided by the PCIVs for a limited period of time,
but do not alter the ability of the plant to meet the overall primary
containment leakage requirements. In order to evaluate the proposed CT
extensions, a PRA evaluation was performed in TR NEDC-33046 submitted
on May 3, 2002, as supplemented by letter dated July 30, 2003, and as
approved by the NRC by letter and SE dated October 8, 2004. The PRA
evaluation concluded that, based on the use of bounding risk parameters
for GE-designed plants, the proposed increase in the PCIV CTs from 4
hours or 72 hours to 7 days does not alter the ability of the plant to
meet the overall primary containment leakage requirements. It also
concluded that the proposed changes do not result in an unacceptable
ICCDP or ICLERP according to the guidelines of RG 1.177. Therefore, the
proposed changes do not involve a significant reduction in a margin of
safety.
Based on the above, the proposed change involves no significant
hazards consideration under the standards set forth in 10 CFR 50.92(c),
and accordingly, a finding of no significant hazards consideration is
justified.
Dated at Rockville, Maryland, this 19th day of May, 2005.
For the Nuclear Regulatory Commission.
Herbert N. Berkow,
Director, Project Directorate IV, Division of Licensing Project
Management, Office of Nuclear Reactor Regulation.
[FR Doc. E5-2631 Filed 5-24-05; 8:45 am]
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