ML20085L639

RO 50-267/75/6:on 750402,bearing Water Makeup Pump P-2105 Handswitch Insp Revealed Discrepancies in Maintaining Bus Segregation Requirements.Cause Not Stated.Field Change Notice Issued to Correct Discrepancies

ML20085L639
Person / Time
Site:	Fort Saint Vrain
Issue date:	04/30/1975
From:	Brey H PUBLIC SERVICE CO. OF COLORADO
To:	Howard E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
RO-50-267-75-6, NUDOCS 8311020181
Download: ML20085L639 (3)

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!. Pul>1ie Service Comisisw & Cdemf3 .

P. O. Box 361, Platteville, Colorado 80651

v. N April 30, 1975 Mr. E. Morris Howard, Director Nuclear Regulatory Commission .

Region IV Office of Inspection & Enforcement

, .- 611 Ryan Plaza Drive

, Suite 1000 -

Arlington, Texas 76012 I

Dear Mr. Howard:

l REF: Facility OperatinF License No. DPR-34 Docket No. 50-267 i- Enclosed please find a copy of Unusual Event Report No. 50 7/75/6, l final, submitted per the ' requirements of the Technical Specif3 itions.

Very truly yours, .

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g. agmp up t

i s. H. Larry Brey -i l

Superintendent.-Ope ra tions Fort St. Vra'in Nuclear Generating Station HLB:11

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cc: Mr. Angelo Ginobusso ,

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REPORT DATE: April 22, 1975 i. '. ~ ~.iAL EVENT DCCURRENCE DATE: April 2, 1975 i

FORT ST. VRAIN NUCLEAF.CENERATING STATION PUBLIC SERVICE COMPANY OF COLORADO

, P. O. BOX 361 PLATTEVILLE, COLORADO 80651

, REPORT NO. 50-267/75/6 Final IDENTIFICATION OF OCCURRENCE:

An electri:a1 inspection by Stearns-Roger and General Atomic Company on the handswitches for P-2105 (HS's 21331 A, B, and C)/ revealed discrepancies

• in maintaining bus segregation requirements in accordance with Specification 1-N-2,Supplemenq/ The segregation violations are the result of a modification to the control circuit for the Bearing Water Makeup Pump (P-2105).

This is identified as an Unusual Event, per Technical Specification definition AC 7.6.c.3.

CONDITIONS PRIOR -

TO OCCURRENCE: Steady State Power Routine Shutdown Hot Shutdown F.outine Loa'd Change I Cold Shutdown. Other (specify)

Refueling Shutdown-Routine Startup The major plant parameters at the time of the event were as follows:

Power -

Rtr. O MWth Elect. 0 MWe

' Secondary Coolant Pressure 1500 psig Temperature 200 *y Flow. ~150,000 #/hr. -

Primary Coolant Pressure 130 psig -

. ' Temperature 206 *F Core Inlet 206 *F Core outlet Flow- Less than 100.000- ' f /hr. - '

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. , . ~ , , N "c;h 2 DESCRIPTION OF OCCURRENCE:

The control circuitry for the Bearing Water Makeup Pump (P-2105) was redesigned in May, 1973, to provide alternate power sources to P-2105.

The original design allowed P-2105 to be supplied fron bus 2 only, which was not sufficient for conditions where house power was being supplied by the emergency diesels. The new design added Bus 1 and Bus 3 capability.

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APPARENT.CAUSE OF OCCURRENCE: Design Unusual Service Cond.

Including Environ.

Manufacture Component Failure ,

Installation /Const. Other (specify)

Operator Procedure ANALYSIS OF OCCURRENCE: .

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The new circuits were not installed in accordance with Specification 1-N-2, Supplement. The wiring Qgj Bus 2 was installed using Bus 1 ,

routing and wires leading to the three handswitches did not meet minimum c1'earance requirements. The wires leading to the. control relays

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did not adhere'to segregation criteria.

CORRECTIVE ACTION:

General Atomic Company wrote a Field Change Notice (FCN) to correct all discrepancies in the Bearing Water Makeup Pump control circuitry. All colored insulated wires that did not meet segregation criteria were zipper tubed or changed to high temperature insulated wires. A Stearns-Roger Quality Control audit was completed on the new wiring and all discrepancies were cleared. The control wiring presently meets all, segregation requirements as set forth in Specification 1-N-2, supplement.

FAILURE DATA /ffIMILAR REPORTED OCCURRENCES: ,

Report No. 50-267/75/1-A, dated Fe'.fuiry 26, 1975. -

PROGRAMMATIC IMPACT:

-s None CODE TMPACT:

9 None k' .

Reconsnended: Approved: // -

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H. Larry Brdy rederic.E. Swart

' Superintendent-Operatihns ' Supt. Nuclear Production I Fort St. Vrain Nuclear ' Public ' Service 'Co. 'of l

.- Generating Station ~ Colorado