ML20062H707

Requests Peer Review by 800711 Re Differing Prof Opinion on Weld Repair of Bent Pressurizer Relief Pipe.Forwards Pertinent Documents Dealing W/Repair & W/Issues Concerning Technical (Code) Acceptability.W/O Encl

ML20062H707
Person / Time
Site:	Sequoyah
Issue date:	06/30/1980
From:	Vollmer R Office of Nuclear Reactor Regulation
To:	Shao L NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES)
Shared Package
ML20062H675	List: IR 05000327/1980012 ML20062H670 ML20062H676 ML20062H682 ML20062H690 ML20062H693 ML20062H695 ML20062H700 ML20062H704 ML20062H707 ML20062H710 ML20062H713 ML20062H719
References
NUDOCS 8008210272
Download: ML20062H707 (1)

Text

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I NUCLEAR REGULA TCRY COMMISSION A A$NINGTCN. 3. . 205!$

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'.....~ June 30, 1920 vE.90RANOUM FOR: Lawrence Shao, Assistant Director for General Reactor Safety Resear:n, RES FROM: Richarc H. Volimer, Direc cr Division of Engineering, NRR

SUBJECT:

PEER REVIEW OF A DIFFERING PROFESSICNAL OP!NION As we discussed t: day, ! woul: a::preciate jour ::ncucting a ::eer review of a :iffering professional 0;inien relative to a neld repair of a :ent

ressuri:er relief ; ice on Secuoyah Unit 1. Tc assist you in this review,

! am enclosing a pacxage of :ertinent documents dealing with the pressuri:er line repair itself and witn the issues that nave surfaced concerning the taennical (coce) acce::acility anc the potantial for future line degradation f-:= lGSSC.

is: included in this :ackage are One ;clicy and :rece ures f:r dif'ering

ro fessional c;inions nic . nave been a:Oroved :y :ne ;cmmission. These

r:cecures cali f:r an ex::edi:ec resolution. I recuest that your review

e ::meletec :y *uly 11, 1980. If :nis is net feasi::le : lease let me knew.

T9e use of a :eer review grou: to assist in :ne process cf resolution Of a

iffering ;r:fessienal ::ini:n is discussed in Section 3.: cf :ne a:cve er. icnec :rececures. NRR will be ha::y :: assist you in :nis process anc aill maKe availa le for ciscussion witn your grou: ali perscns so far involve , Or any ::ner indivi:ual you suggest.

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,/ Ri c narc. 'M. Vollmer, Oirector Division of Engineering Of'ica Of Nuclear Reac:Or Pegula: On En: :sures: As s a:ad

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%, . p JUL 2 1980 MEMORANDUM FOR: Harold R. Denton, Director, NRR FROM: Richard H. Vollmer, Director, DE

SUBJECT:

DIFFERING PROFESSIONAL OPINION CONCERNING REPAIR OF PRE 55URIZER RELIEF PIPE AT SEQUOYAH UNIT ONE This is to advise you of the status of resolution of a differing professional opinion submitted by Mr. Halapatz of the Materials Engineering Branch concerning the subject line repair. As background, the pressurizer line was bent during the hot functional testing of Sequoyah Unit One last year wnen a pipe support failed to yield when the system heated up. As a result of tnis the pipe was de formed. TVA proceeded to perform a repair on the pipe which consisted of grooving the pipe in two places and inducing a shrinkage by weld repair. As a result, the pipe was straigt.tenec. This repair had been given extensive review by NRR and I&E as a result of two principal concerns raised by Mr. Halapat::

1. He feels that it is not possible to conclusively demonstrate by the evidence in hand that the pipe was not penetrated during the repair operation. If the pipe had been penetrated, the code would require that a hydro test of tne system be performed.

2. he is concerned that the welding repair has sensitized that region of the pipe to make it susceptible to intergranular stress corrosion cracking. He feels that this could threaten the integrity of the primary system during plant operation.

Althoagh NRR and I&E have concluded that the repair is acceptable from a code standpoint and does not pose a safety problem, Mr. Halapat: expressed a differ-ing professional opinion by the enclosed memo dated June 16, 1980.

In an effort to resolve this dii'fering opinion, I have met with both my staff and Mr. Halapat: separately on two occasions. Based on these meetings and on a review of the infomation available, I have tentatively concluded that any Dessible safety concerns would be satisfactorily addressed if an augmented inservice inspection program, as recommended by Mr. Noonan, is imolementec.

I believe that this would make a failure of this pipe as or more unlikely than any other location in the primary system pressure boundary.

In order to supplement my judgment on this problem, however, I have recently asked Larry Shao of Researen to perform a peer review of the issues leading to this differing professional opinion and give me a peer recommendation on appropriate actions. I have requestec Mr. Shao to complete this review by N6vtk67

Harold R. Denton JUL 2 7980 July 11 so that I can give you my final recommendation promptly in accordance with the Commission procedures on resolution of differing professional opinions. The end date for your resolution is July 16th -- 30 days from Mr. Halapatz' original memorandum on the subject. If additional time is required, either by peer review or your review, an additional 15 days is allowed in these procedures.

I would be happy to arrange for a briefing on the issues at your convenience.

Richard H. Vollmer-Director Division of Engineering

Enclosure:

Memo - Halapat to Pawlicki dtd 6/15/80 cc: w/ encl.

E. Case J. Halapatz i

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