ML20042A459
| ML20042A459 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 03/10/1982 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| REF-PT21-82 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8203230453 | |
| Download: ML20042A459 (2) | |
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TENNESSEE VALLEY AUTHORITY CH ATTANOOGA, TENNESSEE 374ot U;
400 Chestnut Street Tower II 2'
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March 10, 1982
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BLRD-50-438/81-56 ff BLHD-50-439/81-58 q,
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-C U.S. Nuclear Regulatory Commission
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NARg Region II 6
itPc @ g2b Attn:
Mr. James P. O'Reilly, Regional Administrator da Qp 101 Marietta Street, Suite 3100 Cd Atlanta, Georgia 30303
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Dear Mr. O'Reilly:
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BELLEFONTE NUCLEAR PLANT. UNITS 1 AND 2 - RCS SUPPORTS AND RESTRAINTS -
BOLT TORQUES - BLRD-50-438/81-56, BLRD-50-439/81 THIRD INTERE REPORT The subject deficiency was initially reported to NRC-0IE Inspector R. V. Crlenjak on August 24, 1981 in accordance with 10 CFR 50.55(e) as NCR BLN NEB 8111. This was followed by our interim reports dated September 24 and December 7, 1981.
Enclosed is our third interim report.
We expect to submit our next report by June 10, 1982. We consider 10 CFR Part 21 applicable to this deficiency.
If you have any questions concerning this matter, please get in touch with R. H. Shell at FTS 858-2688.
Very truly yours, TENNESSEE VAL, LEY AUTHORITY O g $e s). a L. M. Mi Is, Manager <
s,g Nuclear Regulation and Safety Enclosure cc:
Mr. Richard C. DeYoung, Director (Enclosure)
Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555 Mr. James McFarland (Enclosure)
Senior Project Manager Babcock & Wilcox Company P.O. Box 1260 Lynchburg, Virginia 24505 OFFICIAL CO%
8203230453 820310 DR ADOCK 05000 An Equal Opportunity Employer L
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ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 RCS SUPPORTS AND RESTRAINTS - BOLT TORO,2S BLRD-50-438/81-56, BLRD-50-439/81-;)
~ THIRD INTERIM REPORT Description of Deficiency Babcock & Wilcox (B&W), Lynchburg, Virginia, specified ASME SAS40 Class I and 2 material and a preload of 70 percent of ultimate tensile strength for many of the Reactor Coolant System (RCS) anchor bolts for supports and restraints. These materials have a minimum yield strength of 150 kai and 140 kai, respectively. Recently, it has been documented that stress corrosion cracking (SCC) is a potential failure mode for high yield strength (
120 ksi) low alloy steel bolting material subjected to appreciable steady state loads (generally preload in the case of supports and restraints) and typical reactor containment corrosive environments (humid air or borated water on occasion) for extended periods of time.
B&W notified TVA (in B&W letter to TVA, L'o. D-3871 OI 0045-18 dated August 19, 1981) that they had reported to the NRC, under the require-ments of 10 CFR Part 21, concerns that B&W h3s with regard to stress corrosion cracking of high strength bolting material.
Interim Progress TVA is still in the process of reviewing the B&W position regarding stress corrosion cracking (SCC) of high strength bolting material. At this time, TVA does not agree with B&W that all bolting greater than 120 kai yield strength is subject to SCC. TVA'has begun c program to survey the Reat:or Coolant System material properties and is investigating minimum required loading conditions. This work is being done so that TVA will be able to address the high strength low alloy (HSLA) bolting SCC issue when acceptance requirements are defined by the NRC. To date, however, such acceptance requirements have not been de fined. We expect to supply you with more information on this item in our next report.
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