ML20024F140

Responds to NRC 830617 Ltr Re Violations Noted in IE Insp Rept 50-275/83-20.Corrective Actions Described in 830627 Response to 830526 Ltr Applicable to Violation

ML20024F140
Person / Time
Site:	Diablo Canyon
Issue date:	07/15/1983
From:	Schuyler J PACIFIC GAS & ELECTRIC CO.
To:	Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
Shared Package
ML20024F136	List: ML20024F140
References
NUDOCS 8309080256
Download: ML20024F140 (4)

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PACIFIC GAS AND E LE C T RIC C O M PANY PGwE j 77 scAtt sinccr . san rnancisco, catironnir 94tes . <4:s> 7si.42ii . :WX 9:0 372 6587 J.O.SCHUYLER vict entsspant 4WCLEAR POetR Gretaat#O4 July 15, 1983 Mr. John B. Martin, Regional Wnistrator U.S Nuclear Regulatory Comnission, Region V 1450 Maria Iane, Suite 210 Walnut Creek, CA 945 % -5368 Re: Docket No. 50-275, OL-DPR-76 Diablo Canyon Unit 1 IE Inspection Report 50-275/83-20-- Notice of Violation

Dear Mr. Mattin:

MlC Inspection Report 50-275/83-20, dated June 17, 1983, included a Severity level IV Notice of Violation for Unit 1. PGandE's response to this Notice is enclosed.

Sincerely, Ad Enclosure ccw/ enc: Service List l

l 8309000256 030901 PDR ADOCK 05000275 o PDR 63-107

7 PGandE'S RESPONSE 'ID IUTICE OF VIDIATIN IN IRC'S INSPECTIN RERRT 50-275/83-20 On June 17, 1983 IRC Region V issued a Severity Ievel IV Notice of Violation

(" Notice"), as part of MtC Inspection Report 50-275//83-20 on Diablo Canyon Unit 1. 'Ibe Notice cited a concern related to the timeliness of the reporting of an apparent finding that certain areas on a girth weld, WIB-RC-2-17, on the cold leg of reactor coolant loop 2 did not meet the specified miniatun wall thickness requirements. 'Ihis apparent condition was first identified in December, 1982 and was reported to the IRC on May 10, 1983. 'Ibe violation was described in the Notice as:

rechnical Specification 6.9.1.11 states, in part, that the REKRTABE OCClRRENCES of Specifications 6.9.1.12 and 6.9.1.13 below, including corrective actions and measures to prevent recurrence, shall be reported to the IRC...

Technical Specification 6.9.1.12 lists the types of events which shall be reported by telephone within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to the Director of the Regional Office, or his designate, and confirmed by telegram, mailgram or facsimile no later than the first working day following the event, with a written followup report within 14 days.

Technical Spacification 6.9.1.12.1 describes a type of event which shall be reported pursuant to Technical Specification 6.9.1.12 and states as follows:

'Berformance of structures, systems, or couponents that requires reunedial action or corrective measures to prevent operation in a manner less conservative than asstuned in the accident analyses in the safety analysis report or Technical Specifications bases; or discovery during unit life of conditions not specifinally considered in the safety analysis report or Technical Specifications that require remedial action or corrective measures to prevent the existence or development of an unsafe condition.'

Contrary to the above requirements, on Dw=her 17,1%2, the licensee identified that certain areas on Weld No.

WIB-RC-2-17 were less than the minimian wall thickness specified by desf6n and the applicable codes. Weld No.

win-RC-2-17 is in loop No. 2 of the Reactor Coolant System. 'lhis condition was not reported to the IRC until May 10,1%3."

Discussion The concern regarding mini == wall thickness was originally raised as a result of ultrasonic (W) miiasurements made in h amber, 1982 to supplement preservice inspection data. The original W measurements were made with the intention of generating contour plots of the weld root counterbore surface to identify possible geometric reflectors that might produce anomalous indications in future inservice inspections. For this purpose, the axial variation in thickness is more important than the absolute value of thickness.

After extensive investigations were conducted on this subject and documented in a report transmitted to the Mtc on July 5,1983, we concluded that the W measurements lack the precision required for absolute measurement of reactor coolant loop weld thickness after the piping was installed.

The essence of this violation, however, is not whether the W measurements are, or are not, shown to be reliable for this application, but, rather, involves whether or not the occurrence was handled properly in accordance with established procedures for doctanenting and resolving potential nonconformances. This is succinctly stated on page 5 of IRC Inspection Report 50-275/83-20:

"Iherefore, as the previously presented chronology of licensee actions indicate that by kamher 13, 1982*

appropriate levels of plant management were infonned of the discrepancy. In addition, on December 17,1982 a Nuclear Plant Problem Report No. DCI-82-QC-P0300 was written describing the discrepant condition, though it was

not rted at this time as a condition requiring a Imance report. It appears that sufficient evidence was available at this time to warrant issuance of a nonconformance report. If a nonconformance had been written the Technical Review Group would have been required to review the discrepant condition for reportability under the Technical Specifications."

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• This date is shown as "1983" in the Inspection Report.

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t We concur that the problan should have been doctanented in a Nonconformance Report in ha=1=r,1%2. At the very least, this would have led to a more timely investigation of the type recently conducted, and a more thotshtful evaluation of reporting implications.

'Ihe general subject of the handling of potential nonconformances and their reporting has been given considerable recent attention as a result of the manner in which the reactor coolant loop gotging incident was reported in April, 1983. As a result of a one-day delay in reporting this occurrence, PGandE received a Severity level V Notice of Violation dated May 26, 1983.

FGandE's response to this Notice of Violation, dated June 27,1%3, described corrective steps taken to improve the areas of nonconformance reporting and investigation. 'Ihe corrective action described in that response is applicable to this violation as well.

Corrective Steps Which Will be Taken to Avoid Rarther Items of hemvliance Based on the actions described above and already implemented, PGandE believes

that =4mte corrective action has been taken. 'Iherefore, no additional corrective steps are necessary.

Date of Pb11 Compliance Rill compliance has already been achieved.

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