ML20133H647
| ML20133H647 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 07/26/1985 |
| From: | Opeka J, Sears C NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES |
| To: | Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| F0809A, F809A, SD-85, NUDOCS 8508090436 | |
| Download: ML20133H647 (2) | |
Text
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NORT1 MAST UTILITIES o.ner orrico.. seio n street. seriin. Connecticut
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P.O. BOX 270 HARTFORD CONNECTICUT 06141-0270 k
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(203) 665-5000 July 26,1985 Docket No. 50-423 o
F0309A Dr. Thomas E. Murley Regional Administrator U. S. Nuclear Regulatory Commission Region 1 631 Park Avenue King of Prussia, PA 19406
Reference:
(1) I&E Notice 85-45.
Dear Dr. Murley:
Millstone Nuclear Power Station, Unit No. 3 Reporting of Potential Significant Deficiencies in Accordance with 10CFR50.55(e):
Seismic Interaction Between the Flux Mapping System and Seal Table (SD-85)
In a July 26, 1985 telephone conversation between your Mr. H. F. VanKessel and our Mr. P. 3. Quinlan, Northeast Nuclear Energy Company (NNECO) reported a potential significant deficiency in the design of Millstone Unit No. 3 in accordance with 10CFR50.55(e). The potential significant deficiency involved the potential seismic interaction of the flux mapping system with the seal table / bottom mounted instrumentation, Reference 1.
The Millstone Unit No. 3 flux mapping equipment is Category 2 but is installed directly above the seal table which constitutes the pressure boundary between the guide tubes for the incore instrumentation and the reactor coolant system.
Failure of the equipment support during a seismic event could cause damage to the instrument tubing / scal table resulting in a small break LOCA. The flux mapping equipment has not been analyzed for structural integrity during an SSE event. This condition is currently under evaluation by both Stone & Webster Engineering Corporation and Westinghouse.
8508090436 850726 PDR ADOCK 05000423 S
'0A
'. - Until additional information is obtained, a final report cannot be provided. We will provide an update on this matter by September 12,1985.
Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY b.
.b J. F. Opeka Senior Vice President By: C. F. Sears Vice President cc:
Mr. 3. M. Taylor, Director Division of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D. C. 20555
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