ML20134H163

Interim Deficiency Rept (CDR 85-00-10) Re Emergency Feedwater Sys High Flow Isolation Logic seal-in.Initially Reported on 850724.Seal-in for High Flow Signal Will Be Provided So Interlock Stays in Place Until Manually Reset

ML20134H163
Person / Time
Site:	Seabrook
Issue date:	08/01/1985
From:	Johnson W PUBLIC SERVICE CO. OF NEW HAMPSHIRE
To:	Starostecki R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
(CDR-85--10), (CDR-85-00-10), SBN-852, NUDOCS 8508280301
Download: ML20134H163 (3)

Text

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l j ( Wendell P. Johnson Vice President

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Pubuc Service of New HampeNr0 SB - 85 T.F. 02.2.2 New Hampshire Yankee Division 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 July 24, 1985, W. N. Fadden and D. E. Groves (YNSD) to J. Grant (Region 1)

Subject:

Interim 10CFR50.55(e) Report; Emergency Feedwater System High Flow Isolation Logic Seal-In (CDR 85-00-10)

Dear Sir:

On July 24, 1985, we reported a 10CFR50.55(e) item to Region 1

[ Reference (b)]. The following information is provided under the reporting requirements of 10CFR50.55(e):

Description of Deficiency Emergency Feedwater (EFW) flow to a steam generator faulted by a Feedwater (FWLB) or Main Steam Line Break (MSLB) is isolated automatically with redundant isolation valves when high flow is detected. This is required to ensure flow to the intact steam generators, to limit the energy release to the containment and to conserve the water in the CST.

The isolation logic includes an interlock to block a ccncurrent high flow isolation of the nonfaulted steam generators, on a train basis, when a high l

flow condition exists. The final design does not seal-in the high flow j logic. The interlock will be removed automatically when the faulted steam generator's EFW isolation valves close and reduco flow below the high flow signal reset point. With the faulted steam generator isolated, the flow to l

the intact steam generators will increase above the high flow setpoint. This will result in the sequential isolation of emergency feedwater to all steam 8enerators.

Analysis of Safety Implications ,

The accident analysis for the FWLB and MSLB assumes that emergency feedwater flow to the intact steam generators is at design flow 1 minute after the event. A complete isolation and a 10 minute delay for operator action to open the isolation valves for the intact steam generators may result in steam generator dryout.

g82 301 850801 -

S OCK 05000443 hl PDR \

P.O. Box 300 Seabrook,NHO3874 Telephone (603)4/4-9521 yk er

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United States Nuclear Regulatory Commission

' Attention: Mr. Richard W. Starostecki Page 2

.The high flow signal seal-in was to be included in the design to prevent the sequential isolation of all steam generators. The seal-in was not included when producing the detailed design drawings. This is considered an isolated event.

Corrective Action We will correct this problem by providing a seal-in for the high flow signal so that the interlock will remain in place until manually reset from the Control Room. This will prevent closure of the remaining emergency feedwater isolation valves on the same power train. EFW will always be available to at least 2 steam generators. High flow isolation / logic seal-in will be alarmed. A final report will be submitted when the corrective action has been completed.

Very truly yours, ZW Wendell . Johnson Vice President ec: Atomic Safety and Licensing Board Service List Director, Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555 4

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• William S. Jordan, III Donald E. Chick Diane-Curran Town Manager Harmon, Weiss & Jordan Town of Exeter 20001 S. Street, N.W. 10 Front Street Suite 430 Exeter, NH 03833 Washington, D.C. 20009 Brentwood Board of Selectmen Robert' G. Perlis RED Dalton Road Office of the Executive Legal Director Brentwood, NH 03833 U.S. Nuclear Regulatory Commission Washington, DC 20555 Richard E. Sullivan, Mayor City Hall Robert A. Backus, Esquire Newburyport, MA 01950 116 Lowell Street P.O. Box 516 Calvin A. Canney Manchester, NH 03105 City Manager City Hall Philip Ahrens, Esquire 126 Daniel Street Assistant Attorney General Portsmouth, NH 03801 Augusta, ME 04333 Dana Bisbee, Esquire Mr. John B. Tanzer Assistant Attorney General Designated Representative of Office of the Attorney General the Town of Hampton 208 State House Annex 5 Morningside Drive Concord, NH 03301 Hampton, NH 03842 Anne Verge, Chairperson Roberta C. Pevear Board of Selec tmen Designated Representative of Town Hall the Toun of Hampton Falls South Hampton, NH 03827 Drinkwater Road Hampton Falls, NH 03844 Patrick J. McKeon Selectmen's Office Mrs. Sandra Gavutis 10 Central Road Designated Representative of Rye, NH 03870 the Town of Kensington RFD 1 Carole F. Kagan, Esquire East Kingston, NH 03827 Atomic Safety and Licensing Board Panel U.S. Nuclear Regulatory Commission Jo Ann Shotwell, Esquire Washington, DC 20555 Assistant Attorney General Environmental Protection Bureau Mr. Angi Machiros Department of the Attorney General Chairman of the Board of Selectmen One Ashburton Place, 19th Floor Town of Newbury Boston, MA 02108 Newbury, MA 01950 Senator Gordon J. Humphrey Town Manager's Office U.S. Senate Town Hall - Friend Street Washington, DC 20510 Amesbury, MA 01913 (ATTN: Tom Burack)

Senator Gordon J. Humphrey Diana P. Randall 1 Pillsbury Street 70 Collins Street Concord, NH 03301 Seabrook, NH 03874 (ATTN: Herb Boynton)