ML20071D714

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Final Deficiency Rept Re Safety Injection Tanks - safe-end Indications.All Linear Indications in safe-end-to-nozzle- Welds in Safety Injection Tanks 3 & 4 Removed & Rewelded Per ASME Section XI Plan.Final Radiographs Verified Repairs
ML20071D714
Person / Time
Site: Satsop
Issue date: 03/02/1983
From: Leddick R
WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
Shared Package
ML20071D684 List:
References
10CFR-050.55E, 10CFR-50.55E, GO3-83-186, NUDOCS 8303110306
Download: ML20071D714 (1)


Text

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Washington Public Power Supply System Box 1223 Elma. Washington 98541 (206)482-4428 Docket No. 50-508 3

March 2, 1983 G03-83-186 , u.

U. S. Nuclear Regulatory Commission, Region V Office of Inspection and Enforcement 1450 Maria Lane, Suite 260 Walnut Creek, California 94596-5368 Attention: Mr. D. M. Sternberg, Chief Reactor Projects Branch No. 1

Subject:

POTENTIAL 10CFR50.55(e) DEFICIENCY SAFETY INJECTION TANKS SAFE-END INDICATIONS (D/N #23)

References:

1) Letter, G03-82-564, Mr. R. S. Leddick to Mr. T. W. Bishop, PT Indications-Screty Injection Tanks and Reactor Pump Supports (D/N #23), dated June 4, 1982.

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2) NRC Letter, Mr. T. W. Bishop to Mr. R. S. Leddick, Potential 10CFR50.55(e) Deficiency-RT Indications, Safety Injection Tanks and Reactor Pump Supports, dated June 22, 1982.

The final report for questionable indications on radiographic film for WNP-3 Safety Injection Tanks, Reactor Coolant Pump Volutes and Reactor Coolant Pump Motor Supports was forwarded to your office by Refereice 1). The report noted that, with the exception of the linear indications in the Safety Injec-tion Tank safe-ends, the identified deficiencies were not reportable per 10CFR50.55(e). Reportability of the safe-end indications would be evaluated and addressed by Combustion Engineering (CE).

Upon NRC review of the final report, it was determined by your staff (see Reference 2) that reportability of the safe-end indications should be addressed by the Supply System. Accordingly, an evaluation of the safety implications has been completed. Attached is the Supply System approved final report for the subject deficiency. It has been concluded that the safe-end indications are reportable in accordance with the criteria of ,

10CFR50.55(e),

r303110306 830307 PDR ADOCK 05000508

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l Mr. D. M. Sternberg March 2,1983 Page 2 G03-83-186 1

Should you have any questions or desire further information, please contact me directly.

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R. S. Leddick (760)

Program Director, WNP-3 DRC:nj ,

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. .. Attachment to: Letter No. G03-83-186, dated March 2, 1933 WASHINGTON NUCLEAR PROJECT NO. 3 10CFR50.55(e) DEFICIENCY SAFETY INJECTION TANKS SAFE-END INDICATIONS (D/N #23)

. Description of the Deficiency '*

Linear defects were detected in radiographs, taken after Post Neld Heat Treatment (PWHT), of safe-end-to-nozzle-welds for Safety Injec-tion Tank Nos. 3 and 4. These indications did not appear in the radi ographs taken prior to PWHT. As a result, it was concluded that the linear defects may hive resulted from or propagated during

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ri.HT.

During repair, extensive grinding was required to remove the defects.

The grinding encompassed most of the weld circumference with a depth generally exceeding one inch and a width of approximately one inch.

Analysis of Safety implications The linear defects in the safe-end-to-nozzle-welds, if left uncorrected, could adversely affect the safety of operations of the plant. Conse-quently, the deficiency is reportable in accordance with the criteria of 10CFR50.55(e).

The above conclusion is based on postulating loss of tank function as a result of partial or complete pipe severance at the welded joint.

This loss of tank function would violate the assumptions utilized in analyzing large break LOCAs. Specifically, Section 6.3.3.2.2 of the CESSAR-F states:

Four safety injection tanks (SITS) are piped so that each SIT feeds a single cold leg injection point. Thus:

a. For a break in the pump discharge leg, the safety injection flow credited is 100% flow from three SITS since it is assumed that all injection in the cold leg is spilled.
b. For breaks in other locations, the safety injection flow credited is 100% flow from four SITS.

Corrective Action Taken All linear indications, found in the safe-end-to-nozzle-welds of Safety Injection Tank Nos. 3 and 4, were removed and rewelded in accordance with the ASME Section XI plan submitted by CE and approved by the Supply System.

Removal of the indications was verified by PT and the final radiographs of the repair weld have been reviewed and accepted by the Supply System. >