ML20118A700
| ML20118A700 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 09/18/1992 |
| From: | Creel G BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-88-20, TAC-M83603, TAC-M83604, NUDOCS 9209250003 | |
| Download: ML20118A700 (4) | |
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B A LTIMORE GAS AND ELECTRIC i
1650 CALVERT CLIFFS PA9KWAY e LUSBY, MARYLAND 20657-4702 OtoHot C Cntrt m won v,u enat em (4101200 4090 September 18,1992 U. S. Nuclear Regulatory Commission Washington, DC 20555 ATFENTION:
Document Control Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit Nos.1 & 2: Docket Nos. 50 317 & 50-318 Reassessment of Schedule for Generic Letter 88-20, Jupplement 4, Individual Plant Examination of External Events (IPEEE) for Severe Accident Vulnerabilities (TAC Nos. M8360AMR3604)
REFERENCES:
(a)
Generic Letter 88-20, Supplement 4, dated June 28,1991, Individual Plant Examination of External Events (IPEEE) for Severe Accident Vulnerabilities - 10 CFR 50.54(f)
(b)
Letter from Mr. D. G. Mcdonald, Jr. (NRC) to Mr. G. C. Creel (BG&E), dated June 30, 1992, Review of Response to Gencric Letter 88-20, Supplement 4; Individual Plant Examination of External Events (IPEEE) for Severe Accident Vulnerabilities 10 CFR 50.54(f)
Gentlemen:
In accordance with Generic Letter 98-20, Supplement 4 (Reference a), we provided a description of our proposed program and schedule for completing the Individual Plant Examination of External Events (IPEEE). We identified June 1996 as the expected submittai late for vie program results. In Reference (b), the NRC requested that Baltimore Gas and Electric Company 'BG&E) reassess our IPEEE program with the objective of moving the submittal date up to June 1995.
We have performed this reassessment ami have determined that your request c n ot be accommodated without challenging the integrity of the IPEEE program and the quality of the results.
The reasons supporting our determination are as follows:
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The IPEEE projett schedule is sequerurd with that of th-IPE resulting in the IPE Project i esources being unavailable until the end of thefirst quarter ofI993.
Calvert Cliffs' IPli Project is still in progress and has a submittal date of May 1991 This project is being developed by llG&E engineers with minimal contractor support. 'the use of IlG&li engineers meets the spirit of Generic lxtter RS-20. It helps to develop a continuirg eppreciation of severe accident behavior by having utility engineers involved in the analysis, as well as the technical review. 'lhe staffing of the IPE Project increased from two in January 1989 to the current level of six. 'lhis staff is completely dedicated to the development of the plant's examination for internal events. We intend to utilize the same staff to support the plant's examination of external events. Such an approach will ensure the analysis between internal and external events is coordinated.
2.
Using in-house sta)f to maximi:e llG& E's knowledge gainedfrom the examination would limit the total available resources.
Iloth Generic lxtter 88 20 and Generi; Letter K8-20, Supplement 4 encourage using the licensee's staff in all aspects of the examination, llaltimore Gas and Electric Company plans to maximiec the use of its internal staff. We have also found that this involvement is necessary to ensure a thorough and quality product. Additionally, it will better utilize the significant plant knowledge gained by the IPli team and will make efficient use of our litnited plant resources. The IPEEE will require not only participation of the reliability engineering staff, but also the support of operations, fire protection and scismic engineering personnel.
The IPEEE schedule considers the coordination and project impact on these various resources.
1 Coordinating the IPEEE with the various fire protection activities cruures the appropriate expertise is applied to Ihe project.
Various fire protection activities are underway at Calvert Cliffs. These activities willlimit the availability of key fire protection personnel. The proposed schedule considers the availability of these resources.
4.
Reserving the resources necessary to maintain and apply the IPE to the operation and maintenamr of Calvert Ch][s, reduces the tot.d avai!able reliability engineering resources.
Generic Letter R420 identifies several potential benefits of having a completed probabi!istic risk assessment (PRA) including: support for licensing actions, licensing renewals, risk management, integrated safety assessment. Licensees are ako encouraged to implement accident management programs.
f r.- mldition to the applications cited in Generic Letter 88-20, considerable industry activity is underway in the areas of maintenance support as a result of the Maintenance Rule (10 CFR 50.65) and in the evaluation of shutdown risk
I Dpeument Control Desk September 18,1992 Page 3 Baltimore Gas and Elcatric Company is actively pursuing application of the Calvert Cliffs PRA. Technical improvements to the PRA, such as the addition of a front end Failure Modes and Effects Analysis for each component included in the IPE and the development of a component importance ranking are underway. In addition, we plan to maintain this PRA so that it can continue to be used by a knowledgeable in-house staff. With this in mind, some of the current IPE staff is being assigned for such support. It would be imprudent to have completed a powerfui in-house PRA tool and not be able to effectively use it because all staff resources were developing the IPEEE.
5.
Coordinating the IPEEE with Unresolved Sqfety issue (USI) A-46 requires more up-front planning and links the schedules of the two projects.
The completior of IPEEE must be carefully coordinated with the resolution of USI A-46.
'This includes having adequate time to identify IPEEE components which require seismic -
evaluation to adow inclusion of these components into the scope of the seismic equipment walkdowns. It is BG&E's intent to perform the walkdowns for both USI A-46 and IPEEE in a single effort. Tins approach is encouraged by Generic Letter 88-20, Supplement 4.
6.
Performing the evaluation on a two-unit site, including the comideration of available outages to perform the necessary walldowns, establishes clear schedule limitations.
The Calvert Cliffs units are on a 24-month refueling cycle. These refueling outages will be targeted for the seismic walkdown. An interim maintenance outage is also available, but the scope of walkdowns during these short duration outages is limited. Based on the current outage schedule, the available outages are as follows: Unit 1 - spring 1991 [ Refueling Outage (RFO) -11] and 1996 (RFO-12); Unit 2 - spring 1993 (RFO-9) and spring 1995 (RFO.10). It is not anticipated that the identification of the IPEEE seismic walkdown scope will be completed for the spring 1993 outage. Tl erefore, the completion of all seismic walkdowns i
could be as late as spring 1995. Th3 leaves just over 12 months to complete the seismic risk evaluation. The post-walkdown evaluation includes the identification of the most likely severe accident sequences that could occur at Calvert Cliffs, understanding the overall likelihood of core damage and radioactive material release, and if necessary, addressing any plant-specific seismic vulnerabilities identified.
Based on the above discussion, we will maintain our current schedule and submit the IPEEE summary report by June 30,1996.
Should you have any further questions regarding this matter, we will be pleased to discuss them with you.
Very truly yours, f'
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a Docurnent Control Desk Schternber 18,1992 Page 4 D. A. Brune,lisquire cc:
J. E. Silberg. Ilsquire R. A. Capra, NP.C D. G. Mcdonald, Jr., NRr T. T. Martin, NRC P. R. Wilson, NRC R.1. Mcb:an, DNR
.11. Walter. PSC
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