ML20127F477
| ML20127F477 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 04/30/1985 |
| From: | Counsil W, Opeka J NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES |
| To: | Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| F0716A, F716A, SD-73, NUDOCS 8505200463 | |
| Download: ML20127F477 (2) | |
Text
e General Offices a Selden Street Berlin, Connecticut j
P.O. BOX 270
.aos.mm eoma co.,,
HARTFORD CONNECTICUT 06141-0270 aan ase urura is cow.-
(203) 666-6911 g
April 30,1985 Docket No. 50-423 F0716A Dr. Thomas E. Murley Regional Administrator U.S. Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, PA 19406
Reference:
1.
W. G. Counsil letter to T. E. Murley, F0680A, dated March 1, 1985.
Dear Dr. Murley:
Millstone Nuclear Power Station, Unit No. 3 Reporting of Potential Significant Deficiencies in Accordance with 10CFR50.55(e):
Emergency Generator Load Sequencers (SD-73)
In a January 3,1985 telephone conversation between your Mr. T. Rebelowski and our Mr. G. M. Olsen, Northeast Nuclear Energy Company reported a potential significant deficiency in the construction of Millstone Unit No. 3 in accordance with 10CFR50.55(e). The potential significant deficiency involved emergency generator load sequencers supplied by Vitro Laboratories.
During start-up testing of the Millstone Unit No. 3 emergency generator load sequencers, it was determined that certain loads were not shed as required when the diesel generator breaker was opened during sequencing in certain operational modes. Specifically, the diesel generator breaker status inputs for the following loads were omitted:
o The quench spray pump, safety injection pump and residual heat removal pump on a Containment Depressurization Actuation (CDA) signal concurrent with a Loss of Power (LOP).
o The safety injection pump and residual heat removal pump on a Safety Injection Signal (SIS) concurrent with a LOP.
Subsequently, this was determined to be a significant deficiency for Millstone Unit No. 3 (Reference 1).
Vitro Laboratories provided a design modification package to correct this significant deficiency which was reviewed and approved by our engineering staff.
8505200463 850430 PDR ADOCK 05000423 S
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, iThis inodification was incorporated into the sequencers and successfully tested at Millstone Unit No. 3.
We consider this to lbe our final report for SD-73. We trust that the above information satisfactorily responds to your concerns.
Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY lA), b-W. G. Counsil Senior Vice President
%= Cs BY: 3. FM)1 eka L
f Vice President cc Mr. 3. M. Taylor, Director Division of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D. C. 20555 l
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