ML20034C739
| ML20034C739 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 04/26/1990 |
| From: | PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | |
| Shared Package | |
| ML19302E091 | List: |
| References | |
| NUDOCS 9005070174 | |
| Download: ML20034C739 (9) | |
Text
.
i l
ATTACHMENT 1 I
l i
i
?
LIMERICK GENERATING STATION UNITS 1 and 2
)
Docket Nos. 50-352 50-353 i
f.icense Nos. NPF-39 hPF-85 I
TECHNICAL SPECIFICATIONS CHANGE REQUEST i
I t
" Reduced Testing of Reactor Protection System.
Emergency Core Cooling System and Common Instrumentation" l
i Supporting Infonnation for Changes - 7 pages i
e 1
t l
9005070174 900426 PDR ADOCK 05000352 P
PDC 4
l.
Docket Nos, 50-352 i
50-353 License Nos. NPF-39 NPF-85 Philadelphia Electric Company (PECo). Licensee under facility Operating Licenses NPf-39 and NPF-85 for Limerick Generating Station (LGS), Unit 1 and
)
Unit 2,respectively,herebyrequeststhattheTechnicalSpecifications(TS) contained in Appendix A of the Operating Licenses be amended as proposed herein to extend surveillance test intervals (STis) and allowable out-of-service times (A0Ts for the actuation instrumentation supporting Reactor Protection System (RPS)). Emergency Core Cooling System (ECCS), including instrumentation cos the Control Rod Block Function (CRBF), the Reactor Core Isolation Cooling (RCIC) system. End-of Cycle Recirculation Pump Trip (EOC-RPT) system, and the isolation instrumentation common to RPS and/or ECCS. The proposed changes will minimize unnecessary testing and remove excessively restrictive A0Ts that could potentially degrade overall plant safety and availability.
We request the changes proposed herein to be effective fifteen (15) days after issuance of the Amendments.
)
This Change Request provides a discussion and description of the i
proposed TS changes, a safety assessment of the proposed TS changes, information supporting a finding of No Significant Hazards Consideration, and information.
supporting an Environmental Assessment.
Discussion and Description of Proposed Changes Licensing Topical Report (LTR), "BWR Owners' Group Response to NRC Generic Letter 83-28, Item 4.5.3." (Reference 1) provided justification for the acceptability of current PPS STIs.
In addition Reference 1 established a basis for extending STis and A0Ts for RPS based on reliability analyses which estimate RPS failure frequency. The analyses were further developed in other LTRs (References 2 through 5) to provide justification for extending TS STIs and A0fs for the RPS and ECCS, including common instrumentation. References 2 through 5 also included proposed TS changes to facilitate implementation of the analyses results.
References 2 through 5 were submitted to the NRC by the Boiling Water Reactor Owners' Group (BWROG) and subsequently approved as detailed in NRC Safety Evaluation Reports (SERs) (References 6 through 10). These SERs describe the acceptability of both the analyses and the proposed TS changes provided to l
the NRC.
In addition, References 6 through 10 provided criteria for plant t
specific implementation of the generically approved TS changes. Our compliance with these criteria is discussed in the Safety Assessment of this Change i
l Request.
l This Change Request proposes TS changes to the actuation instrumentation supporting the RPS and ECCS, including instrumentation common to the CRBF and the isolation instrumentation common to the RPS and/or ECCS. These changes are specifically designated in the TS mark-ups of References 6 through 10 and therefore are not further discussed here. We are also proposing TS changes to instrumentation common to RPS and/or ECCS but which are not specifically designated in References 6 through 10.
These proposed changes are addressed in the analyses of References 2 through 5 but were not specifically designated in the TS mark-ups submitted as part of References 2 through 5.
These changes will provide a complete consideration of all systems / components initiated by RPS or ECCS instrumentation which are tested on a monthly schedule and are NRC approved
' i 1
1
Docket Noso 50-352 50-353 License Nos. NPF-39 NPT-85 for testing on a quarterly schedule as detailed in References 6 through 10. All changes are shown in Attachment 3.
However, only those changes not specifically designated in References 6 through 10 are described below.
1.
Trip function 6.h. "Drywell Pressure-High/ Reactor Pressure-Low " listed on TS page 3/4 3-30 is a combined trip function composed of two individual ECCS trip functions whose STIs were evaluated and found acceptableforbeingchangedfrom"M"(monthly)to"Q"(quarterly)as detailed in Reference 4.
Since Trip Function 6.h uses cosmon trip instrumentation, we propose to change the STI to quarterly. As discussed in Enclosure 1. GE Document No. OG9-1219-320 letter W. P.
Sullivan,GeneralElectric(GE)CompanytoBWROGTechnical Specification Cosmittee (TSC), dated December 22. 1989. " Clarification of Limerick 1 and 2 Proposed Technical Specification Changes Common to Reactor Protection System or ECCS Actuation Instrumentation." this change is bounded by the analysis of Reference 4, 2.
The EOC-RPT system uses trip functions common to RPS. Therefore, we propose to change the EOC-RPT system STIs and A0Ts on TS pages 3/4 3-46, 3/4 3-48, and 3/4 3-51 to conform to the TS changes made for RPS instrumentation. Enclosure 1 details the fact that the analysis of Reference 4 bounds the proposed TS changes for EOC-RPT.
3.
The RCIC system uses trip functions common to ECCS and therefore we propose changes to TS pages 3/4 3-53, 3/4 3-54, and 3/4 3-56 to be consistent with other 15 changes for ECCS instrumentation. Due to an oversight, changes to these TS were not specifically included in the TS mark-ups provided to the NRC in Reference 5. although they are addressed in the Reference 5 analysis. Enclosure 2. GE document No.
0G9-749-320, letter from W. P. Sullivan, GE. to BWROG Technical Specification Committee, dated August 7. 1989. " Clarification of Technical Specification Changes Given in ECCS Actuation Instrumentation Analysis." provided mark-ups for these changes to the RCIC system TS to the BWROG TSC. Enclosure 5. GE Document No. OG90-319-320 letter from W. P. Sullivan, GE to U.S. NRC. dated March 22. 1990. " Clarification of Technical Specification Changes Given in ECCS Actuation Instrumentation Analysis " provided justification and TS mark-ups to the NRC for these changes to the RCIC TS.
4.
The proposed TS changes to TS Section 3/4 3.3.3 on page 3/4 3-36 provide a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> A01 for ECCS instrumentation which is consistent with the analysis in Reference 5.
The proposed wording differs from the TS mark-up of Reference 5 which implies an allowance of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> before taking the action of TS Table 3.3.3-1.
Enclosures 2 and 5 provide a clarification on the intent of the Reference 5 TS mark-up and also provide revised wording. We have proposed a TS change consistent with Enclosures 2 and 5.
5.
An administrative change to a TS Index page is also proposed. We propose a change to index page "xix" to reflect additions to the TS Bases which reference the appropriate L1R(s) and accompanying SER(s).
Each of the TS Instrumentation Bases pages changes are proposed either.
i Docket Nos. 50-352 50-353 License Nos. NPF-39 NPF-85 to make additions, as just described, or to accomodate carryover from apreviouspage(asaresultoftheadditions).
Safety Assessment The effect on safety of the proposed extensions to the STIs and A0Ts of the actuation instrumentation supporting the RPS, and the ECCS including the instrumentation comon to the CRBF, and the isolation instrumentation comon to the RPS and/or ECCS has been addressed in References 2 through 5..Further, the NRC has detailed their acccptance of the analyses and conclusions of References 2 through 5 in SERs (References 6 through 10). The SERs conclude that implementation of the TS changes proposed in References 2 through 5 would-provide an overall enhancement to plant safety and that the proposed changes to TS are acceptable subject to the Licensee documenting 1) plant-specific applicability 2) that instrument drift is bounded by the generic analysis assumptions, and 3) confirmation that differences between plant-specific and generic RPSs were included in the plant-specific analysis. These acceptance 4
conditions are addressed below.
i 1.
A plant-specific review of the LTRs' (References 2 through 5) applicability to LGS has been conducted.- For the RPS, the review compared the LGS RPS configuration and surveillance test procedure with the generic RPS evaluated in the LTR.
The differences between the two were identified and the i
reliability effect of the differences was assessed. The differences and-their effect are documented in a separate GE report Enclosure 3 document No MDE-93-0485-1, " Technical Specification Improvement Analysis for the Reactor Protection System for Limerick Generating Station Units 1 and 2."
dated October 1987. The report identifies seven differences which were dispositioned by either an engineering assessment or additional analyses.
The report concluded that these differences would not significantly affect l
j the improvement in plant safety which would be obtained through the TS l
changes evaluated in the generic analysis and that the generic analysis is applicable to LGS Units 1 and 2.
For ECCS, a similar review was conducted. The results are documented in a separate GE report, Enclosure 4, document No. RE-019. " Technical Specification Improvement Analysis for Emergency Core Cooling System L
Actuation Instrumentation for Limerick Generating Station Units 1 and 2."
dated December 1986. The report concludes that the ECCS configuration for L
LGS is similar to the generic analysis with only one significant difference.
The difference was modeled by envelope case 4A of Reference 5. Part 1, which shows that the proposed changes to ECCS instrumentation would meet the 4%
acceptance criterion of Reference 5. Part 2.
In addition there have been no modifications to the RPS or ECCS since issuance of Enclosures 3 and 4 which would invalidate the conclusions of these reports. Therefore, the generic analysis is applicable to LGS.
2.
In 1988, the NRC issued additional guidance regarding instrument drift l
(Reference 11). This letter states that " licensees need only confirm that i
the setpoint drift which could be expected under the extended STIs has been i
~ studied and.either (1) has been.shown to remain.within the existing allowance in the RPS (for BWRs)... instrument setpoint calculation or (2) :
i Docket N3s.
50-352 50-353 License Nos. NPF-39 NPF-85' i
that the allowance and setpoint have been adjusted to account for the additional expected drift." Present setpoint calculations for LGS are based on an eighteen (18) month calibration interval. Therefore, drift occurring i
during a three month STI falls within the existing drift allowance. To further verify this, instrument drift data was examined over three (3) consecutive monthly test intervals. Enclosure 6. " Limerick Generating-Station, Unit 1. Instrument Drif t Data for RPS, and ECCS, Including Comunon Instrumentation," provides the as-found drift data on a ten percent (10%)
e sample of LGS Unit 1 RPS and ECCS instrumentation (this includes comunon instruments). Sincr: identical instrumentation is used on LGS Unit 2, the Unit I sample is cdasidered representative. The data provides actual i
verification that '.he drift occurring over 3 cor.secutive test intervals (one calendar quarter) is within K Cuptable limits.
3.
We have reviewed the GE piant-specific report for LGS and have verified that the differences between the LGS and generic RPS were included in the plant-specific analysis. 1herefore, the generic analysis in Reference 2 is applicable to LGS.
As discussed above we have conformed.to the guidance provided in References 6 throagh 10 in the three areas to be addressed by Licensees to ensure the acceptability of proposed TS chsnges. As noted previously, several changes are also proposed which are not specifically referenced in the NRC SERs (References 6 through 10). The following discussion-addresses the acceptability
]
of these proposed changes.
1.
Reactor low water level and high drywell pressure were identified in Reference 4 as the primary and secondary isolation trip functions comunon to either the RPS or ECCS actuation trip functions.
In the LGS Units 1 and 2 TS, the combined high drywell pressure and' low reactor pressure trip function for primary containment isolation is-also comanon to the ECCS t
actuation trip function. The STI for this combined trip function was not l
changed in the sample modified isolation actuation TS in Table.4.3.2.1.1, Item 6.h. of the NRC SER (Reference 8). Although this change was not
{
explicitly identified in the Reference 4 analysis as a comunon
[-
instrumentation trip function, the change is still bounded by the NRC approved Reference 4 analysis.
In the Reference 4 analysis, the effect of changing a single isolation trip function STI (either reactor low water i
level or high drywell pressure) was evaluated to have an acceptably low effect on the isolation actuation failure frequency. Since the combined l
high drywell pressure and low reactor pressure trip function-is backed up by the low reactor water level trip function, the effect of changing the STI for this combined trip function is also acceptably low.
For this rea';on, changing the STI from one month to three months for the combined high drywell and low reactor pressure trip function is bounded by the NRC SER.
2.
The E0C-RPT is initiated by signals comunon to the RPS.
These signals (turbine stop valve closure and turbine control valve low hydraulic pressure) were not identified as comunon trip functions in the RPS TS 4
improvementanalysis(Reference 2). Although STI changes to the comenon E0C-RPT-tripefunctions were not explicitly identified.in the Reference 2 analysis, the changes can be considered bounded by this analysis. The basis
-S-
. ~
Docket N:s.
50-352 50-353 License Nos. NPF-39 NPF-85 L
for this conclusion is similar to the basis' established in' Reference 3 for the control rod block instrumentation common to the RPS. Failure of the EOC-RPT trip function could lead to exceeding the Minimus Critical Power Ratio (MCPR) similar to the consequences of an unmitigated rod withdrawal i
error. The slight increase in risk of a MCPR violation due to extending E0C-RPT STIs is offset by the benefits associated with the similarly approved STIs for the RPS. This is the same reasoning that was used in Reference 3 and approved by the NRC in Reference 7.
3.
Analysis of the effects of extending A0Ts and STIs for the RCIC system l
instrumentation was completed and found acceptable as detailed in Reference b llowever, due to an oversight, proposed changes to the TS were not l
specifically requested in Reference 5 and therefore not specifically addressed in Reference 9.
This oversight does not affect the acceptability of these proposed changes, since the methods and results of Reference 5 were 1
j found acceptable as documented in Reference 9.-
Recognizing that mark-ups to the RCIC system instrumentation TS had not been.
previously included in Reference 5, GE provided TS mark-ups for all GE BWR product lines, incorporating the extended STIs:and A0Ts for RCIC system._
instrumentation. The mark-ups were provided to_the BWROG TSC members under cover letter dated August 7, 1989 (Enclosure 2), and discussed and described in Enclosure 5.
4.
Also discussed in Enclosure 2 and Enclosure 5 is a clarification of the applicability of the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> TS A0T for ECCS Actuation Instrumentation. The 4
change provides a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> A0T in those TS Action Statements which are applicable to specific instrumentation. The intent of.the change is to preclude the allowance of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> before taking the Action specified in TS' Table 3.3.3.1.
Action "b" of TS paragraph 3/4 3.3, as written in Reference 5, implies a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> A0T before taking any action in TS Table 3.3.3-1.
The change we have proposed accurately reflects the intent of the Reference 5 analysis. This change therefore is necessary to obtain the overall enhancement to safety that is possible by extending STIs and A0Ts.
5.
The proposed administrative change to Index page "xix" is necessary to accurately reflect the location of various Sections in the TS Bases. This change has no impact on safety.
References 6 through 10 provided TS changes based on review of the LTRs (References 2 through 5). We have proposed TS changes consistent with those previously approved and specifically designated in References 6 through 10.
In addition, several changes are proposed which are not explicitly referenced in i
the NRC SERs, but are covered by the analyses detailed in References 2 through 5 and Enclosures 3 and 4, and are acceptable as discussed above.
l l
In sussiary, the NRC criteria for demonstrating the applicability and acceptability of all proposed changes has been shown to be met, as detailed l
above. We therefore conclude that the changes proposed will minimize l
unnecessary testing and relax excessively restrictive A0Ts, and will provide an
.overall enhancement to plant safety. !
I
4 i
Docket Nns.
50-352 1
50-353 License Nos. NPF-39 NPF-85 Information Supporting a finding of l
No Significant Hazards Consideration We have concluded that the proposed changes to the LGS TS, which extend STIs and A0Ts for the RPS and ECCS instrumentation, and instrumentation common to RPS and/or ECCS, do not constitute a Significant Hazards Consideration.
In i
support of this determination, an evaluation of each of the three standards set l
forth in 10 CFR 50.92 is provided below.
1)
The proposed changes do not involve a significant increase in the probability or consequences of an accident previously evaluated.
The proposed TS changes increase the STIs and A0Ts for actuation 4
instrumentation supporting RPS, and ECCS, including instrumentation common to the CRBF, RCIC system EOC-RPT, and isolation functions.
In addition, an Index page revision is necessary to reflect the addition of LTR and SER references in the TS Bases, which caused the location of several TS Bases sections to change. There are no changes in any of the affected systems themselves. Since there are no'such changes, there can be no change in the probability of occurrence of an accident or the consequences of an accident or the consequences of malfunction j
of equipment. Regarding the probability of malfunction of equipment,-
LTRs prepared by GE showed that for the RPS there is a reduction in scram frequency, but that in the ECCS case, there is a small increase i
in the unavailability of the water injection function. This increase l
in unavailability was judged acceptable by GE. The NRC,.in its review of the LTRs (References 2 through 5), concurred with this conclusion.
The changes proposed are consistent with these SERs (References 6 through 10) with several additions. These additional changes are.
i bounded by the analyses of References 2 through 5 as detailed in this-j Change Request and in Enclosures 1, 2, and 5.
Therefore the proposed changes do not involve a significant increase in the probability or i
consequences of an accident previously evaluated.
i 2)
The proposed changes do not create the possibility of a new or different kind of accident from any accident previously evaluated.
The proposed TS changes do not create the possibility for an accident or malfunction of a different type than any evaluated previously in the Final Safety Analysis Report (FSAR). The proposed changes increase the STIs and A0Ts for the RPS and ECCS instrumentation, and common l
instrumentation, and revise an Index page to reflect the addition of references to the TS Bases. There are no changes in the RPS, ECCS or conson systems themselves. Since there are no such changes, there is
(
no possibility for an accident or malfunction of a different type than-any evaluated previously.
l' 3)
The proposed changes do not involve a significant reduction in a margin of safety.
The. proposed TS changes do not. reduce the margin of safety as defined in the basis for any TS. The proposed TS changes do not change any I
e.-da-aiJ4-h-+M,.p, m.-me,-
as
_sa'.--e
,-e-m n-s Fa--ae
- m-
_--A--.#
u-..
.-w l
Docket Nas. 50-352-50-353 1
License Nos. NPF-39 NPF-86 1
setpoints in the RPS or ECCS instrumentation, or common systems, or their levels of redundancy.- Setpoints are based upon the drift.
occurring during the 18 month calibration interval.. The proposed i
changes extend STIs and A0Ts. The Bases in the TS either do not
]
discuss STIs, or. state "... one channel may be inoperable for brief intervals to conduct required surveillance." The proposed TS changes discussed in References 2 through 5, as well as the additional changes discussed in this Change Request and Enclosures 1, 2, and 5 are bounded i
by the analyses in References 2 through 5.
Theseanalyses(References 2 through 5) prepared by GE and reviewed and approved by the NRC examined the effects of extending STIs and A0Ts and found.that the proposed changes'would not involve a significant reduction in a margin
]
of safety.
-l Information Supporting an Environment Assessment An environmental assessment is not required for the changes proposed by this Change Request because the requested changes conform to the criteria for
" actions eligible for categorical exclusion," as specified in 10 CFR-51.22(c)(9). The requested changes will have no impact on the environment. The proposed changes do not-involve a significant hazards consideration as. discussed in the preceding section. The proposed changes do not involve-a significant change in the types or significant increase in the amounts of any effluents that may be released offsite.
In addition, the proposed changes do not involve a significant increase in individual or cumulative occupational radiation exposure.
Conclusion The Plant Operations Review Committee and the Nuclear Review Board have t
reviewed these proposed changes to the TS'and determined that they do not involve an unrev!ewed Safety Question and will not endanger the health and safety of the public.
I t
I t
m.
=
~. - -
l REFERENCES 1.
S. Wisweswaran, et-a1., "BWR Owners' Group Response to NRC Generic Letter 83-28. Item 4.5.3," General Electric Company, NEDC-30844, January 1985.
2.
W. P. Sullivan, et al., " Technical Specification Improvement Analyses for BWR Reactor Protection System," General Electric Company, NEDC-30851P, May 1985.,
3.
S. Wisweswaran, et al., " Technical Specification Improvement Analysis for BWR Control Rod Block Instrumentation," General Electric Company, NEDC-30851P, Supplement 1. June 1986.
4.
L. G. Frederick, et al., " Technical Specification Improvement Analysis for-BWR Isolation Instrumentation Common to RPS and ECCS Instrumentation,"
General Electric Company, NEDC-30851P, Supplement 2. July 1986.
5.
D. B. Atcheson, et al., "BWR Owners' Group Technical Specification Improvement Methodology (with Demonstration for BWR ECCS Actuation Instrumentation," Parts 1 and 2. General Electric Company, NEDC-30936P, November 1985.
6.
Safety Evaluation by the Office of Nuclear Reactor Regulation
" Review of i
BWR Owners Group Reports NEDC-30844 and NEDC-30851P on Justification for an Extension of On-Line Test Intervals and Allowable Out-of-Service Time for BWR Reactor Protection Systems," July 15, 1987.
7.
Safety Evaluation by the Office of Nuclear Reactor Regulation
" Review of BWR Owners Group Report NEDC-30851P, Supplement l'on Justification for Extension of On-Line Test Intervals for BWR Control Rod Block-Instrumentation," September 22, 1988.
8.
Safety Evaluation by the Office of Nuclear Reactor Regulation
" Review of BWR Owners Group Report NEDC-30851P, Supplement 2 on Justification for Extension of Surveillance Test Intervals and Allowed Outage Times-for BWR Isolation Instrumentation Common to RPS and ECCS Instrumentation " January t
l 6, 1989.
9.
Safety Evaluation by the Office of Nuclear Reactor Regulation
" Review of BWR Owners Group Report hEDC-30936P on Justification for Extending On-Line Test Intervals and Allowable Out-of-Service Times for BWR Emergency Core l
Cooling System Instrumentation," December 9, 1988.
a L
- 10. Safety Evaluation by the Office of Nuclear Reactor Regulation
" Review of BWR Owners Group Report NEDC-30936P (Part 2) on Justification for Extending On-Line Test Intervals and Allowable Out-of-Service Times for-BWR Emergency Core Cooling System Instrumentation," December 9, 1988.
- 11. C. E. Rossi, NRC, to R. F. Janacek, BWROG, " Staff Guidance for Licensee Determination that'the Drift Characteristics for Instrumentation Used in RPS Channels are Bounded by NEDC-30851P Assumptions when the Functional Test Interval is Extended from Monthly to Quarterly," April 27, 1988.
(
l l
l l
l
...