NRC Generic Letter 1979-14

NRC Generic Letter 1979-014: NUREG-0531 Investigation and Evaluation of Stress Corrosion Cracking in Piping of Light Water Reactor Plants February 1979

ML031320266
Person / Time
Issue date:	03/15/1979
From:	Grimes B Office of Nuclear Reactor Regulation
To:
References
NUREG-0531, NUREG-75/067 GL-79-014
Download: ML031320266 (3)

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10ANUCLEAR REGULATORY COMMISSION

WASHINGTON, D. C. 20555 p March 15, 1979 G -L-9- f ALL POWER REACTOR LICENSEES

REGULATORY DOflKET Fl! ECOPY

Gentlemen:

On September 14, 1978, the Nuclear Regulatory Commission established a new Pipe Crack Study Group which was to evaluate recent pipe and safe end cracking experience relative to previous staff conclusions and recommendations. The bases for establishing the new Study Group were

(1) the discovery of cracks in the inner surface of large-diameter austenitic stainless steel piping (recirculation lines) in a BWR and

(2) questions concerning the capability of ultrasonic detection methods to detect small cracks.

The new PCSG reviewed existing information that either was contained in'

written records or had been collected through meetings in this country and in foreign countries. The review was in the context of changes occurring since the preparation by the original Pipe Cracking Study Group of NUREG-75/067 "Technical Report--Investigation and Evaluation of Cracking in Austenitic Stainless Steel Piping of Boiling Water Reactor Plants". The conclusions and recommendations of the new Pipe Crack Study Group are presented in the enclosed "Investigation and Evaluation of Stress Corrosion Cracking in Piping of Light Water Reactor Plants", NUREG-0531.

This report is for your information and comment. Also enclosed is a copy of a related Federal Register Notice.

The NRC staff will review the Study Group report and its conclusions/

recommendations and any comments received about the report. Following this review, the staff will decide what further actions, if any, are required for the licensing and operation of reactors.

Sincerely, L

Brian K. Grimes, Assistant Director for Engineering and Projects Division of Operating Reactors Enclosures:

1. NUREG-0531

2. Notice C162

4 of Operating Reactors. Office of Nu-

• Pipe Configuration and 8rs clear Reactor Regulation, U.S. Nu- Levels clear Regulatory Commisson, Wash-

• Duane Arnold Safe-End CrWking ington. D.C. 20555. (Phone: 30142-

• Methods of Detecting Cracks V221)

• Sign]iicance of Cracks SUPPLEMENTARY INPORMATION:

• Recent Development Relevant to In 1975, a Pipe Cracking Study Group Control and Detection of IQSCC

was established by the United States The review of these topics In the Nuclear Regulatory Commission context of changes occurring since the (USNRC) to review intergranular preparation of NUREG-75/067 led to stress-corrosion cracking (ISCC) in the preparation of specific conclusions Boiling Water Reactors (BWRs). The and recommendations relevant to the Group reported its findings concern- current status of IGSCC. the signifl- tng stress-corrosionl cracking in by-pass eance of the problem, and the reliabil- ity of detection and measures available tines and core spray piping of austen- to correct or minimize ISCC In exist- tic stainless steel In a report, Techni- cel Report-Investigation and Evalua- ing and future plants. These conclu- ffon of Cracking in Austenitic Stain- sions and recommendations are pre- sented in the newly Issued PCSG

inss Steel Piping of Boiling Water Re- report.

actor Plants (NUREG-75/067). The NRC staff WllM review the Study During 1978. IGSCC was reported Group report and its conclusions/rec- for the first time in large-diameter ommendations and the public com- piping in a BWR. This discovery, to- ments received during this comrnent gether with questions concerning the period. Following this review, the staff capability of ultrasonic detection will decide what further actions If methods to detect snl cracks. led to any, are required for the licenaing and the formation of a new Pipe Crack operation of reactors.

Study Group (PCSG) by USNRC on Requests for a single copy of the September 14, 1978. report should be made in writing to The charter of the new PCSO was to U.S. Nuclear Regulatory Commission, specifically address the five following Washinto. D.C. 20555. Attention Di- questions: rector. Division of Technical Informa- I1. The significance of the cracks tIon and Document ControL

discovered in large-diameter pipes rel- Comments on this report should be ative to the conclusions and recom- sent to the Office of Nuclear Reactor mendations set forth in the referenced Regulation U.S. Nuclear Regulatory report (NUREG-75/067) and its imple- Commission. Washington. D.C. 20555.

mentation document. NUREG-0313; Attention: Duputy Director. DIvision

2. Resolution of the concerns raised of Operating Reactors. The comment

[7590-1-MI over the ability to use ultrasonic tech- period expires May 15. 1979. Copies of DOMESTIC LICENSING OF PRODUCTION AND niques to detect cracks In austenitlc all comments received will be available UTILIZATION FACLITES tainless steel: for examination In the Commission's

3. The significance of cracks found Public Document Room. 1711 I

• Ivestigaton end Evokmation of Strss in large-diameter sensitized safe ends Street, l.W. Washington, D.C.

Conoslon Cracking inPiping of Ught Water and any recommendations regarding Readtr Plants Dated at Bethesda, Md. this Sth day the current NRC program for dealing of March 1979.

AGENCY: U.S. Nuclear Regulatory with.this matter.

4. The potential for stress corrosion For the Nuclear Regulatory Oom- Commission. cracking in PWRs: mission.

ACTION: Request for public comment 5. Examine the significance of crack- Vicrox SELLO. Jr.

on NUREG-0531 "Investigation and lng in the Inconel safe ends that has Director, Division of Operating Evaluation of Stress Corrosion Crack- been experienced at the Duane Arnold Reactors, Office of Nuclear Re- Ing In Piping of Light Water Reactor Operating Facility, and develop any actorRegulafion.

Plants" February 1979. recommendations regarding KRC ac- CM Doc. 714705 Fuled 3-12-79; :45 m)

SUMMARY: On September 14, 1978. tions taken or to be taken."

the Nuclear Regulatory Commission The PCSG limited the scope of the established a new Pipe Crack Study study to BWR and PWR piping and Group. The Group was to evaluate safe ends attached to the reactor pres- recent pipe and safe end cracking ex- sure vessel. The PCSG reviewed exist- perience relative to previous staff con- Ing Information-either that contained cluslons and recommendations. The In written records or that collected NRC seeks public comment on the through meetings In this country and report which summarizes the Group's in foreign countries. The specific areas review and conclusions. considered are presented In the chap- ters of this report:

DATES: The public comment period

• BWR Cracking Experience and expires May 15, 1979. Corrective Actions FOR FURTHER INFORMATION

• PWR Cracking Experience and

CONTACT

Corrective Actions Darrell 0. Eisenhut, Deputy Direc-

• Metallurgy Associated 1with Pipe tor for Operating Reactors, Division Cracking

• Reactor Coolant Chemistry FEDERAL AWASTM VOL 4, NO. SO-TUNDAY, MUAC 13t 1979

'\ - ;

Mr. William J. Cahill, Jr.

Consolidated Edison Company of New York, Inc.

cc: White Plains Public Library

100 Martine Avenue White Plains, New York 10601 Joseph D. Block, Esquire Executive Vice President Administrative Consolidated Edison Company of New York, Inc.

4 Irving Place New York, New York 10003 Edward J. Sack, Esquire Law Department Consolidated Edison Company of New York, Inc.

4 Irving Place New York, New York 10003 Anthony Z. Roisman Natural Resources Defense Council

917 15th Street, N.W.

Washington, D. C. 20005 Dr. Lawrence R. Quarles Apartment 51 Kendal at Longwood Kennett Square, Pennsylvania 19348 Theodore A. Rebelowski U. S. Nuclear Regulatory Commission P. 0. Box 38 Buchanan, New York 1051.