ML20099L244
| ML20099L244 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 02/27/1985 |
| From: | Hufham J TENNESSEE VALLEY AUTHORITY |
| To: | Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| NCR-3492, NUDOCS 8503200534 | |
| Download: ML20099L244 (2) | |
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TENNESSEE VALLEY AUTHORITY CH ATTANOOGA, TENNESSEE 374ot 400 Chestnut Street Tower II February 27, 1985 BLRD-50-438/84-51 85 teR 6 A7: 40 BLRD-50-439/84 -47 U.S. Nuclear Regulatory Cmmission Region II Attn:
Dr. J. Nelson Grace, Regioml Achinistrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323
Dear Dr. Grace:
BELLEFWTE NUCLEAR PLANT WITS 1 AND 2 - MISINTERPRETATIm 0F SUPPORT SP ACING REQUIRE}ENTS - BLRD-50-438/84-51, BLRD-50-439/84 FINAL REPORT The subject deficiency was initially reported to NRC-0IE Inspector P. E. Fmdrickson m October 5,1984 in accordance with 10 TR 50.55(e) as NCR 3492.
The first interim report was subnitted November 5,1984.
Enclosed is our final mport.
If you have any questions, please get in touch with R. H. Shell at FTS 858-2688.
Very truly yours,
TENNESSEE VALLEY AUTHORITY J. W. Huf ham, Mana ger Licensing and Regulations Enclosure
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cc:
Mr. Richard C. DeYoung, Director (Enclosure)
Office of Inspection and Enforcement U.S. Ntolear Regulatory Cmmission Washington, D.C.
20555 Records Center (Enclosure)
Institute of Nuclear Power Operations 1100 circle 75 Parkway, Suite 1500 Atlanta, Georgia 30339 l$
0503200534 850227 FDR ADOCK 05000438 PDR OFFICIAt. COPY An Equal Opportunity Employer
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'NCLOSURE BELLEFCNTE NUCLEAR PLANT UNITS 1 AND 2 MISINTERPRETATION OF SUPPORT SP ACING REQUIREENTS BLRD-50-438/84-51, BLRD-50-439/84-47 NCR 3492 10 TR 50.55(e)
FINAL 3EPORT Description of Deficiency Seismic cable tray supports at Bellefonte Nuclear Plant (BLN) have been located and installed by measurement of the distance between the inside edges of the support brackets. The supports should have been located by measurement of the distance between the center lines of the support brackets.
BLN design criteria N4-50-D78 and various cable tray support drawings (X2 series) require a maximum of 8 feet of separation between supports.
Adilitionally, BLN FSAR Section 3.10.31 states that cable tray supports will be spaced at a " maximin of 8 feet on centers." This condition has resulted in a center line to center line dimension in excess of 8 feet in some cases.
TVA has determined that the cause of this deficiency was BLN mgineering's misinterpretation of the applicable design criteria as it applies to references to " clear span between supports." This misinterpretation resulted in the determination that the measurement was to be made between the inside edges of the support brackets, s.
Safety Inclications The subject deficiency, had it remained tmcorrected, could possibly have resulted in the overloading of individual cable tray supports and/or overstressing of some cable tray spins during a seismic event. This potentially could have led to failure of the affected supports and/or cable trays. Should this have happened, the safety of operations of the plant could have been adversely affected.
Corrective Action TVA has evaluated the subject nonconformance report (NCR) and determined that all cable tray supports placed to date that are spaced 8 feet maximta clear span between the inside edges of the support brackets are structurally adequate and may be used as built. NCR 3492 has been closed.
Future installations of cable tray supports will be installed in accordance with the requirements on civil drawings. Also, BLN quality control procedure (QCP) 3 7 has been revised to clarify the 8 feet spacing requirement. All applicable personnel have-been retrained to the new revision.
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