ML20141N625

Final Deficiency Rept CDR-83-00-10 Re Westinghouse 7300 Process Protection Sys Ntc Card Relays.Initially Reported on 830617.Modified Ntc Printed Circuit Card Installed as Solution to Mercury Wetted Relay Contact Bounce Problem

ML20141N625
Person / Time
Site:	Seabrook
Issue date:	03/05/1986
From:	Devincentis J PUBLIC SERVICE CO. OF NEW HAMPSHIRE
To:	Starostecki R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
CDR-83--10, CDR-83-00-10, SBN-958, NUDOCS 8603170407
Download: ML20141N625 (3)

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SEABROOK STATIOF Engineering Offlee

1671 Worcester toad Framingham. Massachusetts 01701 M Service W New @ (6171-a72-sloo March 5, 1986 .

New Hompshire Yonkee h SBN-958 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 Project and Resident Programs

References:

(a) Construction Permits CPPR-135 and CPPR-136. Docket.

Nos. 50-443 and 50-444 (b) Telecon of June 17, 1983 A. L. Legendre (YAEC) to E. Kelly (NRC, Region I)

(c) PSNM Letter SBN-526, dated July 1, 1983. J. DeVincentis to E. W. Starostecki (d) PSNH Letter SBN-606, dated January 4, 1984. J. DeVincentis to R. W. Starostecki

Subject:

Final 10CFR50.55(e) Report; Westinghouse 7300 Process Protection System NTC Card 8telays (CDR 83-00-10)

Dear Sir:

We previously reported (References (b) through (d)) a potential 10CFR50.55(o) item associated with contact bounce in mercury wetted relays in Westinghouse 7300 process control cabinets.

Westinghouse has enSincered a modified NTC printed circuit card as a permaner*. solution to the mercury wetted relay contact bounce problem. Known as a daughtse board, the modified card consists of two additional reed relays wired in parallel to the mercury wetted relays. The reed relays are mounted horizontally on a 1-inch by 3-1/2-inch daughter board which is bolted to the NTC card with three screws, lock washers and nuts. This modified NTC card will permit porlodic on-line testing of 8.no Delta T/TAVG protection channels, with no chango to existing procedures.

0603170407 060305 ADOC,K 05000443 PDR 0 PDR P O Bor 300 Sect >oA NH03874 . halophore(603)d74 9521 7

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United States Nuclear Regulatory Commission Attention: Mr. Richard W. Starostocki Page 2 During normal operation, the reed relay contact will be wired in parallel with the mercury wetted relay contacts on the printed circuit board. The majority of the RTD eignal will continue to pass through the mercury wetted relay contacts, since they have a lower resistance than the reed relay contacts. However, during a seismic event, if bounce is experienced on the mercury wetted relay contacts, the RTD signal will pass through the reed relay contacts and allow for acceptable operation of the affected temperature channels.

Structural and seismic analyses was periarmed on the NTC card with the proposed modifications to determine the potential impact due to addition of the reed relays. The results of the evaluation indicate that the card's past qualification (structural integrity) by test is still valid.

Thir, modification has been installed on all affected instrument channels for Seabrook Unit 1.

This is our final report on this item for Unit 1. We will inform you when the action is complete for Unit 2.

Very truly yours, e- ,

jn 4 John DeVincentis, Director Engineering and Licensing cct Atomic Safety and Licensing Board Service LLat Director, Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555 i

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Diane Curran Petcr J. Mathews, May:r Harmon & Weiss City Hall 20001 S. Street. N.W. Newburyport, MA 01950 Suite 430 Washington,'D.C. 20009 Calvin A. Canney City Manager Sherwln E. Turk Esq. City Hall Office of the Executive Legal Director 126 Daniel Street U.S. Nuclear Regulatory Commission Portsmouth, NH 03801 Washington, DC 20555 ,

Stephen E. Merrill Robert A. Backus. Esquire Attorney General 116.Lowe11-Street Dana Bisbee, Esquire F.O. Box 516 Assistant Attorney General Manchester, NM 03105 Of fice of the Attorney General 25 Capitol Street Philip Ahrens, Esquire Concord, NH 03301-6397 '

Assistant Attorney General Department of The Attorney General Mr. J. P. Nadeau ,

Statehouse Station #6 Selectmen's Office Augusta. ME 04333 10 Central Road

• ye, NH 03870 Mrs. Sandra Cavutis Designated Representative of Mr. Angle Machiros the Town of Kensington Chairman of the Board of Selectmen RFD 1 Town of Newbury East Eingstan, NH 03a27 Newbury, MA 01950 -

Jo Ann Shotwell, Esquire Mr. William S. Lord  :

Assistant Attorney General Board of Selectmen Environmental Protection Dureau Town Hall - Friend Street Department of the Attorney General Amesbury, MA 01913 One Ashburton Place, 19th Floor Boston, MA 02108 Senator Gordon J. Humphrey 1 Pillsbury Street Senator Cordon J. Humphrey Concord, NH 03301 U.S. Senate (ATTN Herb Boynton)

Washington, DC 20510 (ATTN Tom Durack) H. Joseph Flynn Office of General Counsel Diana P. Randall Federal Emergency Management Agency 70 Collins Street 500 C Street, SW Seabrook, NH 03874 Washington, DC 20412 [

Richard A. Hempe, Esq. Matthew T. Brock, Esq.

Hempo and McNicholas Shatnes, Madrigen & McEachern 35 Pleasant Street 25 Maplewood Avenue Concord, NH 03301 P.O. Box 360 Portsmouth, NH 03801 Donald K. Chick Town Manager Cary W. Holmes Esq. '

Town of'Mmeter Holmes & Ells l 10 Front Street 47 WLnnacunnet Road  ;

Exeter WH 03833 Hampton, NH 03841 Brentwood Board of Sele:tmen Ed Thomas i RFD Dalton Road FEMA Retr,lon 1 Brentwood, NH 03833 John W. McCornack PO & Courthouso Boston, MA 02109 1