ML20247C608
| ML20247C608 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 05/15/1989 |
| From: | Robert Williams PUBLIC SERVICE CO. OF COLORADO |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-88-010, IEB-88-10, P-89178, NUDOCS 8905240530 | |
| Download: ML20247C608 (3) | |
Text
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h Public Service' Company of Colorado P.O. Box 840 Denver, CO 00201- 0040 May 15, 1989 R.O. WILLIAMS, J R.
Fort St. Vrain SENIOR VICE PRESIDENT Unit No. 1 NUCLEAR OPERATIONS P-89178 U. S. Nuclear Regulatory Commission ATTN:
Document Control Desk Washington D. C. 20555 Docket No. 50-267
SUBJECT:
PSC Test Results of NRC Bulletin 88-10,
" Nonconforming Molded-Case Circuit Breakers"
REFERENCE:
- 1. PSC Letter, Williams to Document Control Desk, Dated March 31, 1989 (P-89104)
- 2. NRC Letter, Callan to Williams, dated January 13, 1989 (G-89021)
Dear Sirs:
In response to NRC Bulletin 88-10, the testing of molded-cast-( ' cuit breakers (CBs) not traceable to the ci rcui t-brea ker manufacturers (CBM) was completed on April 3, 1989.
PSC Response to Bulletin 88-10, P-89104 (Reference 1),
explained that no testing of circuit breakers is required by NRCB 88-10.
Altbough nrt required, 27 CBs out of safety-related stock, purchased between January 1983 and August 1988, were successfully tested per Attachment A of NRCB 88-10.
In addition to this testing, another four CBs were tested.
The 1
documentation on these four CBs was considered questionable with 1
respect to NRC Bulletin 88-10. The four CBs were of the same stock code and were procured on purchase order N-6551 for spare stock.
I None of the four CBs purchased on this purchase order have ever been installed. Three of the four CBs successfully passed all tests.
The l
test results of the fourth CB were inconsistent.
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. P-89178 May 15, 1989 While performing the instantaneous trip test on the fourth CB, the trip values'of one pole was inconsistent with the other two poles.
The one -pole. tripped at twice the current value and three times the trip time of the other two poles.
The test was. repeated and a different-pole tripped in the same manner. After.the CB had time to cool down, the test was performed a third time. The trip time of two poles was twice the time of the third pole. All current values for all tests were within the limits of the manufacturer's test curves.
Since all three poles of the CB didn't trip in a similar fashion, and the tripping of the CB was inconsistent, the CB was removed from safety-related stock.
The ITE EF3-8080 CB was purchased from a. local. distributor, Denver Distributors, Inc., a non Part 21 supplir.r The CB was purchased in October 1985 on Purchase Order N-6551.
The CB was inspected per the guidelines provided by a NUMARC letter, dated March 8,
1989.
In acc.ordance with these_ guidelines, we do not believe the CB to be refurbished. 51oce test values were within the curve limits, the inconsistency of this CB would not constitute a Part 21,.
nonconformance.
In response to NRC letter, G-89021 (Reference 2), the CB has been set aside and will be retained for a period of six months.
Very truly yours, j R. O. Williams, Dr.
Sr. Vice President Nuclear Operations R0W/KLB/RRD/km cc:
Regional Administrator, Region IV, ATTN: Mr. T. F. Westerman, Chief Projects Section B Mr. Robert Farrell Senior Resident Inspector Fort St. Vrain
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1 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION l
In the Matter
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Public-Service Company of Colorado
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Docket No. 50-267 Fort St. Vrain Unit No. 1
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' AFFIDAVIT I
R.
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Williams, Jr.
being first duly sworn, deposes and says:
That he is Senior Vice President, Nuclear Operations, of Public Service Company 'of Colorado, the Licensee herein, that he has read thelinformation presented in the attached letter and knows the contents thereof, 'and that the statements and matters set forth therein are true and correct to the best of his knowledge, information and belief.
R. O. Williams, Dr.
Senior Vice President Nuclear Operations STATEOF-ONA24
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COUNTY OF Oc,1,sA
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Subscribe and sworn to before me, a Notary Public on this
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day of
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- from, Notary Public My commission expires Co m,v y
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