ML20112A889
| ML20112A889 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 02/28/1985 |
| From: | Hufham J TENNESSEE VALLEY AUTHORITY |
| To: | Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| NCR-2857, NCR-2915, NUDOCS 8503180502 | |
| Download: ML20112A889 (2) | |
Text
TENNESSEE VALLEY AUTHORITY W dhe"s% $ $ R r"e"e W e?uer M
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BLRD-50-43844-f93 NM 0 BLRD-50-43944 -18 l
U.S. Nuclear Regulatory Ccxnmission l
Region II Attn:
Dr. J. Nelson Grace, Regioml Administrator tlanta eorgia 35 32 l
Dear Dr. Grace:
l BELLEUQiTE NUCLEAR PLANT UNITS 1 AND 2 - DEFECTS IN REACTOR PRESSURE VESSEL STUD BOLT HOLES - BLRD-50-43844-19, BLRD-50-43944 REVISED FINAL REPORT FOR UNIT 1 AND FINAL REPORT FOR UNIT 2 The subject deficiency was initially reported for unit 1 to NRO-0IE Inspector P. E. Fredrickson on February 16, 1984 in accordance with 10 CFR 50.55(e) as NCR 2857.
NCR 2915 was subsequently identified whidi documented the deficiency for unit 2.
This was followed by our interim reports dated March 14 and July 13, 1984.
Our fiml report for unit 1 and our third interim report for unit 2 was autxnitted October 30, 1984.
Enclosed is our revised final report for unit 1 and final report for unit 2.
TVA no longer considers these conditions to be adverse to the safety of plant operations. Therefore, we will amend our records to delete NCRs 2857 and 2915 as 10 TR 50.55(e) itens.
If you have any questions, please get in touch with R. H. Shell at FTS 858-2688.
Very truly yours, TENNESSEE VALLEY AUIHORITY f-J. W. Hufham, Manager Licensing and Regulations Enclosure l
cc:
Mr. James Taylor, Director (Enclosure)
Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Records Center (Enc 1caure)
Institute of Nuclear Power Operations 1100 Circle 75 Parleaay, Suite 1500 Atlanta, Georgia 30339 8503180502 850228 DR g
ADOCK 05000439 g (
ggg PDR An Equal Oppertunity Employer OFFlOAL COPY
i EN1 Q5URE j
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t BELLEFOITE NUCLEAR PLANY gilts 1 AND 2 j
DEFECTS IN REACf 0R PESSURE VESSEL STUD BET HOLES BLRD-50-438/84-19, BLRD-50-439/84-18 i
NCRs 2857 AND 2915 10 TR 50.55(e)
REVISED FINAL EPORT FOR UNIT 1 AND FINAL FOR UNIT 2
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i Description of Deficiency 4
i It was identified that 56 of the 60 unit 1 reactor pressure vessel (RPV) stud bolt holes have damaged, corrosion pitted, tool chattered, stained and rough
, i threads. Five of the stud holes were rejectable when checked with the j
vendor-supplied no-go gauge (used for checking dimensional configuration of the threads). This was doctanented on Nonconformance Report (NCR) 2857.
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This condition has subsequently been identified as applicable to unit 2 in j
that 57 of the 60 unit 2 stud holes have similar corrosion damaged, tool chattered and rowgh threads. Of the 58 stud holes gauged, six were rejectable when checked with go and no-go gauges. Two of the RPV. stud holes were rot checked due to the insertion of alignment studs. This condition for j
l unit 2 has been documented on NCR 2915.
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l TVA has determined that the corrosion damage and staining is due to a lack of adequate preventive maintenanoe and inspections. Some of the damaged threads l
may be due to mishandling of the tenporary stud bolts during installation of l
, the RPV.
Pmventive maintenance was inadequate because the manufacturer's maintenance instructions were rot completely included on the maintenance i
inspection requirements sheet, attachment B of Bellefonte Nuclear Plant
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Quality Control Procedure (BW-QCP) 1.3 "Pmventive Maintenance."
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Safety Inclications IVA mquested a disposition of the subject deficiencies from the vendor,.
l Babcock and Wiloox (MW). Based on MW's inspection &ta and analysis (MW doctanent Nos. 51-1151007-00 and 32-1150598-00 for unit 1 and letters Nos.
j D5101 and D5294 for unit 2) MW has recommended dispositioning tho affected j
unit 1 and 2 HPV ' stud bolt holes to use-as-is. TVA has approved this
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disposition and has closed NCRs 2857 and 2915 and no longer considers 10 TR 50.55(e) to' be applicable to these items.
i To prevent recurrence of this deficiency, TVA will follow B&W's moommended 1
maintenanoe instructions and will elean sach affected atud bolt hole and i
apply an approved protective coating to each hole. Each stud bolt hole with a seal plug and 0-ring will be inspected every 6 months. Any evidence of moisture, rust, or bleeding of rust from existing pitted holes will require j
that the affected holes be cleaned, coated and resealed. Stud bolt holes not i
j having seal plugs installed will have a wooden cap installed and will be inspected every 2 months. The maintenance requirements sheet, attachment B of BW-QCP 1 3, for the RPV stud bolt holes has been revised to mflect these requi mment s..
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