ML20054G464
| ML20054G464 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 06/07/1982 |
| 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 8206210581 | |
| Download: ML20054G464 (2) | |
Text
., '
.)
TEgSSEE VALLEY AUTHORITY N ' CN TA[
NESSEE 374ol 400 Chestnut Street Tower II 82 JUN 9 A8 2IJune 7, 1982 BLRD-50-438/81-56 BLRD-50-439/81-58 U.S. Nuclear Regulatory Commission Region II Attn:
Mr. James P. O'Reilly, Regional Administrator 101 Marietta Street, Suite 3100 Atlanta, Oeorgia 30303
Dear Mr. O'Reilly:
BELLEFONTE NUCLEAR PLANT UNITS I AND 2 - RCS SUPPORTS AND RESTRAINTS -
BOLT TORQUES - BLRD-50-438/81-56, BLRD-50-439/81 FOURTH INTERIM REPORT The subject deficiency was initially reported to NRC-0IE Inspector R. V. Crlenjak on August 24, 1981 in accoraance 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 and March 10, 1982. Enclosed is our fourth interim report. We expect to submit our next report by December 15, 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 VALLEY AUTHORITY L M M:lkLj oss L. M. Mills, Manager Nuclear Licensing 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 ohhh[j8 D
[ ff An Equal Opportunity Employer
I ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 RCS SUPPORTS AND RESTRAINTS - BOLT TORQUES NCR BLN NES 8111 BLRD-50-438/81-56, BLRD-50-439/81-58 10 CFR 50.55(e)
FOURTH 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 Ccolant 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 (7 120 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, No. NEB 810825 627 dated August 19, 1981) that they had reported to the NRC, under the require-ments of 10 CFR Part 21, concerns that B&W has with regard to stress corrosion cracking of high strength bolting material.
Interim Progress TVA is still in the process of evaluating this NCR. More information will be available once B&W has developed acceptance criteria for bolting of this type.
e