ML20134G820
| ML20134G820 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 07/31/1985 |
| From: | Hufham J TENNESSEE VALLEY AUTHORITY |
| To: | Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| NUDOCS 8508280103 | |
| Download: ML20134G820 (2) | |
Text
.,
d TENNESSEE VALLEY AUTHORITY CH ATTANOOGA. TENNESSEE 374ot 1630 Chestnut Street Tower II 85 AUG 7 A8:I8 July 31, 1985
- BLRD-50-438/84 BLRD-50-439/84-45
~U.S. Nuclear Regulatory Commission Region II-
' Attn:
Dr.
J.~ Nelson Grace, Regional Administrator 101'Marietta Street, NW, suite 2900
- Atlanta, Georgia 30323
Dear Dr. Grace:
BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - INCORRECT BOLT STRESS ALLOWABLES USED
. IN FLANGE QUALIFICATION - BLRD-50-438/84-49 AND BLRD-50-439/84 SECOND INTERIM REPORT
- The subject deficiency was initially reported to NRC-OIE Inspector P. E. Fredrickson on September 7, 1984 in accordance with 10 CFR 50.55(e) as NCR BLN CEB 8414. Our first interim report was submitted on October 9, 1984.
i Since then a related nonconformance report (NCR) BLN CEB 8419 was issued. We
" intend.to report on both NCR's simultaneously.
Enclosed is our second interim report. We expect to submit our next report on or about November 4, 1985.
If you have any questions, please get in touch with R. H. Shell at FTS 858-2688.
Very truly yours, f
I TENNESSEE VALLEY. AUTHORITY dnt1A (J. W. Hufham, Manager r.
Licensing and Risk Protection l
[-
Enclosure L
cc:
Mr. James Taylor, Director (Enclosure)
[-
Office of Inspection and Enforcement i
U.S. Nuclear Regulatory Conunission Washington, D.C.
20555 Records Center (Enc'losure) i Institute of Nuclear Power Operations 1100 circle-75 Parkway, Suite 1500
. Atlanta, Georgia 30339 I
h 8508280103 850731 PDR ADOCK 05000438 S
PDR I k An Equal Opportunity Employer y
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ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 INCORRECT BOLT STRESS ALLOWABLES USED IN FLANGE QUALIFICATION BLRD-50-438/84-49, BLRD-50-439/84-45 10 CFR 50.55(e)
NCRs BLN CEB 8414 AND BLN CEB 8419 SECOND INTERIM REPORT Description of Deficiency Nonconformance report (NCR) BLN CEB 8414 (CDRs BLRD-50-438/84-49, BLRD 439/84-45) documented a problem with piping flanges analyzed in, problem N4-1KE-0 that were qualified using incorrect bolt allowables. The differences between the stress values used and the correct allowables are significant and 2
range as high as 10,000 lb/in. The analysis was based on preliminary infbrmation which was not verified by the subsequent controllng documentation (i.e., the bill of material). The bill of material did not specify high-strength bolts. This problem is potentially applicable to other Bellefonte Nuclear Plant (BLN) piping analysis problems but is not applicable to other TVA plants.
Subsequent to the first report on NCR BLN CEB 8414, a related NCR, BLN CEB 8419, was issued. This NCR pertains to incorrect assumptions made by the rigorous piping stress analyst as to the strength of flange bolting material.
Some examples are:
(1) flange bolts for orifice flange element IFE-957-A on mechanical drawing 1BWO453-KE-12 are not specified, yet the analyst assumed high-strength bolts.
(2) Bill of material 3BM0416-N5-00 sheet 5 calls for ASTM SA193 grade B7, B8, or equal bolts. The allowables for these bolts are not equal and the analyst assumed the higher strength bolts were used.
(3)
The flange bolt material on bill of material 3BM0453-KE-05 sheet 8 is to be SA193 grade B7. This differs from SA307 which is specified on NAVC0 drawing 15-86, contract No. 75K35-86162. The bolt material allowables differ by 18,000 lb/in2 The analysis, which used the erroneous assumptions, is not t
necessarily conservative.
Interim Progress TVA has completed the piping analysis review required to scope the problem.
documented on NCR BLN CEB 8414. No reanalysis of problem N4-1KE-0 was required and the affected bills of material have been revised to specify high-strength bolts.
TVA is pursuing the disposition of NCR BLN CEB 8419. Further infbemation will be provided when the appropriate corrective actions and actions required to prevent recurrence have been established.
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