ML20080D943
| ML20080D943 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 08/23/1983 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| REF-PT21-83 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8308300656 | |
| Download: ML20080D943 (2) | |
Text
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.v TENNESSEE VALLEY AUTHORITY
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M4 400 Chestnut Street Tower II g3 400pg August 23, 1983 4 g,,
BLRD-50-438/83-36 BLRD-50-439/83-32 U.S. Nuclear Regulatory Comission Region II Attn:
Mr. James P. O'Reilly, Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30303
Dear Mr. O'Reilly:
BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - MAXIMUM TEMPERATURE INSIDE CONTAINMENT PROVIDED BY BABCOCK & WILFOX - BLRD-50-438/83-36, BLRD-50-439/83 FINAL REPORT The subject deficiency was initially reported to NRC-0IE Inspector Linda Watson on May 13, 1983 in accordance with 10 CFR 50.55(e) as NCR BLN NEB B306. This was followed by our first interim report dated June 13,.983 Enclosed is our final report. We consider 10 CFR Part 21 applicable to this deficiency.
If you have any questions, please get in touch with R. H. Shell at FTS 858-2688.
Very truly yours, TENNESSEE VALLEY AUTHORITY DS h L. M. Mills, Manager Nuclear Licensing Enclosure cc:
Mr. Richard C. DeYoung, Director (Enclosure)
Office of Insp?ction and Enferce:.cnt U.S. Nuclear R';gulatory Comis? ion Washington, D.C.
20555 Pueords Center (Enclosure)
Institute of Nuclear Power Operations 1100 Circle 75 Parkway, Suite 1500 Atlanta, Georgia 30339 83C-8300656 830823 DR ADOCK 03000438 p\\*0, 4. Q PDR r
I6 N 1983-TVA 50m ANNIVERSARY 1\\
An Equal Opportunity Employer
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ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 l
MAXIMUM TEMPERATURE INSIDE CONTAINMENT PROVIDED BY BABCOCK AND WILCOX BLRD-50-438/83-36, BLRD-50-439/83-32 10 CFR 50.55(e)
NCR BLN NEB 8306 FINAL REPORT Descriotion of Deficienev.
In the description of nonconformance (NCR) BLNASB8301, " Qualification of Protective Coatings," (which is being reported on separately) changes to the environmental criteria inside containment as stated in the Bellefonte FSAR were noted. Upon evaluating this NCR TVA personnel found that one criteria, the maximum containment temperature of 2860F, was provided by Babcock and Wilcox (B&W), Lynchburg, Virginia, before 1977. This maximum temperature was induced by a postulated Loss of Coolant Accident (LOCA).
B&W's main steam line break (MSLB) calculations resulted in a 263 F temperature for containment based on the presence a saturated liquid-vapor mixture. However, in 1977, TVA questioned the fact that the LOCA induced temperature of 2860F would be the maximum temperature. Rudimentary hand calculations done by TVA engineers showed that because of the presence of super-heated steam curing a MSLB conainment tamparatures would reach approximately 3900F. In subsequent correspondence. written in 1978, B&W changed the maximum containment temperaturo to 4250F. At no time during this sequence did TVA design personnel identify this discrepancy as a nonconformance as required by Engineering tasign Quality Assurance Procedure, EN DES-QAP 1.5 as they censide"ed the temperature change to be part of the normal evolution of plant design.
Safety Implications If the use of 2860F as the eximum containment temperature had gone uncorrected, safety-related equipment (primarily alectrical) would not have been qualified for the higher MSLB t<;eperature. As such a MSLB could have caused various safety-related equipnent necessary for safe shutdown to fail because of the high temperatures.
Corrective Action A copy of this NCR was submitted to B&W and they have replied that the increased MSLB temperature was due to a change in regulatory requirements and not to any B&W error. While TVA disagrees with B&W's position, no further action is required with B&W as the MSLB temperature has been changed, documented, and is being used in the plant design (and has been used since 1978) and in equipment qualification.
To assure compliance with TVA procedures, TVA initiated a procedure training program on February 22, 1982, and all involved personnel have beer. trained in the requirements of identifying and documenting nonconformanaes.
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