[Federal Register Volume 70, Number 238 (Tuesday, December 13, 2005)]
[Notices]
[Pages 73802-73809]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E5-7272]
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NUCLEAR REGULATORY COMMISSION
Notice of Availability of Model Application Concerning Technical
Specification Improvement To Extend the Completion Times for Inoperable
Containment Isolation Valves at General Electric Plants 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 application relating
to changes to the Standard Technical Specifications (STSs) 3.6.1.3,
``Primary Containment Isolation Valves (PCIVs),'' for boiling-water
reactors (BWR) in NUREG-1433, Revision 3, ``Standard Technical
Specifications, General Electric Plants, BWR/4,'' and ``NUREG-1434,
Revision 3, ``Standard Technical Specifications, General Electric
Plants, BWR/6.'' The proposed change to the STSs 3.6.1.3 would extend
to 7 days the completion time (CT) (or allowed outage time (AOT)) to
restore an inoperable PCIV to operable status or isolate the affected
penetration flow path both 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 BWR
Owners' Group (BWROG). The BWROG, through its participation in the
Technical Specification (TS) Task Force (TSTF) proposed this change to
the STSs in Change Traveler No. TSTF-454, Revision 1. This notice also
includes a model safety evaluation (SE) and 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 TSs
for General Electric (GE) 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 provide supporting documentation
to confirm the applicability of the SE and NSHC determination to its
plant.
DATES: The NRC staff issued a Federal Register Notice (70 FR 30151, May
25, 2005) which provided a model SE and a model NSHC determination
relating to the extension of the CT for TS actions related to
inoperable PCIVs at GE plants. The NRC staff hereby announces that the
model SE and NSHC determination may be referenced in plant-specific
applications to extend the PCIV completion times as described in
Revision 1 to TSTF-454. 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 request the subject TS 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: Bhalchandra Vaidya, Mail Stop: O-7D1,
Division of Operating Reactor Licensing, 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 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
STSs in a manner that supports subsequent license amendment
applications. The CLIIP includes an opportunity for the public to
comment on proposed changes to the STSs, 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 STSs 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 to operable status 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, including
corresponding changes to the TS Bases, for incorporation into the STSs
as TSTF-454, Revision 0. By letter dated September 21, 2005, BWROG
revised the proposed change as TSTF-454, Revision 1. This change is
based on the NRC staff-approved generic analyses contained in BWROG TR
NEDC-33046-A, ``Technical Justification to Support Risk-Informed
Primary Containment Isolation Valve AOT Extensions for BWR Plants,''
transmitted to the NRC on January 20, 2005, which is accessible
electronically from the Agencywide Documents Access and Management
System's (ADAMS) Public Electronic Reading Room on the Internet (ADAMS
Accession No. ML050240360) at the NRC Web site http://www.nrc.gov/reading-rm/adams.html. This transmittal incorporated TR NEDC-33046,
submitted on May 3, 2002 (ADAMS Accession No. ML021280156), as
supplemented by letter dated July 30, 2003 (ADAMS Accession No.
ML032130164), and as approved by the NRC in its letter and SE dated
October 8, 2004 (ADAMS Accession No. ML042660055). 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 GE BWRs.
To efficiently process the incoming license amendment applications,
the NRC staff requests each licensee applying for the changes addressed
by TSTF-454, Revision 1, to use the CLIIP to address the seven plant-
specific conditions and the one commitment identified in the model SE,
as follows:
[[Page 73803]]
Conditions
1. Because not all penetrations have the same impact on core damage
frequency (CDF), large early release frequency (LERF), incremental
conditional core damage probability (ICCDP), or incremental conditional
large early release probability (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 TR and that the risk parameter values used in
the TR are bounding for the specific plant. Any additional PCIV
configurations or non-bounding risk parameter values not evaluated by
the TR 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 TR 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 CTs.
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 CTs and the guidance contained in NUMARC 93-01, Section
11, as endorsed by Regulatory Guide (RG) 1.182, ``Assessing and
Managing Risk Before Maintenance Activities at Nuclear Power Plants.''
This should include verification that the licensee's maintenance rule
program, with respect to PCIVs, includes a LERF and 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 TR remain valid. This includes the
assumption that maintenance on a PCIV will not break the pressure
boundary for more than the currently allowed CT.
5. The licensee's application must provide supporting information
that it will verify the operability of the remaining PCIVs in the
associated penetration flow path before applying an extended CT for an
inoperable PCIV.
6. Simultaneously utilizing the proposed extended CT for multiple
inoperable 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 CTs and does
not preclude the practice. Therefore, the licensee's application must
provide supporting information that confirms that its Tier 3
configuration risk management program (10 CFR 50.65(a)(4)) requires
that simultaneous application of an extended CT to more than one
inoperable PCIV in separate penetration flow paths is evaluated. The
purpose of this evaluation is to ensure that the cumulative risk of
continued plant operation with multiple inoperable PCIVs utilizing
extended CTs does not exceed the plant risk value, as determined by the
analysis presented in TR NEDC-33046.
7. The licensee must 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, ``An Approach for Using Probabilistic Risk Assessment in
Risk-Informed Decisions on Plant-specific Changes to the Licensing
Basis.'' To ensure the applicability of TR NEDC-33046 to a licensee's
plant, each licensee requesting an amendment must provide additional
information on PRA quality 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
(IPE) and individual plant examinations of external events (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 plant specific impact of the proposed PCIV extended CT.
Commitment
The RG 1.177, ``An Approach for Plant-Specific, Risk-Informed
Decisionmaking: Technical Specifications,'' Tier 3 program ensures
that, while the plant is in a limiting condition for operation (LCO)
actions condition with an extended CT for restoring an inoperable PCIV
to operable status, additional activities will not be performed that
could further degrade the capabilities of the plant to respond to a
condition the inoperable PCIV or associated system is designed to
mitigate and, as a result, increase plant risk beyond that determined
by the TR 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 extended CT impacts containment
isolation and, consequently, LERF as well as CDF. Therefore, each
licensee requesting extended CTs for PCIVs under TSTF-454, Revision 1,
must commit to enhancing its configuration risk management program
(CRMP), including those implemented under 10 CFR 50.65(a)(4), the
maintenance rule, to include a LERF methodology and assessment. This
commitment and the CRMP enhancements must be documented in the
licensee's plant-specific application.
The CLIIP does not prevent licensees from requesting an alternative
approach or proposing the changes without providing the information
described in the above seven 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
In a notice published in the Federal Register dated May 25, 2005
(70 FR 30151), the NRC staff requested comment on the use of the CLIIP
to process requests to extend the CT for selected inoperable PCIVs at
GE plants, as described in Revision 0 of TSTF-454.
TSTF-454, Revision 1, 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 O-1 F21, 11555 Rockville Pike (first floor), Rockville, Maryland.
Publicly available records are accessible electronically from the ADAMS
Public Library component on the NRC Web site, (the Electronic Reading
Room).
In response to the notice soliciting comments from interested
members of the public about modifying the TS requirements regarding an
increase in the specified CTs to restore an inoperable PCIV to operable
status or
[[Page 73804]]
isolate the affected penetration flow path when selected PCIVs are
inoperable at BWRs, the NRC staff received three comments from the
Owners Group TSTF members. These comments were specific to the model SE
and are discussed as follows:
Comment 1 (as stated)
Condition 3, Condition 6, and the one required commitment of
Section 3.2, Evaluation of Proposed Changes, of the model Safety
Evaluation are not clear or consistent on the expectations for a
containment performance assessment (i.e., large early release fraction
[should be ``frequency''], or LERF) as part of the configuration risk
management program (CRMP). These conditions should be clarified either
in the Safety Evaluation or in the CLIIP model application.
Condition 3 requires licensees to conform to the Maintenance Rule
requirements of 10 CFR 50.65(a)(4), as it relates to Primary
Containment Isolation Valve (PCIV) Completion Times and the guidance of
NUMARC 93-01, ``Industry Guideline for Monitoring the Effectiveness of
Maintenance at Nuclear Power Plants,'' Section 11, including a LERF and
incremental conditional large early release probability (ICLERP)
assessment as part of the process. In addition, Condition 6 requires
the CRMP to confirm that simultaneous extended Completion Time entries
in separate penetration flow paths will not exceed the Regulatory Guide
1.174 and Regulatory Guide 1.177 acceptance guidelines. The commitment
required by the Safety Evaluation also requires the licensee's CRMP be
enhanced to include a LERF methodology and assessment.
Many licensees do not currently have a probabilistic risk
assessment (PRA) Level 2 model built into the CRMP for calculating a
LERF risk value. Adding the LERF model will significantly delay
adoption of the proposed Traveler [TSTF-454]. The containment risk
management assessment is routinely addressed through qualitative
methods and administrative controls. Section 11 of NUMARC 93-01 allows
for qualitative assessment methods. Section 11.3.4, Assessment Methods
for Power Operating Conditions, states, ``Simultaneous removal from
service of multiple SSCs [structures, systems, and components] requires
that an assessment be performed using quantitative, qualitative, or
blended (quantitative and qualitative) methods.'' Sections 11.3.4.1 and
11.3.4.2 provide guidance regarding quantitative and qualitative
considerations, respectively.
Is it the intent of the conditions and commitment to require a PRA
calculation to quantify LERF risk values for the specific plant
configurations each time a PCIV is inoperable? Would this apply only
when the extended Completion Time is used or only when multiple
penetration flow paths are affected as discussed in Condition 6? Would
it be acceptable to assess and manage the containment performance
impacts by qualitative methods and administrative controls as currently
allowed by NUMARC 93-01 as endorsed by Regulatory Guide 1.182? For
example, an assessment program could manage containment performance
risk by limiting the number of affected penetration flow paths
depending on factors such as the flow path size and not require a LERF
calculation for each occurrence.
Response to Comment 1
The BWROG states that many licensee's do not have a level 2 PRA
model built into the CRMP for calculating LERF. The BWROG further
states that adopting a LERF model will significantly delay
implementation of the proposed TSTF traveler. The BWROG references
Sections 11.3.4.1 and 11.3.4.2 of NUMARC 93-01 for both quantitative
and qualitative risk assessment methods in the evaluation of Tier 3.
Although they are inter-related, the following questions were
identified in BWROG Comment 1 concerning Conditions 3 and 6 of the
staff model SE issued for comment on May 25, 2005 (70 FR 30151).
1. Is it the intent of the conditions and commitment to require a
PRA calculation to quantify the LERF risk values for the specific plant
configurations each time a PCIV is inoperable?
2. Would this apply only when the extended CT is used or only when
multiple penetration flow paths are effected as discussed in Condition
6?
3. Would it be acceptable to assess and manage the containment
performance impacts by qualitative methods and administrative controls
as currently allowed by NUMARC 93-01, endorsed by RG 1.182?
Condition 3 of the model SE is intended to ensure that a licensee's
CRMP includes a LERF and an ICLERP assessment for PCIVs as part of the
CRMP and maintenance rule process. The intent of the conditions and
commitment is to ensure an assessment of risk for the actual resulting
plant configuration when a PCIV is inoperable. The concerns of the NRC
staff are that PCIVs affect risk mainly through LERF, and that CRMP
evaluations performed as part of Tier 3 may not address LERF in the
risk evaluation. An additional concern of the NRC staff stems from the
fact that TR NEDC-33046 only evaluated the risk of extending the CT for
a single PCIV. However, the implementation of the TR allows separate
concurrent extended CTs for multiple inoperable PCIVs because the
current and proposed STSs for extended PCIVs allow separate actions
condition entry for each penetration flow path (see the NRC staff's
response to Comment 2). As stated by the BWROG in its comment, many
licensees do not have a PRA level 2 model incorporated into the CRMP
for the evaluation of LERF. The intent of Condition 3 is to ensure that
Tier 3 evaluations of both CDF and LERF are performed to assess PCIV
CTs when PCIVs are determined to be inoperable or taken out of service.
As stated in Condition 3 of the NRC staff model SE, a licensee's
application must provide supporting information that discusses the
plant's conformance to the requirements of the maintenance rule (10 CFR
50.65(a)(4)) and the guidance contained in NUMARC 93-01, Section 11, as
endorsed by RG 1.182. With respect to comment 1 in general, the NRC
staff cannot provide a definitive response without reviewing a plant-
specific approach. The assessment program chosen by a licensee or the
BWROG (qualitative, quantitative, or combination) must be documented in
the licensee's application because Tier 3 aspects of the proposed PCIV
CT extensions were not specifically addressed by TR NEDC-33046.
Therefore, the NRC staff does not believe that changes to Condition 3
are warranted.
Comment 2 (as Stated)
Condition 6 of Section 3.2, Evaluation of Proposed Changes,
requires the licensee's application to provide supporting information
that verifies that the potential for any cumulative risk impact of
failed PCIVs and multiple PCIV extended Completion Time entries has
been evaluated and is acceptable. The verb tense ``has been evaluated''
is confusing. Is [it] the intent to require an assessment of the
plant's design and historical experience to verify that the potential
for multiple extended Completion Time entries is low? Please clarify
either in the Safety Evaluation or in the CLIIP model application what
the evaluation involves.
Response to Comment 2
The following question was identified in BWROG Comment 2 concerning
Condition 6 of the staff model SE issued for comment on May 25, 2005
(70 FR 30151).
[[Page 73805]]
The verb tense ``has been evaluated'' is confusing. Is [it] the
intent of condition 6 to require an assessment of the plant's design
and historical experience to verify that the potential for multiple
concurrent use of extended Completion Times is low? Please clarify
in either the Safety Evaluation or the CLIIP model application what
the assessment should address.
Condition 6 is concerned with the Tier 3 analysis that provides
added assurance that the TR's conclusion that no risk significant
configurations will result from the proposed extended PCIV CTs remains
valid over extended periods of plant operation. However, in addition to
Condition 6, as stated in the NRC staff's TR SE, a licensee adopting TR
NEDC-33046 must confirm that the conclusions of the generic Tier 2
analysis are applicable to its facility.
As already stated, TR NEDC-33046 does not limit the number of PCIVs
that can concurrently but separately be in an actions condition with an
extended CT because the PCIV TS actions allow separate condition entry
for each penetration flow path. The intent of Condition 6 is to ensure
that, for multiple concurrently inoperable PCIVs, including those
utilizing extended CTs, the licensee will evaluate the impact on risk
to verify that the conditions of TR NEDC-33046 remain satisfied. As
stated in Condition 3 of the NRC staff's model SE, a licensee's
application to adopt TSTF-454, Revision 1, must provide supporting
information that discusses the plant's CRMP and inoperable PCIV
assessment program, the plant's conformance to the requirements of the
maintenance rule (10 CFR 50.65(a)(4)), and the guidance contained in
NUMARC 93-01, Section 11, as endorsed by RG 1.182 for the assessment of
risk, including LERF and ICLERP resulting from PCIV maintenance.
Based on the above, the staff will revise Condition 6 of the model
SE to clarify the applicability to Tier 3 CRMP as follows:
(6) Simultaneously utilizing the proposed extended CT for
multiple inoperable 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 CTs and does not preclude the practice. Therefore,
the licensee's application must provide supporting information that
confirms that its Tier 3 configuration risk management program (10
CFR 50.65(a)(4)) requires that simultaneous application of an
extended CT to more than one inoperable PCIV in separate penetration
flow paths is evaluated. The purpose of this evaluation is to ensure
that the cumulative risk of continued plant operation with multiple
inoperable PCIVs utilizing extended CTs does not exceed the plant
risk value, as determined by the analysis presented in TR NEDC-
33046.
Comment 3 (as stated)
Condition 1 of Section 3.2, Evaluation of Proposed Changes, uses
the terms ``incremental conditional core damage frequency (ICCDP)'' and
``incremental conditional large early release frequency (ICLERP).'' The
word ``frequency'' in these two terms should be changed to
``probability.''
Response to Comment 3
The staff agrees. The editorial errors for definitions of
incremental conditional core damage frequency (ICCDP) and incremental
conditional large early release frequency (ICLERP) will be corrected in
the model SE.
Other Changes to the Notice of Opportunity To Comment, Published in the
Federal Register Dated May 25, 2005 (70 FR 30151)
In addition to the changes mentioned in the above discussion of
comments, editorial changes, such as consistent use of ``TR'' in place
of ``LTR,'' use of ``CT'' in place of ``AOT,'' etc., have been made
without altering the original intent to the Notice of Opportunity for
Comments published in the Federal Register dated May 25, 2005 (70 FR
30151).
As described in the model application prepared by the NRC staff,
licensees may reference in their plant-specific applications for
adopting this change to STSs, the model SE, model NSHC determination,
and the environmental consideration in this ``Notice of Availability''
published in the Federal Register.
Model 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 1, ``Extend PCIV Completion Times (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 to operable status or to 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
BWR Owners Group (BWROG) submitted the generic Topical Report (TR)
NEDC-33046, ``Technical Justification to Support Risk-Informed Primary
Containment Isolation Valve AOT [Allowed Outage Time] Extensions for
BWR Plants,'' which provided a risk-informed justification for
extending the TS AOT (also referred to as CT), 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
[[Page 73806]]
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 CT (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,
November 2002'' and RG 1.177, ``An Approach for Plant-Specific, Risk-
Informed Decision Making: Technical Specifications, August 1998,'' in
performing its review of this TR. RG 1.174 provides the guidelines to
determine the risk 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 CT. 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
CT 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 and guidelines that were considered in its review of TR NEDC-
33046. By letter dated January 20, 2005, BWROG transmitted TR NEDC-
33046-A to NRC, which incorporated the TR NEDC-33046, submitted on May
3, 2002, as supplemented by letter dated July 30, 2003, and as approved
by the NRC in a letter and SE dated October 8, 2004.
3.0 Technical Evaluation
3.1 Statement of Proposed Changes
The proposed changes to STS 3.6.1.3 for BWR/4 and BWR/6 plants, as
approved in TSTF-454, Revision 1, 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-A
(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-A 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 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 [7days] 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 [7days] 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, for NUREG-1433, 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 for hydrostatically tested line leakage [on a closed
system] [and EFCV leakage]]'' to ``[72 hours for hydrostatically tested
line leakage [on a closed system] [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 CT 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 CT 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,
``Standard Review Plan.'' 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 TSs, 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 CTs.
3.2.1 Conditions and Commitment
The NRC staff's October 8, 2004, SE also found that certain
conditions and a commitment must be addressed by licensees adopting TR
NEDC-33046 (or TR NEDC-33046-A transmitted to NRC by letter dated
January 20, 2005) in plant-specific applications. These conditions and
the commitment, as clarified herein, that must be addressed
[[Page 73807]]
by licensees adopting TR NEDC-33046-A in plant-specific applications
that seek approval of TSTF-454, Revision 1, for their plants, are as
follows:
3.2.1.1 Conditions
1. Because not all penetrations have the same impact on CDF, LERF,
ICCDP, or 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 TR and that the risk parameter values used in the TR are bounding
for the specific plant. Any additional PCIV configurations or non-
bounding risk parameter values not evaluated by the TR 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 TR 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 CTs.
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 CTs and the guidance contained in NUMARC 93-01, Section
11, as endorsed by RG 1.182, ``Assessing and Managing Risk Before
Maintenance Activities at Nuclear Power Plants.'' This should include
verification that the licensee's maintenance rule program, with respect
to PCIVs, includes a LERF and 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 TR remain valid. This includes the
assumption that maintenance on a PCIV will not break the pressure
boundary for more than the currently allowed CT.
5. The licensee's application must provide supporting information
that it will verify the operability of the remaining PCIVs in the
associated penetration flow path before applying an extended CT for an
inoperable PCIV.
6. Simultaneously utilizing the proposed extended CT for multiple
inoperable 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 CTs and does
not preclude the practice. Therefore, the licensee's application must
provide supporting information that confirms that its Tier 3 CRMP (10
CFR 50.65(a)(4)) requires that simultaneous application of an extended
CT to more than one inoperable PCIV in separate penetration flow paths
is evaluated. The purpose of this evaluation is to ensure that the
cumulative risk of continued plant operation with multiple inoperable
PCIVs utilizing extended CTs does not exceed the plant risk value, as
determined by the analysis presented in TR NEDC-33046.
7. The licensee must 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, ``An Approach for using Probabilistic Risk Assessment in
Risk-Informed Decisions on Plant-specific Changes to the Licensing
Basis.'' To ensure the applicability of TR NEDC-33046 to a licensee's
plant, each licensee requesting an amendment must provide additional
information on PRA quality 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
(IPE) and individual plant examinations of external events (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 plant specific impact of the proposed PCIV extended CT.
3.2.1.2 Commitment
The RG 1.177 Tier 3 program ensures that, while the plant is in a
LCO actions condition with an extended CT for restoring an inoperable
PCIV to operable status, additional activities will not be performed
that could further degrade the capabilities of the plant to respond to
a condition the inoperable PCIV or associated system is designed to
mitigate and, as a result, increase plant risk beyond that determined
by the TR 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 extended CT impacts containment
isolation and, consequently, LERF as well as CDF. Therefore, each
licensee requesting extended CTs for PCIVs under TSTF-454, Revision 1,
must commit to enhancing its CRMP, including those implemented under 10
CFR 50.65(a)(4), the maintenance rule, to include a LERF methodology
and assessment. This commitment and the CRMP enhancements must be
documented in the licensee's plant-specific application.
3.3 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,
submitted by letter dated 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, which are incorporated in TR NEDC-33046-A, transmitted
to NRC by letter dated January 20, 2005, and TSTF-454, Revision 1, 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
license condition (item requiring prior NRC approval of subsequent
changes).
[[Page 73808]]
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, dated Month DD, YYYY]).
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.
Model 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 change revises 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-A, ``Technical Justification to Support Risk-Informed Primary
Containment Isolation Valve AOT [Allowed Outage Time] Extensions for
BWR Plants,'' transmitted to NRC by letter dated January 20, 2005, from
4 hours and 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. As such,
PCIVs are instrumental in controlling the consequences of an accident.
However, the consequences of any accident previously evaluated are no
different during the proposed extended CTs than during the existing
CTs. As a result, there would be no significant increase in the
consequences of an accident previously evaluated. Therefore, the
proposed change does 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 NEDC-33046-A,
transmitted to NRC by letter dated January 20, 2005, from 4 hours and
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 change
does not alter the design, configuration, or method of operation of the
plant. The proposed change does not involve a physical alteration of
the plant and no new or different type of equipment will be installed.
Therefore, the proposed change does 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 change revises the CTs for restoring an
inoperable PCIV or isolating the affected penetration within the scope
of the NEDC-33046-A, transmitted to NRC by letter dated January 20,
2005, from 4 hours and 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
change does not involve a significant reduction in a margin of safety.
Based on the above, the proposed change presents 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 4th day of December, 2005.
[[Page 73809]]
For the Nuclear Regulatory Commission.
David Terao,
Chief, Plant Licensing Branch G, Division of Operating Reactor
Licensing, Office of Nuclear Reactor Regulation.
[FR Doc. E5-7272 Filed 12-12-05; 8:45 am]
BILLING CODE 7590-01-P