ML13317B076
| ML13317B076 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 04/02/1982 |
| From: | Crutchfield D Office of Nuclear Reactor Regulation |
| To: | Dietch R SOUTHERN CALIFORNIA EDISON CO. |
| References | |
| RTR-REGGD-01.121, RTR-REGGD-1.121 LSO5-82-04-006, LSO5-82-4-6, NUDOCS 8204090293 | |
| Download: ML13317B076 (3) | |
Text
April 2, 1982 Docket No. 50-206 LS05-82-04-006 Mr. R. Dietch Vice President Nuclear Engineering and Operations Southern California-Edison Company 2244 Walnut Grovd Avenue Post Office Box 800 Rosemead, California 91770
Dear Mr# Dietch:
SUBJECT:
STEAM GENERATOR PUUGGING LIMIT SAN ONOFRE NUCLEAR GENERATING STATION UNIT NO. 1 On June 8, 1981,.the Commission issued License Amendment No. 55 to Provisional Operating License No. OPR-13 for the San Onofre Nuclear Generating Station (SONGS) Unit No. 1. The amendment authorized changes to the technical specifications which were required to allow SONGS Unit No. 1 to resume power operation for Cycle 8 following extensive repair to the steam generator tubes and, among other pro visions, provided clarification of the preventative plugging limits.
Our letter stated that we and your representatives mutually agreed to a change to your May 5, 1981 application to include a more con servative plugging limit of 40% for sleeve degradation until our review of your proposed limit of 54% degradation is completed.
In order to meet the provisions of Regulatory Guide,1.121, it is necessary to demonstrate that the degraded tubes have adequate wall thickness to preclude exceeding the yteld stress during normal operation and adequate safety margins exist during postulated accident conditions. You have satisfied these two criteria with your proposed plugging limit of 54%* However, a third criterion specified in Regulatory Guide 1.121 requires that a margin of 3.0 t5 u against burst be maintained during normal operation. With the pro posed plugging limit of 54%, this margin to burst under normal operating pressure would be 2.4 and, therefore, tie find that it is unacceptable. Westinghouse has previously taken exeeption to this position, but the NRC staff continues to believe that the maintenance 8204090293 820402 PDR ADOCK 05000206 P
PDR OFFICE SURNAME DATE I......-.
NRC FORM 318 (10-80) NRCM 0240 OFFICIAL RECORD COPY USGPO: 1981-335-960
Mr. R. Dietch
- 2 April 2, 1982 of this margin of three during normal operation is necessary for degraded as well as sleeved tubes* This staff position is con sistent with acceptance criteria provided in ASME Code Section XI Subsection IWB.3521.1 which requires that the depth of an allow able O.D.indication not exceed 40% of the tube wall thickness.
With this plugging limit,.a margin of three against burst would be maintained during normal operation. Accordingly, we conclude that-your proposed plugging limit of 54% tube degradation for sleeved tubes is not acceptablegand that this limit should remain at 40%.
Please contact Mr. W. Paulson, NRC Project Manager for San Onofre Unit No. 1 if you have any questions regarding this matter.
Sincerely, Dennis M. Crutchfield, Chief Operating Reactors Branch #5 Diviiion of Licensing cc: See next page DISTRIBUTION Docket NRC PDR Local PDR ORB Reading NSIC DCrutchfield HSmith WPaulson OELD OI&E ACRS (10)
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NRC FORM 318 (10-80) NRCM 0240 OFFICIAL RECORD CO PY USGPO: 1981-335-960
Mr. R. Dietch 3
April 2, 1982 cc Charles R. Kocher, Assistant General Counsel James Beoletto, Esquire Southern California Edison Company Post Office Box 800 Rosemead, California 91770 David.R. Pigott Orrick, Herrington & Sutcliffe 600 Montgomery Street San Francisco, California 9411 Harry B. Stoehr San Diego Gas & Electric Company P. 0. Box 1831 San Diego, California 92112 Resident Inspector/San Onofre NPS c/o U. S. NRC P. 0. Box 4329 San Clemente, California 92672 Mayor City of San Clemente San Clemente, California 92672 Chairman Board of Supervisors County of San Diego San Diego, California 92101 California Department of Health ATTN:
Chief, Environmental Radiation Control Unit Radiological Health Section 714 P Street, Room 498 Sacramento, California 95814 U. S. Environmental Protection Agency Region IX Office ATTN:
Regional Radiation Representative 215 Freemont Street San Francisco, California 94111 Robert H. Engelken, Regional Administrator Nuclear Regulatory Commission, Region V 1450 Maria Lane Walnut Creek, California 94596