ML20082E361

Interim Deficiency Rept 51 Re Reactor Coolant Pump Defect. Initially Reported on 830927.Cause Under Investigation. Existing Design Will Be Retested W/Addl Instrumentation. Final Rept Will Be Provided by 840601

ML20082E361
Person / Time
Site:	Satsop
Issue date:	10/31/1983
From:	Kohler A WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	Bishop T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
10CFR-050.55E, 10CFR-50.55E, 51, GO3-83-848, NUDOCS 8311280160
Download: ML20082E361 (3)

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Ikc Washington Public Power Supply System ,

Box 1223 Elma, Washington 98541 (206)482-4428 teg ll0'

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-2/g g October 31, 1983 G03-83-848 NEl0/iV7,tg U. S. Nuclear Regulatory Commission, Region V Office of Inspection and Enforcement 1450 Maria Lane, Suite 260 Walnut Creek, California 94596-5368 Attention: Mr. T. W. Bishop, Director Division of Resident Reactor Projects and Engineering Programs

Subject:

POTENTIAL 10CFR50.55(e) DEFICIENCY REACTOR COOLANT PUMP DEFICIENCIES D/N #51

.0n September 27, 1983, the Supply System notified your office of a poten-tial 10CFR50.55(e) deficiency concerning the subject condition. An investigation is in progress; however, sufficient data is not avai!able, at this time, to determine the cause. Attached is a Supply System approv-ed Interim Report that provides a description of the problem, analysis of safety significance and a proposed resolution.

It is anticipated that a final report will be provided to your office by June 1, 1984. Should you have any questions or desire further informa-tion, please contact me directly.

A. D. Kohler (760)

Program Director, WNP-3 DRC:nj Attachments cc: J. Adams - NESCO D. Smithpeter - BPA Ebasco - Elma -

5d- Sfi 8311280160 831031 PDR ADOCK 05000508 S PDR

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e Attachment to: Letter, G03-83-848, dated October 31, 1983 REACTOR COOLANT PUMP DEFECTS DEVIATION / NONCOMPLIANCE NO. 51 INTERIM REPORT DESCRIPTION OF DEFICIENCY Combustion Engineering reported problems encountered with regard to System 80 Reactor Coolant Pumps which had undergone hot functional testing at the ANPP No. 1 Project (Palo Verde). Inspections of the pumps revealed broken impeller vanes, minor erosion of diffuser vanes, broken or loose suction piping bolting, and some broken cap screws which held the diffuser halves together. Additionally, it is thought that because of pump induced vibrations, failures occurred in other loop equipment such as RDT thermowells, safety injection nozzle thermal sleeves, and some of the internal CEA guide tube shrouds. Since WNP-3 utilizes the System 80 in its design, it is assumed that similar failures could occur unless corrective measures are taken. All of the equipment for Unit 3 and some for Unit 5 has been received at the site and accepted.

ANALYSIS OF SAFETY SIGNIFICANCE The problem (s) with the reactor coolant pumps, if left uncorrected, could reasonably be postulated to adversely affect the safety of the pl ant. Therefore, the deficiency is considered reportable under the criteria of 10CFR50.55(e). This conclusion is based upon postulation of. broken pump parts, which would be expected to cause partial flow blockages within the core and/or possibly puncture fuel rod cladding.

Such effects would likely violate assumptions associated with Departure from Nucleate Boiling Regime (DNBR) analyses in Chapter 15 of CESSAR-F, (see Appendix 15A, " Loss of Primary Coolant Flow Methodology Descrip-tion").

PROPOSED RESOLUTION CE has undertaken an evaluation and test program to determine the reasons for the failures. In support of this program, CE has requested and obtained the applicable WNP-3/5 project's equipment and has committed to replace the equipment by June 1984.

To resolve the problem, CE has outlined a three phase program as follows:

1) Retest existing design with additional instrumentation installed to collect base data.

2) Modify existing equipment to reflect design modifications as determin-ed by testing data.

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REACTOR COOLANT PUMP DEFECTS

- DEVIATION / NONCOMPLIANCE No. 51' INTERIM REPORT - Page 2 PROPOSED RESOL'UTION '(Continued)

3) Test the new modified equipment under plant operating conditions

.to verify adequacy of . design.

STATUS!0F RESOLUTION It is not known J

at this time when the retesting will be completed.

CE has estimated that testing could require up to 1,000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> in duration. Until the testing is complete and the next two phases of the resolution are completed, a final report cannot be i epared.

Since CE has committed to returning the equipment by June of 1984, it is anticipated.that a final report would'be complete by this date.

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