ML20044E703

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Determines Heinemann Electric Circuit Breaker Acceptable for Class 1E Applications at Unit 2.Conclusion Based on Tests at Natl Technical Sys Labs.Breakers Underwent Baseline Functional & Seismic Vibration Testing
ML20044E703
Person / Time
Site: Beaver Valley
Issue date: 05/17/1993
From: Sieber J
DUQUESNE LIGHT CO.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9305250335
Download: ML20044E703 (2)


Text

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g Beaver Valley Power Station -

SNppengport, PA 15077-0004 1

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~ JOHN D. SIEBER (412) 393 4 255~

I Senior Vice President and May 17,.1993 rai (412) s43-8068 Chief Nuclear Othcer Nocie<nt Power Dmsson U.

S.

Nuclear Regulatory Commission Attn:

Document Control Desk j

Washington, DC 20555

+

Subject:

Beaver Valley Power Station, Unit No. 2 Docket No. 50-412, License No. NPF-73 Heinemann Electric Co. Breakers Supplied by Systems i

Control Co.

Reference:

1)

NRC letter to DLC, dated December 5, 1991.

2)

DLC letter to NRC, dated January 3, 1992.

Reference 1

requested Duquesne Light Company to evaluate NRC Inspection Report No.

99900712/90-01 relative to the Heinemann.

circuit breakers supplied during the 1984-1986 time period by Systems Control Co.

for-use at our BVPS Unit 2 facility.

The inspection report concluded that Systems Control met the intent of the original-purchase specifications;

however, the vendor's Certificates of l

Conformance would not provide an adequate _ basis for 'use of the subject breakers in Class 1E applications without further evaluation and/or qualification testing.

Refererice 2

provided a

response to your letter of December 5,

1991, which summarized Duquesne Light company's evaluation-and justification for the breakers and committed to test a representative.

sample of the subject breakers.

l; The testing program was conducted at National Technical Systems (NTS) labs and the results have been reviewed by Duquesne Light company.

The Heinemann circuit breakers underwent a full receipt inspection prior to undergoing baseline functional testing in accordance with NTS/Acton Test Report

15891, Rev.

4 and NEMA AB-2/1984.

Following baseline functional testing, the equipment was I

subjected to multiple stages of testing, including thermal aging, mechanical

cycling, radiation
exposure, seismic
testing, and DBE harsh environment testing.

Baseline f" ~tional testing was performed-subsequent to each test stage to determine the equipments' l

acceptability.

All circuit breakers passed the functional testing following each test stage.

This demonstrated that the functional operation of_the breakers was acceptable.

240037 h

9305250335 930517 9

PDR ADOCK 05000412 a

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Beaver Valley Power Station, Unit No. 2 Docket No. 50-412, License No. NPF-73 Heinemann Electric Co. Breakers Supplied by Systems Control Co.

Page 2 During the seismic vibration

testing, anomalies were noted on certain DC series breakers that utilize an auxiliary 3rd pole switch.

The 3rd pole is a special Duquesne Light Company feature specifically designed to provide a supervisory function and that was is not associated with the protective function of the breakers.

The interpole linkage arm associated with the supervisory (auxiliary)

switch, or 3rd pole, failed to trip due to rubbing (friction / binding) following the seismic test.

The conclusion was that the circuit breakers would continue to operate properly and perform their safety function during and after a

seismic event;

however, a

lack of position indication could possibly be experienced.

To resolve this, Duquesne Light Company will institute administrative controls to procedurally verify breaker position locally following seismic events.

Post-seismic procedural changes will be implemented by September 30, 1993.

Based on the previously submitted justification and the results of the testing for the subject Heinemann circuit breakers, we have determined the subject circuit breakers acceptable for Class 1E applications at BVPS Unit 2.

If there are any questions concerning this response, please contact Mr. James V. Vassello at (412) 393-5203.

Sincerely, A

. Al_ LL~

D.

Sieber f

t-cc:

Mr.

L.

W.

Rossbach, Sr. Resident Inspector Mr.

T.

T.

Martin, NRC Region I Administrator Mr.

G.

E.

Edison, Project Manager Mr.

M.

L. Bowling (VEPCO)

.