ML20005D620
| ML20005D620 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 10/31/1989 |
| From: | Creel G BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| RTR-NUREG-1335 GL-88-20, NUDOCS 8911070343 | |
| Download: ML20005D620 (5) | |
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. CHARLES CENTER P. O. BOX 1475' BALTIMORE, MARYLAND 21203 Gcostot C. CattL October 31, 1989 vice eas.ioca, wuctc.. cacao, noo........
.q U. S. Nuclear Regulatory Commission -
Washington, DC 20555 ATTENTION:
Document Control Desk f'
SUBJECT:
Calvert Cliffs Nuclear Power Plant.
Unit Nos.1 & 2; Docket Nos. 50-317 & 50-318 Proposed Program For Completing The Individual Plant Examination -
Initial Resnonne to Generic Letter No. gg-20
REFERENCES:
(a) U. S. Nuclear Regulatory Commission, " Initiation-of the Individual
'l Plant Examination for Severe Accidest Vulnerabilities," Federal Regis.ter. Vol. 54, No.169, September-1, 1989, 36402 (b) Initiation of the Individual Plant Examination - for Severe Accident Generic Letter No. 88-20, 10 CFR 50.54(f)
Vulnerabilities Supplement No.1, August 29, 1989 Li (c) Individual Plant Examination for Severe Accident Vulnerabilities -
'i 10 CFR 50.54(f) (Generic Letter No. 88-20), November 23, 1988
' Gentlemen:
i What follows are our plans for completing the Individual Plant Examination (IPE) that b
was first mentioned in NRC's Policy Statement on Severe Accidents Regarding Future t
~ :ft Designs and Existing Plants, issued on August 8, 1985 (50 FR 32138). The references l
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cited : above identify the information that is required in this initial response. They also provide guidance.for reporting the results of our IPE. We used those references in preparing this response and in developing our plan for completing our IPE.
<.4 In brief, we plan to perform a Level 1 Probabilistic Risk Assessment (PRA) for Unit 1.
That Level 1 PRA will generally follow techniques outlined in NUREG/CR-2300 We q
plan to perform a containment performance analysis for Unit I that follows the general guidance given in Appendix 1 of Generic Letter 88-20. We plan to screen Unit 2 for i
differences between it and Unit
- 1. Where appropriate, we will incorporate differences 1
into models and evaluate changes in results.
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L We began our IPE for Unit I in January 1989. The IPE for Unit I and the screening and evaluation of Unit 2 is scheduled to be completed in mid-1992. We plan to submit a l
summary report for both Unit I and Unit 2, in accordance with NUREG-1335, in the third l j quarter 1992.
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. Document Co2 trol Clerk October 31, 1989 Page 2 -
.s Attachment (1) to this letter provides more detailed information on our plans and provides some background information regarding past risk evaluations of Calvert Cliffs.
This information provides you with additional insight into how we arrived t.t our plans and schedule.
We are in the first year of what we project to be a 3-l/2 year effort. We will notify you if our plans change from what we have described in this letter and attachment. In addition, we would like to open a dialogue with the Staff that will review our summary report. as soon as it is possible. This will help both of us establish common expectations for those aspects of the IPE that are more judgemental and less prescriptive before we proceed too far.
We hope this provides you with all the information that you need at this point in the process. If you need additional information or if you have any questions, do not hesitate to contact us.
Very truly yours STATE OF MARYLAND g
TO WIT :
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,19[ before me, the I hereby certify that on the subscriber, a ptary Public of the State of Maryland in and for E
t& /M7/USYruAF8/ personally eppeared George C. Creel, being duly sworn, and stat that he is' Vice President of the Baltimore Gas and Electric Company, a corporation of the State of Maryland; that he provides the-foregoing response for the purposes therein forth; that. the statements made are true and correct to the best of his knowledge, set information, and ~ belief; and that he was authorized to provide the response on behalf of said Corporation.
dd 28 M WTI' NESS my lland and Notarial Seal:
Notary Pub [c I
My Commission Expires:My commission 9p; M I.1990 Y
Date GCC/ WPM /bjd Attachment
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Document Control Clerk October 31,1989 S-Page 3 cc:
D. A. Brune, Esquire J. E. Silberg, Esquire R. A.Capra, NRC S. A.McNeil NRC W. T. Russell, NRC J. E. Beall, NRC T. Masette, DNR D. Modeen. NUMARC
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f ATTACHMENT f11 I
i BACKGROUND Calvert Cliffs has been the subject of several risk evaluations. These evaluations have been performed with various levels of BG&E staff involvement.
We participated in Phase 11 of the Interim Reliability Evaluation Program (IREP). A study of Unit I, initiated in September 1980, was performed by a team comprised of individuals from BGAE, the U. S. Nuclear Regulatory Commission, and its contractors.
The two team members from BG&E provided information on plant design and operation to help model plant systems and operator responses. The final report was issued in March 1984. (1)
BG&E also participated in the Industry Degraded Core Rulemakins (IDCOR) Program.
Cidvert Cliffs was one of four plants for which a limited-scope snalysis was performed.
Several important aspects of the IDCOR methodology were not done or were performed in a limited fashion. These include:
f Plant walkdowns were not performed.
Only limited plant data was developed, system notebooks were not developed, and most system information was previously developed in other studies.
Common location evaluations of internal flooding and fires were not performed.
A report documenting the IDCOR evaluation was issued in June 1987. (2)
A third analysis was performed for the Reactor Safety Study Methodology Applications Program (RSSMAP). This analysis did not involve BG&E staff, it was conducted for Unit 2 primarily with information available in the Final Safety Analysis Report, Technical l
Specifications and selected plant procedures. A report was is. sued in May 1982. (3)
While these previous evaluations provide valuable insights with tegard to plant risk, a significant amount of rework and many enhancements would be required to meet the l
guidance of Generic Letter 88-20. Therefore, IREP, IDCOR, and RSSMAP will be used l
for reference only.
METHOD AND APPROACH We plan to:
Develop a Level 1 PRA for Unit I which generally follows techniques outlined in NUREG/CR-2300. This analysis will address unit-to-unit dependencies.
Develop a containment performance analysis for Unit I that follows the general guidance given in Appendix 1 of Generic Letter 88-20.
Screen Unit 2 for differences in design, incorporate, where appropriate, these differences into models and evaluate the changes in results.
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O c) l ATTACHMENT f1) l i
Use BGAE engineers for analysis and the technical review. These BG&E engineers t
will be familiar with the details of the design, controls, procedures, and system configurations.
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Conduct a formal, independent, in-house review to ensure the accuracy of the documentation packages and IPE process and to provide confidence in its results and conclusions. Reviews will be performed on an analysis-by analysis bases (e.g.,
system analysis, initiating event analysis) by individuals involved with the IPE, but not previously involved in the analysis being reviewed.
i Perform physical plant walkdowns only when required information is not available through design documentation.
Initial walk-throught for plant familiarization are considered unnecessary because of the extensive participation by BGAE engineers familiar with the plant.
REFERENCES (1)
NUREG/CR-3511, March 1984, ' Interim Reliability Evaluation Program: Analysis of
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the Calvert Cliffs Unit i Nuclear Power Plant *
(2)
IDCOR Technical Report 86.2CC, June 1987, ' Verification of IPE for Calvert Cliffs" (3)
NUREG/CR-1659/3 of 4, May 1982, ' Reactor Safety Study Methodology Applications Program: Calvert Cliffs w2 PWR Power Plant
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