ML17286A888

Provides Info Re Missed VT-1 Insp of Jet Pump Hold Down Beams at Facility During Sixth Refueling Outage,Caused by Oversight by Individuals Who Prepared,Reviewed & Approved Exam Plan for Inservice Visual Exams

ML17286A888
Person / Time
Site:	Columbia
Issue date:	06/12/1991
From:	Sorensen G WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GO2-91-119, NUDOCS 9106190300
Download: ML17286A888 (5)

Text

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ACCELERATED DIS UTION DEMONS ON SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9106190300 DOC.DATE: 91/06/12 NOTARIZED- NO DOCKET

, FACIL:50-397 WPPSS Nuclear Project, Unit 2, Washington Public Powe 05000397 AUTH. NAME AUTHOR AFFILIATION SORENSEN,G.C. Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

Provided info re missed VT-1 insp of jet pump hold down beams at facility during sixth refueling outage, caused by oversight by individuals who prepared, reviewed & approved exam plan for inservice visual exams.

DISTRIBUTION CODE A047D COPIES RECEIVED LTR ENCL SIZE-TITLE: OR Submittal: Inservice Inspection/Testing/Relief from ASME Code NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA PD5 PD ENG,P.L.

INTERNAL: ACRS AEOD/DS P/TPAB NRR/DET/ECMB 9H NRR/DET/EMEB 7E NUDOCS-ABSTRACT OGC/HDS1 REG FILE 01 RES/DSIR/EIB EXTERNAL EG&G BROWN i B EG&G RANSOME,C NRC PDR NSIC R

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D NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED: LTTR 22 ENCL

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WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O. Bccc 96'8 ~ 3000 George Wasbtngton Way ~ Rtcbland, Wasbtngton 99352496'8 ~ (509) 372-5000 June 12, 1991 G02-91-119 Docket No. 50-397 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555 Gentlemen:

Subject:

NUCLEAR PLANT NO. 2, OPERATING LICENSE NPF-21 CRACKING OF BMR JET PUMP HOLD DOMN BEAMS

Reference:

Letter, G02-80-279, GD Bouchey to RL Tedesco, same subject, dated December 4, 1980 The purpose of this letter is to provide information regarding the missed VT-1 inspection of the jet pump hold down beams at WNP-2 during the sixth refueling outage. This inspection was initially performed during the fourth refueling outage with a reinspection frequency of two years as described in the WNP-2 10 year ISI Plan. This problem was noted internally via a Plant Problem Report (PER 291-499) with the following resolutions:

1) Perform the VT-1 inspections at the next refueling outage (R7).

2) Review responsibilities of implementation of the ISI Outage Plan with the ISI Program Leader, Task Leaders and ISI Engineer.

3) Include in the ISI Summary Report a description of the examination program, its status and commit to performing the VT-1 exam during the R7 outage.

4) Discuss the condition with the NRC Resident Inspector.

The root cause of this problem was an oversight by those individuals who prepared, reviewed and approved the Examination Plan for Inservice,Visual Examinations of WNP-2 RPV Internals for Refueling Outage R6. The requirements for a visual examination of the jet pump beams appears in the 10 year ISI Plan for WNP-2 and that document serves as the reference point 'for the development of annual examination plans. The Supply System will rectify this problem by revising internal procedures before the next outage to more clearly delineate responsibilities of the three groups who are involved in the review/approval process.

9i06f90300 9i06i2 0 '000397 PDR ADOCK PDR 9

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':CRACKIIG OF BWR JET PUMP HOLD DOWN BEAMS Upon review of the technical requirements that led to specification of a VT-1 exam of these beams, it was determined that such exams are not required, even though they are specified in the 10 year ISI Plan. The initial requirement for examination of BWR jet pump hold down beams was provided in IE Bulletin 80-07, dated April 4, 1980 for plants in operation. At that time, both UT and VT exams were required. On June 9, 1980 GE's SIL-330 was issued recommending only a UT exam be performed. Later that year (December 4, 1980) the Supply System notified the NRC (Reference 1) that their Inconel X-750 jet pump beams were detensioned to a 25 kip preload to avoid the stress corrosion cracking concerns identified in IE Bulletin 80-07 and SIL-330. In December 1981, GE issued NEDE-24362-1 entitled "Improvements in Jet Pump Hold Down Beam Service Life". This document recommended UT only on beams in BWR/4-6 with original heat treatment and a 25 kip preload, the category in which WNP-2 fits. The last report on this issue was NUREG/CP 3052 entitled "Closeout of IE Bulletin 80-07: BWR Jet Pump Assembly Failure", issued in November 1984. This document repeated GE's December 1981 recommendation of UT only on the beams with the first exam at five years and subsequent exams at two year intervals thereafter. In all of the above GE reports, there were no requirements for VT-1 or VT-3 exams of the jet pump beams.

The Supply System's 10 year ISI Plan was developed during the same time frame (1980 - 1984) when the requirements were evolving for exam of jet pump beams.

Therefore, what appears in the 10 year ISI Plan, with today's knowledge, appears to be conservative. The Supply System has indeed complied in full with the UT requirements by completing the first exam at R4 and again at R6. In addition, GE, who performed the exams during R4 and R6, also conducted a VT-3 type exam of the beams. No problems were noted in either case.

Finally, a recent assessment by GE (SASR-91-01, dated April 1991) entitled "Prioritization of BWR Internals and Attachments for Detailed Repair Development" concludes that the susceptibility for cracking and consequences of cracking are both low for BWR/4, 5 and 6. Reasons cited include prior steps taken to mitigate the chances for stress corrosion cracking, e.g., detensioning the preload on the beams from 30 kips to 25 kips.

In conclusion, the Supply System has determined that there are no technical concerns or safety issues associated with the missed VT-1 exam of its jet pump beams at WNP-2. In comparing R6 ISI results with the Annual ISI Plan commit-ments, as is normally done each outage, no other problems were detected. The administrative problems have been identified and internal steps are being taken to preclude reoccurrence of that type of problem on the ISI program.

Very truly yours, G. C. S rensen, Manager Regulatory Programs RAM/bk cc: JB Hartin - NRC RV NS Reynolds - Winston 8 Strawn PL Eng - NRC DL Williams - BPA/399 NRC Site Inspector - 901A

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