ML20023D306
| ML20023D306 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 05/16/1983 |
| From: | Devincentis J PUBLIC SERVICE CO. OF NEW HAMPSHIRE, YANKEE ATOMIC ELECTRIC CO. |
| To: | Starostecki R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, SBN-508, NUDOCS 8305200353 | |
| Download: ML20023D306 (3) | |
Text
1671 Worcester Rood Mah. ****chae"* 01701 Pubic Service of New Hampshire (6178-872 8100 May 16, 1983 S BN-508 T.F. Q2.2.2 United States Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, PA 19406 Attention:
Mr. Richard W. Starostecki, Director Division of Resident and Project Inspection
References:
(a) Construction Permits CPPR-135 and CPPR-136, Docket Nos. 50-443 and 50-444 (b) Telecon on April 22, 1983, A. L. Legendre (YAEC) to Jim Wiggins (NRC Region I)
Subject:
Final 10CFR50.55(e) Report; DS-416 Reactor Trip Switchgear
Dear Sir:
On April 22, 1983, a reportable 10CFR50.55(e) item was reported
[ Reference (b)] regarding the DS-416 Reactor Trip Switchgear.
The following information is provided per 10CFR50.55(e) and is considered to be the final report on this item.
Description of Deficiency A Westinghouse plant in startup testing experienced a DS-416 reactor trip l
breaker malfunction.
The malfunction was a result of deviations from breaker internal recommended clearances. Westinghouse evaluation has concluded that deviations from the recommended clearances could increase the potential for misoperation of the attachment, thereby creating a condition wherein the reactor trip switchgear might not open on automatic demand from the reactor protection system.
On April 15, 1983, Westinghouse informed operating plants of an additional DS-416 undervoltage attachment misoperation.
Investigation of this event revealed a missing retaining ring on one of the two undervoltage I
attachment pivot shafts.
This allowed the pivot shaft to move laterally such
[
that one end came out of its guide hole in the frame of the undervoltage attachment and did not permit the attachment to operate on demand. A missing j
retaining ring was also identified at another plant.
No misoperation of that l
attachment had been reported.
A R305200353 830516 er PDR ADOCK 05000443 4'
S PDR
/
1U00 Elm St.. P.O. Box 330. Manchester. NH O3105 + Telephone (603) 669-4000 TWX 7102207595
United States Nuclear Regulatory Commission May 16, 1983 Attention:
Mr. Richard W. Starostecki Page 2 l
The Westinghouse evaluation of the retaining ring issue revealed a discrepancy in design.
The groove in the shaf t receiving the retaining ring I
was not increased in width to be consistent with an earlier (1972) retaining ring design change.
The new retaining ring is wider than the original design and does not seat properly in the existing grooves.
This discrepancy increases the potential for misoperation of the DS-416 undervoltage attachment.
4 Analysis of Safety Implications Misoperation of the DS-416 undervoltage attachment creates a condition wherein the reactor trip switchgear might not open on automatic demand from the reactor protection system.
Corrective Action (1) Westinghouse has committed to replace the undervoltage attachments on DS-416 reactor trip switchgear supplied by Westinghouse for its Nuclear Steam Supply Systems.
(2) The new attachments have modified (widened) grooves to accommodate the new retaining rings.
(3) Manufacturing drawings have been revised and quality control procedures modified to assure that critical design dimensions are maintained during l
manufacture.
(4)
Furthermore, Westinghouse is developing and will implement a procedure for installation of the new attachments on DS-416 reactor trip switchgear i
in the plant.
This field installation procedure will provide for proper
-alignment and interface of the attachment with the breaker trip shaf t.
I l
Very truly yours, YANKEE ATOMIC ELECTRIC COMPANY l
AdA
/
{
J. DeVincentis
{
Project Manager MH0/dsm cc: Atomic Safety and Licensing Board Service List i
Director, Office of Inspection and Enforcement Wa shing ton, DC 20555
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ASLB SERVICE LIST Roberta C. Pevear Rep. Deverly Hollingworth Designated Representative of Coastal Chamber of Commerce the Town of Hampton Falls 209 Winnacunnet Road Drinkwater Road Hampton Falls, fH! 0304M Hampton, Nil 03042 Mrs. Sandra Gavutis Willi $mS. Jordan, III, Esquire Designated Representative of Harmon & Weiss the Town of Kensington 1725 I street, N.W.
RFD 1 Suite 506 East Kingston, NH 03827 Washington, DC 20006 Edward J. !!cDermott j Esquire E. Tupper Kinder, Esquire Sanders and McDermott Assistant Attorney General Professional Association Office of the Attorney General 408 Lafayette Road 208 State House Annex Hampton, NH 03842 Concord, NH 03301 Jo Ann Shotwell, Esquire Roy P.
Lessy, Jr., Esquire Assistant Attorney General Office of the Executive Legal Director Environmental Protection Bureau U.S. Nuclear Regulatory Commission Department of the Attorney General Washington, DC 20555 One Ashburton Place, 19th Floor Boston, MA 02108 Robert A. Backus, Esquire Ms. Olive L. Tash 116 Lowell Street Designated Representative of P.O. Box 516 Manchester, NH 0310'5' '
the Town of Brentwood R.F,D.
1, Dalton Road Brentwood, NH 03833 Philip Ahrens, Esquire Assistant Attorney General Edward F. Meany Department of the Attorney General Designated Representative of Augusta, ME 04333 the Town of Rye 155 Washington Road Rye, NH 03870 David L. Lewis Atomic Safety and Licensing Calvin A. Canney Board Panel City Manager U.S. N,uclear Regulatory Commission City Hall 126 Daniel Street Rm. EfF-439 Washington, DC 20555 Portsmouth, NH 03801 Mr. John B. Tanzer Designated Representative of the Town of Hampton 5 Morningside Drive Hampton, NH 03842