ML20010J287
| ML20010J287 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 09/24/1981 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| REF-PT21-81 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8109300259 | |
| Download: ML20010J287 (2) | |
Text
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TENNESSEE VALLEY AUTHCRIT't CH ATTANCOGA. TENNESSIE 37401 400 Chestnut Street Tower II
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t September 24, 1981 BLRD-50-438/81-56
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BLRD-50-439/81-58 g P' {
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h Mr. James P. O'Reilly, Director 7 "S g p g g I98I b Office of Inspecticu and Enforcement 9
U.S. Nuclear Regulatory Commission p
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Region II - Suite 100 e,
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101 Mariette Streec Atlanta, G4crgia 30303
Dear Mr. O'Reilly:
BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - RCS ?UPPORTS AND RESTRAINTS -
BOLT TORQUES - BLRD-50-438/81-56, BLRD-50-439/81 FIRST INTERIM REPORT The subject deficiency was initially reported to NRC '*E Inspector R. V. Celenjak on August 24, 1981, in accordance witu 10 CFR 50.55(e) as NCR BIR NEB 8111. Enclosed is our first interim repart. We expect to i
submit our next report by December S, 1981. We consider 10 CFR Part 21 to be apr.licable to this deficiency.
If you have any questions concerning this matter, please get in touch I
with D. L. Lambert at MS 857-2581.
Very truly yours, TENNESSEE VALLEY AUTHORITY
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jjl,f L. M. Mills, Manager Nuclear Regulation and Safety l
Enclosure ec: Mr. Victor Stello, Jr., Director (Enclosure)
Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washiraton, DC 20555 Mr. James McFarland (Enclosure)
Senior Project Manager Babcock & Wilcox Company h
P.O. Box 1260 g
Lynchburg, VA 24505 l
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'8109300259 810924 PDR ADDCK 05000438 PDR.
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ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 RCS SUPPORTS AND RESTRAINTS - BOLT TORQUES BLRD-50 43'l/81-56, BLRD-50-439/81-53 E3T INTERIM REPORT Deser iphon of__ Deficiency Babcock & Wilcox (B&W), Lynchburg, Virginia, specified ASME SA540 Class I 1
and 2 material and a preload of 70 percent of ultimate tensile strength j
for many of the Reactor Coolant System (RCS) anchor bolts for sup' ports and restraints. These materials have a minimum yield strength of 150 ksi and 140 ksi, respectively. Recently, it has been documented that stress corrosion cracking (SCC) is a potential failure mode for high yield strength (>120 ksi) low alley steel bolt:ng material subjectr I to appreciable steady state loads (generall t 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. D-3871 OI 0045-18 dated August 19, 1981) that they had reported to the NRC, under the l
requirements of 10 CFR Part 21, concerns that B&W has with regard to stress corrosion cracking of high strength bolting material.
Interim Progress Through participation with the Atomic Industrial Forum (AIF) Subcommittee on Materials Requirements, TVA is evaluating the potential safety implications involved with the subject deficiency. TVA understands that the NRC is aware that this is an industry-wide concern and that they are addressing this concern through the issuance of draft NUREG-0577
" Potential fer Low Fracture Toughness and Lamellar Tearing on PWR Steam l
Generator and Reactor Coolant Pump Supports."
If it is determined that there is a significant safety issue associated with this deficiency, TVA will report this to the NRC as required by 10 CFR 50.55(e) for~all affected TVA Plants.
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