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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COMMISSION

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

DOflKET Fl! E COPY 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-clear Reactor Regulation, U.S. Nu-clear Regulatory Commisson, Wash-ington. D.C. 20555. (Phone: 30142-V221)SUPPLEMENTARY

INPORMATION:

In 1975, a Pipe Cracking Study Group was established by the United States Nuclear Regulatory Commission (USNRC) to review intergranular stress-corrosion cracking (ISCC) in Boiling Water Reactors (BWRs). The Group reported its findings concern-tng stress-corrosionl cracking in by-pass tines and core spray piping of austen-tic stainless steel In a report, Techni-cel Report-Investigation and Evalua-ffon of Cracking in Austenitic Stain-inss Steel Piping of Boiling Water Re-actor Plants (NUREG-75/067).

During 1978. IGSCC was reported for the first time in large-diameter piping in a BWR. This discovery, to-gether with questions concerning the capability of ultrasonic detection methods to detect snl cracks. led to the formation of a new Pipe Crack Study Group (PCSG) by USNRC on September

14, 1978.The charter of the new PCSO was to specifically address the five following questions:

I1. The significance of the cracks discovered in large-diameter pipes rel-ative to the conclusions and recom-mendations set forth in the referenced report (NUREG-75/067)

and its imple-mentation document.

NUREG-0313;

2. Resolution of the concerns raised over the ability to use ultrasonic tech-niques to detect cracks In austenitlc tainless steel: 3. The significance of cracks found in large-diameter sensitized safe ends and any recommendations regarding the current NRC program for dealing with.this matter.4. The potential for stress corrosion cracking in PWRs: 5. Examine the significance of crack-lng in the Inconel safe ends that has been experienced at the Duane Arnold Operating Facility, and develop any recommendations regarding KRC ac-tions taken or to be taken." The PCSG limited the scope of the study to BWR and PWR piping and safe ends attached to the reactor pres-sure vessel. The PCSG reviewed exist-Ing Information-either that contained In written records or that collected through meetings In this country and in foreign countries.

The specific areas considered are presented In the chap-ters of this report:* BWR Cracking Experience and Corrective Actions* PWR Cracking Experience and Corrective Actions* Metallurgy Associated

1with Pipe Cracking* Reactor Coolant Chemistry* Pipe Configuration and 8rs Levels* Duane Arnold Safe-End CrWking* Methods of Detecting Cracks* Sign]iicance of Cracks* Recent Development Relevant to Control and Detection of IQSCC The review of these topics In the context of changes occurring since the preparation of NUREG-75/067 led to the preparation of specific conclusions and recommendations relevant to the current status of IGSCC. the signifl-eance of the problem, and the reliabil-ity of detection and measures available to correct or minimize ISCC In exist-ing and future plants. These conclu-sions and recommendations are pre-sented in the newly Issued PCSG report.The NRC staff WllM review the Study Group report and its conclusions/rec- ommendations and the public com-ments received during this comrnent period. Following this review, the staff will decide what further actions If any, are required for the licenaing and operation of reactors.Requests for a single copy of the report should be made in writing to U.S. Nuclear Regulatory Commission, Washinto.

D.C. 20555. Attention Di-rector. Division of Technical Informa-tIon and Document ControL Comments on this report should be sent to the Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission.

Washington.

D.C. 20555.Attention:

Duputy Director.

DIvision of Operating Reactors.

The comment period expires May 15. 1979. Copies of all comments received will be available for examination In the Commission's Public Document Room. 1711 I Street, l.W. Washington, D.C.Dated at Bethesda, Md. this Sth day of March 1979.For the Nuclear Regulatory Oom-mission.Vicrox SELLO. Jr.Director, Division of Operating Reactors, Office of Nuclear Re-actor Regulafion.

CM Doc. 714705 Fuled 3-12-79; :45 m)[7590-1-MI

DOMESTIC LICENSING

OF PRODUCTION

AND UTILIZATION

FACLITES*Ivestigaton end Evokmation of Strss Conoslon Cracking in Piping of Ught Water Readtr Plants AGENCY: U.S. Nuclear Regulatory Commission.

ACTION: Request for public comment on NUREG-0531 "Investigation and Evaluation of Stress Corrosion Crack-Ing In Piping of Light Water Reactor Plants" February 1979.SUMMARY: On September

14, 1978.the Nuclear Regulatory Commission established a new Pipe Crack Study Group. The Group was to evaluate recent pipe and safe end cracking ex-perience relative to previous staff con-cluslons and recommendations.

The NRC seeks public comment on the report which summarizes the Group's review and conclusions.

DATES: The public comment period expires May 15, 1979.FOR FURTHER INFORMATION

CONTACT

Darrell 0. Eisenhut, Deputy Direc-tor for Operating Reactors, Division 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.