ML17139A910

Board Notification 82-70:notifies of Differing Prof Opinion Re Sensitization of BWR Stainless Steel Weldments

ML17139A910
Person / Time
Site:	Monticello, Susquehanna, Limerick
Issue date:	07/20/1982
From:	Eisenhut D Office of Nuclear Reactor Regulation
To:	Ahearne J, Gilinsky V, Palladino N NRC COMMISSION (OCM)
References
TASK-AS, TASK-BN-82-70 BN--82-70, BN-82-70, NUDOCS 8208060366
Download: ML17139A910 (8)

Text

July 20, 1982 MEMORANDUM FOR:

Chairman Palladino Coranissioner Gilinsky Coomissioner Ahearne Commissioner Roberts Comissi oner Assels tine FROM:

SUBJECT:

Darrell G. Eisenhut, Director Division of Licensing Office of Nuclear Reactor Regulation INFORIQTION ITEtl 'SUSQUEHANNA STEAII ELECTRIC STATION, UNITS 1

5 2

'DIFFERING PROFESSIONAL OPINION RELATED TO SENSITIZATION OF BMR STAINLESS STEEL LlELDMENTS (Board Notification No. 82-7O)

In accordance with present NRC procedures regarding Board Notifications, the enclosed information is being provided for your information as constituting new information relevant and material to safety issues.

This information is generic and has applicability to all dockets with boiling water reactors.

The staff is cunently in the process of trying to satisfactorily resolve a differing professional opinion (DPO) that relates to the adequacy of welding procedures used during fabrication of BtlR reactor vessel internals.

Specifically, General Electric (and/or their subcontractors) have used welding procedures that permitted heat input levels that could cause sensitization of heat affected zones of type 304 stainless steel.

The term "sensitization" is used here to mean that the welded joint would not pass specified ASTtl tests, and therefore, would not be in conformance with specific regulatory positions of Regulatoryi Guide 1.44.

The intent and purpose of Regulatory Guide 1.44 is to ensure that the probability of deleterious intergranular stress corrosion cracking is lots.

Because sensitization is one of the three.factors (high stress, corrosive environment, and sensitization) that must all b'e present to cause intergranular stress corrosion cracking, it is clearly desirable to use welding procedures and other process controls to prevent it.

Nevertheless, the staff'also. believes that even with stringent process specifications, sensitization may not be precluded.

Therefore, in addition to eval:uati ng 'the possibility of sensitization, the staff also considers the probable level of the other I

Contact:

Janis

Kerrigan, ONRR X29788 82080b03bb 820720 PDR ADOCK 05000387 P

PDR SURNAME/. ~..

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The Commission July 20, 1982 two necessary factors for cracking-stress level and environment corrosiveness.

llhile the aggressiveness of BWR water chemistry on sensitized austenitic stainless steel is still the subject of NRC study, the staff's past position has been that both of these factors are relatively 'low at the heat affected areas of welds in BHR internals.

Given the limitations of inservice inspection presently invoked for reactor internals, it is not possible to preclude the existence of cracking; however, the staff's judgment at this time is that the probability of cracking and reactor internals leading to a signsficant failure is low.

The one possible exception to this is the recent cracking found in core spray spargers and related internal piping.

Cracks have been found in Oyster Creek, Peach Bottom'1,'Brunswick 1, and possibly in Pilgrim l.

The staff has determined that the cracking in the affected components does not constitute a serious safety concern.

It is the belief of the party offering this DPO that a review of welding procedures currently used in BWR fabrication and inservice inspection procedures used at currently operating plants, would demonstrate the need for specific inservice inspection of, vessel internals.

It is also the person's belief that it is not an issue involving an immediate safety concern, but one which needs resolution to assure long-term integrity of sensitized BllR components.

o lt" Attached are internal NRC memoranda which discuss the subject DPO.

1<e will continue to actively pursue this matter and notify you of final resolution.

ORIGINAL SIGNED BY:

Darrell G. Eisenhut, Director Division of Licensing Office of Nuclear Reactor Regulation Attachments:

NRC tlemoranda regarding Differing Professional Opinions cc:

ASLB ASLAP SECY OPE OGC Board Service List DISTRIBUTION See Attached OFFICEI SURNAME/

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DISTRIBUTION OF BOARD NOTIFICATION Susquehanna Units 1hZ/COt'le Docket Ho. 50-387/388 Leonard Bickwit, Esq.

Samuel J. Chilk Glenn 0. Bright, Esq.

Dr. John H.

Buck Stephen F.

Ei lperin, Esq.

James P. Gleason, Esq.

Thomas S. Noore, Esq.

Dr. Paul M. Purdom Nr. Robert M. Adler Nr. Thomas Yi. Gerusky llr. Thomas J. Halligan Dr. Judith H. Johnsrud hs. Colleen flarsh G.

Rhodes Jay Silberg, Esq.

t1r. DeMitt C. Smith Bryan A. Snapp, Esq.

Susquehanna Environmental Advocates Atomic Safety and Licensing Board Panel Atomic Safety anC Licensing Appeal Panel Docketing and Service Section Document Vanagement Branch ACRS yEyiBERS Dr. Robert C.

Axtmann Nr. Myer Bender Dr.

Max M. Carbon Hr. Jesse C. Ebersole Hr. Harold Etherington Dr. Milliam Kerr Dr. Harold M. Lewis Dr. 'J.

Carson Viark t1r. Milliam Vi. h1athis Dr. Dade M. Moeller Dr. David Okrent Dr. Hilton S, Plesset f'r. Jeremiah J.

Ray Dr. Paul G.

Shewmon Dr. Chester P. Siess Hr. David A. Mard

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Board Notification t82-7O Susquehanna, Units 1

& 2 Dated July 20, 1982 DIFFERING PROFESSIONAL OPINION RELATED TO SENSITIZATION OF BWR STAINLESS STEEL WELDNENTS Distribution.(W/encl osures)

Document Control (50-387/388)

NRC PDR L PDR PRC System NSIC DL:L Readi.ng*

R. Tedesco/

J. Kerrigan*

D. Eisenhut/R.

Purple M. Williams H. Denton/E.

Case*

PPAS J.

Youngblood A. Schwencer F. Niraglia E.

Adensam H. Bernard R. Vollmer R. Nattson H. Thompson S. Hanauer Attorney, OELD*

ILE Regional Administrator, R-I W. Dircks, EDO (3)*

A. Bennett, OELD (3)

E. Christenbury, OELD*

J. Scinto, OELD R. Perch

• E. Hylton:

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