ML20076G465

Final Part 21 Rept Re Inadequate Structural Design of Concrete Walls Separating Pump Cells in Category 1 Svc Water & Circulating Water Pump House.Initially Reported on 830418. Design Mod Completed.Const Commenced

ML20076G465
Person / Time
Site:	Seabrook
Issue date:	08/08/1983
From:	Sarsten G UNITED ENGINEERS & CONSTRUCTORS, INC.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
References
REF-PT21-83-068-000 PT21-83-068-000, PT21-83-68, SBU:76652, NUDOCS 8308310319
Download: ML20076G465 (3)

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• & Cor%tructors inC. O L 5 DENvLH 30 South 17th Street tcm ton Post Office Box 8223 "," [# g ,

Philadelphia. PA 19101 ,,ttey,cHoc August 8. 1983 SBU: 76652 Ref: Letter to Director, Of fice of Inspection and Enf orcement dated June 17, 1983 from United Engineers 6 Cons t ructors Inc.

File: 9.1, DCC Director Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555

Dear Sir:

Subject : 10CFR21 Final Report on a Defect Related to Public Service Company of New Hampshire Seabrook Station - Units 1 and 2 This is to inform you of the corrective action taken for a defect related to the adequacy of the Service Water Pump House structure for the Seabrook Station. We are providing this 10CFR21 final report to assure that the Commission has been adequately informed.

Details of our report are attached.

Very t7uly your,s, i f e /'

/ .E arsten VicI President - Power GES/RLE:rmk Attachment copy: -Regional-- Directo r. ; ,

USNRC: Region 1-8308310319 830808 DR ADOCK 05000443 PDR T EL EPHONE 215 422-3000 Twx 710-670-1267 TELEX 63-4203 TELECOPIER 215 422-3049 f A Reytheon Company

FINAL REPORT August 8, 1983 NAME AND ADDRESS OF THE INDIVIDUAL OR INDIVIDUALS INFORMING THE COMMISSION:

G. E. Sarsten, Vice Presdient - Power United Engineers & Cons tructors Inc.

30 South 17th Street Philadelphia, PA 19101 IDENTIFICATION OF THE FACILITY, THE ACTIVITY, OR THE BASIC COMPONENT SUPPLIED FOR SUCH FACILITY OR SUCH ACTIVITY WITHIN THE UNITED STATES WHICH FAILS TO COMPLY OR CONTAINS A DEFECT:

1 Public Service Company of New Hampshire, Seabrook Station. Design of the Service Water and Circulating Water Pump House station.

IDENTIFICATION OF THE FIRM CONSTRUCTING THE FACILITY OR SUPPLYING THE BASIC COMPONENT WHICH FAILS TO COMPLY OR CONTAINS A DEFECT:

United Engineers & Constructors Inc.

NATURE OF THE DEFECT OR FAILURE TO COMPLY AND THE SAFETY HAZARD WHICH IS CREATED l OR COULD BE CREATED BY SUCH DEFECT OR FAILURE TO COMPLY:

A " defect" exists in the structural design of the concrete walls separat-ing pump cells in the Category I Service Water and Circulating Water Pump House. This " defect" is due to the f act that these concrete walls were not designed to withstand forces associated with dif ferences in water levels in adjacent cells when one of these cells is dewatered for mainten-ance (access to the travelling screens and pumps).

The forces associated with dif ferences in water levels of adjacent cells when one cell is dewatered for maintenance would cause overstress in the lower portions of the concrete walls. In the Service Water Pump House, during a surge caused by the trip of the circulating water pump, the dif ferential water pressure head can reach 61 feet. The overstress caused by such pressure could cause the lower parts of the concrete wall to experience extensive cracking with the possibility of some spalling on both

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sides oi these walls.

THE DATE ON WHICH THE INFORMATION OF SUCH DEFECT OF FAILURE TO COMPLY WAS OBTAINED:

April 18, 1983

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IN THE CASE OF A BASIC COMPONENT WHICil CONTAINS A DEFECT OR FAILS TO COMPLY, THE NUMBER AND LOCATION OF ALL SUCil COMPONENTS IN USE AT, SUPPLIED FOR, OR BEING SUPPLIED FOR ONE OR MORE FACILITIES OR ACTIVITIES SUBJECT TO THE REGULATIONS IN THIS PART: i This defect applies only to the Seabrook Station, Units 1 and 2.

4 THE CORRECTIVE ACTION WHICH HAS BEEN, IS BEING, OR WILL BE TAKEN: THE NAME OF

' THE . INDIVIDUAL OR ORGANIZATION RESPONSIBLE FOR THE ACTION: AND THE LENGTH OF TIME THAT HAS .BEEN OR WILL BE TAKEN TO COMPLETE THE ACTION:

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1 The analysis and design of the required structural modification for the Service Water Pump House have been completed. Drawings have

been prepared and released to the field for construction, which has

commenced.

. ANY ADVICE RELATED TO THE DEFECT OR FAILURE TO COMPLY ABOUT THE FACILITY, ACTIVITY OR BASIC COMPONENT THAT HAS BEEN, IS BEING, OR WILL BE GIVEN TO PURCHASERS OR LICENSEES:

1

, Public Service Company of New llampshire has reported the defect I

under the provisions of 10CFR50.55(c).

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