ML20206H924
| ML20206H924 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 11/11/1988 |
| From: | Larson C NORTHERN STATES POWER CO. |
| To: | Harrison J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| IEB-79-14, NUDOCS 8811230437 | |
| Download: ML20206H924 (2) | |
Text
, 76 Northem States Power Company 414 Nicollet Mari M.nneapohs, Minnesota 55401 1927 Telephone (612) 330-5500 November 11, 1988 P-J J Harrison, Chief Engineering Eranch U S Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, 11,60137 PRAIRIE IS1AND NUCLEAR GENERATING PLANT Docket Nos. 50-282 License Nos. DPR-42 50-306 DPR-60 Response to Inspec 'on Reports 50-282/88017(DRS) and sJ-306/88017(DRS)
In response to your letter of October 12, 1988, whica transmitted Inspec-tion Reports No. 282/88017 and 306/88017, the following information is offered.
Violation 10 0FR 50.59 requires a written safety evaluation which provides the bases for the determination that a change does not involve an unreviewed safety question.
Contrary to the above, the bases for Safety Evaluation Report "Justifica-tion for Continued Operation Due to Increased Valve Weights of Small Bore Copes Vulcan Control Valves", Report No. 000259-1, Revision 1, transmitted on May 6, 1968, were invalid in that Class I design fatigue curves were used as acceptance criteria for operating and design basis seismic stresses. Additionally, the basis for concluding that if the lines were to rupture, the high head safety injec*. ion system would still meet the design requirements was never delineated or established in the safety evaluation (282/88017-01; 306/88017-01)
This is a Severity Level IV violation (Supplement 1)
Response
During the implementation of a prograin to reassess the origirni IE Bulletin 79-14 evaluation it was discovered that the vendor information regarding valve weight and centor of gravity for certain small bore Copes-Vulcan valves used in the original piping design contained discrepancies.
As a result of those discrepancies, some piping subsystws required re-analysis to determine if seismic stresses would meet code allowables.
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Northem States Power Company J J Harrison November 11,-1988 Page 2 A safety evaluation (SE #239, Report No. 000259-1, Rev. 1) was prepared to l
justify continued operation until the analyses could be completed and any required modifications could be implemented.
Corrective Action Taken and Results Achieved The pipe supports in the piping system that was the subject of the refer-enced Safety Evaluation (SE #239, Report No. 000259-1, Rev. 1) have been modified and all stresses are now within code allowables.
Generic criteria to be utilized for the justification of continued opera-tion when major discrepancies in "as-built" safety related piping are en-countered were submitted to the Commission by NSP letter dated September 26, 1988. This criteria outlines specific technical limits for such situa-i tions and requires a system operability review per the plant Technical
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Specifications if the technical criteria cannot be met.
The generic cri-teria were reviewed by the NRC Sttff and their acceptance of the generic criteria is documented in the subject Inspection Report.
All piping systems re analyzed as a result of die Copes Vulcan valve prob-r lem have been found to meet code allowables, satisfy the NRC approved ge-neric justification for continued operation criteria, or have been eval-uated and found to meet Technical Specification operability requirements.
l Corrective Action Taken to Avoid Further Violations i
The NRC approved generic criteria will be utilized for the justification of f
continued operation for any major discrepancies in as built safety related piping found in the futuro.
t Date When Full Compliance Vill Be Achieved
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Full compliance has been achieved.
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Please contact us if you have any questions related to our response to i
these violations.
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A 4 C E Larson Vice President Nuclear Generation l
c: Regional Administrator III, NRC NRR Project Manager, NRC i
Senior Resident Inspector, NRC G Charnoff i
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