ML20093E817
| ML20093E817 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 09/19/1984 |
| From: | Counsil W NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES |
| To: | Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| F0583A, F583A, NUDOCS 8410120267 | |
| Download: ML20093E817 (2) | |
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General Offices
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(203) 665-5000 September 19, 1984 Docket No. 50-423 F0383A Dr. Thomas E. Murley Regional Administrator Region i U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406
Reference:
(1)
W. G. Counsit to T. E. Murley, F0570A, dated July 5,1984.
Dear Dr. Murley:
Millstone Nuclear Power Station, Unit No. 3 Reporting of Potential Significant Deficiencies in Design and Construction High Energy Line Breaks Outside Containment In a June 5,1984 telephone conversation between your Mr. T. Rebelowski and our Mr. R. R. '!!viano, Northeast Nuclear Energy Company (NNECO), reported a potential signihicant deficiency in the design and constructica cf Millstone Unit No. 3 as r quired by 10 CFR 50.55(e). The potential significant deficiency involved tv o potential safety issues. One of the issues, the number of Reactor <
Coolants Pumps which need to be operating in Mode 3, was determined not to be a significant deficiency for Millstone Unit No. 3 (see Reference (1)). 'the other potential safety issue, high energy line breaks outside of containment, required additional review and is the subject of this report.
The safety issue concerns the potential impact of superht.ated steam on the environmental qualification of equipment outside of containment following a high energy line break. Previous mass / energy release analysis performed for steamline breaks did not account for steam suoerheating as a result of the uncovering of steam generator tubes. Certain equipment outside of containment may not be qualified for a superheated steam environment.
The Westinghouse Owner's Group has recently developed a program to address this issue. Once the results of this program are available, we will review our plant specific environments to determine if a problem exists for Millstone Unit No.3.
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We 'will provide you with additional information regarding this issue as it becomes available.
Very truly yours,
. NORTHEAST NUCLEAR ENERGY COMPANY JO W. G.' Counsil Senior Vice President cc:
Mr. R. C. DeYoung, Director Division of Inspection and Enforcement U. S. Nuclear Regulatory Commission Phillips Building 7920 Norfolk Avenue Bethesda, MD 20014 l
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