ML20033G468
| ML20033G468 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 03/19/1990 |
| From: | Tucker H DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.D.1, TASK-TM TAC-44593, TAC-54601, NUDOCS 9004100036 | |
| Download: ML20033G468 (2) | |
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l'O Box 33198 Var l'rrsident Charlotte, NC 28 42 Nuclear Imluction (104).173 4531 DUKE POWER March 19, 1990 q
U. S. Nuclear Regulatory Commission ATTN Document Control Desk Washington, D.C.
20555
Subject:
McGuire Nuclear Station Docket Nos. 50-369 and 50-370 NUREG-0737 Item II.D 1, Performance Testing of Relief and Safety Valves NRC Review / Technical Evaluation Report -
Responso Supplement Schedule (TACS 44593 and 54601)
Gentlement My 1ctter of September 18, 1989 concerning deficiencies noted in the NRC's l
Technical Evaluation Report (TER) of tho McGuire Nuclear Station response to NUREG-0737 Item II.D.1, " Performance Testing of Relief and Safety Valves",
discussed an error that had been identified in the existing thermal hydraulic analysis (SLUGGER computer program) which invalidated the existing structural calculation results for the piping downstream of the pressurizer safety valves. Duke had reviewed the impact of the load changes due to this error on the structural analysis for the system and found that the system remained operable but was not in full compliance with the ASME Code, and Duke was reviewing reanalysis / field modification alternatives to bring the system within ASME Code compliance.
It was noted that as a result of the reanalysis / field modification review, Duke had entered into a contract with the B&W Corporation to reperform the thermal hydraulic analysis using the RELAP 5 computer code on the piping downstream of the pressurizer code safety valves. The letter also stated that several alternatives would be modeled as part of this reanalysis.
Information regarding this ASME Code compliance was to be included in a response addressing the results of combining seismic with the original analysis results (i.e. the Items 7 and 8b TER requested additional information).
The work by B&W was completed on March 5, 1990 and is currently under review. Based on a preliminary review, Duke believes that the most prudent course of action to resolve this issue will be to pursue a system modification to change the seal configuration for the code safety valves by installing a continuous drain for the existing loop piping and either modify existing valves or purchase new valves that will seal with a steam medium.
Duke has begun the process to generate a nuclear station modification request to perform the work described.
Duke is also reviewing different alternatives of a new valve purchase versus existing valve modification.
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- March 19,1990 An assessment of the result of this review and a schedule for performing and implementing this work in accordance with ASME requirements will be submitted by August 1, 1990.
This response, reflecting the completion of the thermal hydraulic and structural reanalysis, will address the Items 7 and 8b additional information requests and include the information regarding ASME code compliance.
Should there be any questions concerning this response / schedule or if further information is desired regarding the current status of the resolution of this issue, contact Bruce Nardoci at (704) 373-7432.
Very truly yours, i
I A)y llal B. Tucker PBN196/lcs xc Mr. S. D. Ebneter U. S. Nuclear Regulatory Commission Region 11 101 Marietta St., NW., Suite 2900 Atlanta, Georgia 30323 Mr. D. S. Ilood, Project Manager Division of Licensing Office of Nuclear Regulatory Commission Washington, D.C.
20555 Mr. P. K. VanDoorn NRC Resident Inspector McGuire Nuclear Station i
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