ML20070F807
| ML20070F807 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 12/13/1982 |
| 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 8212210256 | |
| Download: ML20070F807 (2) | |
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TENNESSEE VALLEY AUTHORITY CHATTANOOGA. TENNESSEE 374ot 400 Chestnut Street Tower II December 13, 1982 BLRD-50-438/81-56 y
BLRD-50-439/81-58
. x.
O O
U.S. Nuclear Regulatory Coinnission E
'T Region II Attn:
Mr. James P. O'Reilly, Regional Administrator y
101 Marietta Street, Suite 3100 Atlanta, Georgia 30303 c.c
Dear Mr. O'Reilly:
BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - RCS SUPPORTS AND RESTRAINTS -
BOLT TORQUES - BLRD-50-438/81-56, BLRD-50-439/81 FIFTH INTERIM REPORT The subject deficiency was initially reported to NRC-OIE 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 and March 10 and June 7, 1982. Enclosed is our fifth interim report. We expect to submit our next report by June 30, 1983 We consider 10 CFR Part 21 applicable to this deficiency.
This deficiency has also been reported for Watts Bar and Yellow Creek Nuclesr Plants as NCR GEN NEB 8201.
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. Mills, Manager Nuclear Licensing Enclosure cc:
Mr. Richard C. DeYoung, Director (Enclosure)
Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Mr. James McFarland (Enclosure)
Senior Project Manager Babcock & Wilcox Company P.O. Box 1260 Lynchburg, Virginia 24505
. OFHCIAL COJ1,3
$5N"EE88?of8s8ise e 17 PDR An Equal Opportunity Employer
ENCLOSURE l
BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 RCS SUPPORTS AND RESTRAINTS - BOLT TORQUES l
NCR BLN NEB 8111 BLRD-50-438/81-56, ' BLRD-50-439/81 -58 10 CFR 50.55(e)
FIFTH INTERIM REPORT Description of Deficiency Babcock & Wilcox (B&W),_ Lynchburg, Virginia, specified ASME SA540 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 crheking (SCC) is a potential failure mode for high yield strength C5120 kai) 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 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 ksi yield strength is subject to SCC. TVA has begun a program to survey the Reactor 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.
The NRC has indicated that they expect to have a technical position established early in the spring of 1983 TVA is working actively with the AIF/MPC Task Group on bolting to establish an industry position on the various bolting issues to satisfy industry and NRC concerns with SCC.
More information will be forwarded in our next report.
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