ML20059C772
| ML20059C772 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 08/29/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20059C774 | List: |
| References | |
| GL-90-05, GL-90-5, NUDOCS 9009050320 | |
| Download: ML20059C772 (2) | |
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WASHING T ON, D. C. 206b5 ENCLOSURE SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO REQUESTED TEMPORARY RELIEF FROM ASME SECTION XI REQUIREMENTS PUBLIC SERVICE ELECTRIC & GAS COMPANY PHILADELPHIA ELECTRIC COMPANY DELMARVA POWER AND LIGHT COMPANY ATLANTIC CITY ELECTRIC COMPANY SALEM GENERATING STATION. UNIT NO. I DOCKET N0. 50-272 I.
BACKGROUND In January of 1990, Public Service Electric and Gas Company (the licensee) performed a temporary non-code repair on a Salem Unit I service water system ASME Code Class 3 piping due to a leak. The leakage resulted from a 0.8-inch diameter hole in a 24-inch diameter and 1/2-inch thick carbon steel header (11SW).
In May of 1990, as a result of an Integrated Performance Assessment' Program Team Inspection conducted by the NRC, the licensee was questioned about the acceptability of this repair. The staff requested that the licensee submit a request for relief from code repair. By letter dated June 6, 1990,
-the-licensee requested relief from ASME Code repair requirements for the subject 11SW header.
II. EVALUATION OF RELIEF REQUEST Code Requirement Articles IWA-4000 of the Section XI of the code specifies the code repair procedures.
Code Relief Request Relief is requested from the code requirements to repair the 11SW header.
Basis for Relief Article IWA-4000 repair was not practical because the complete isolation of the subject header necessary for the code repair would render a large number of safe shutdown systems inoperable for an extended period due to absence of cooling water.
Proposed Alternative The licensee attached a 1/2-inch thick, 4.5-inch by 5-inch carbon steel pipe patch using a 3/8-inch fillet weld over the pipe flaw. A code repair will be performed during the upcoming ninth refueling outage.
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Staff Evaluation and Conclusion The staff recently issued Generic Letter 90-15, entitled " Guidance for Performing Temporary Non-Code Repair of ASME Code Class 1, 2, and 3 Piping,"
and dated June 15, 1990. As stated in Generic Letter 90-05, the staff continues to find. temporary non-code repairs of code Class 1, 2, and 3 piping unacceptable without specific written relief granted by the NRC. Generic Letter 90-05 also provides guidance that will be considered by the staff in evaluating relief requests submitted by licensees for temporary non-code repairs to code Class 3 piping.
Because the licensee submitted the subject 1
relief request prior the the issuance of Generic Letter 90-05, the staff did not utilize the guidance in Generic Letter 90-05 in evaluating this request.
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The licensee applied a welded patch as a temporary non-code repair.
In reviews relating to Generic Letter 90-05 the staff does not recommend welded patchesasatemporaryrepairbecause(1}weldingmaydamageanyinternalpipe lining, (2) the flaw is hidden by the patch making future inspection difficult, and (3) welding may further degrade the pipe by burn-through of the pipe wall. Nonetheless, the staff finds the repair proposed by the licensee acceptable because (1) a code repair will be performed at the upcoming refueling outage (scheduled for February 1991), (2) the licensee is performing a visual examination of the temporary repair every 3 months, (3) the licensee has determined that flooding resulting from the flawed pipe would be adequately controlled by drainage, flood barriers, and technical specification i
limits, and (4) the licensee has performed stress analysis of the repaired piping indicating stresses are within the code limits.
Future temporary non-code repairs will be reviewed in accordance with Generic Letter 90-05.
The staff has determined that code repair requirements are impractical during operation in that it would render certain safety systems inoperable and code compliance would require plant shutdown. The alternative proposed by the licensee will reasonably assure structural integrity and protect public health and safety.
l Pursuant to 10 CFR 50.55a(g)(6)(1), temporary relief is granted as requested.
This relief.is authorized by law and will not endanger life or property or the coninon defense and security and is otherwise in the public interest, and is g,iven considering the burden on the licensee that could result if the requitements were imposed on the facility.
Dated:
August 29, 1990 L
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