ML20085L779
| ML20085L779 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 03/04/1975 |
| From: | Brey H PUBLIC SERVICE CO. OF COLORADO |
| To: | Howard E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| Shared Package | |
| ML20085L781 | List: |
| References | |
| RO-50-267-75-1A, NUDOCS 8311020446 | |
| Download: ML20085L779 (4) | |
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o P. O. Box 361, Platteville, Colorado 80651 March 4, 1975 t
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Mr. E. Morris Howard, Director l~ l.1 arf 15797.
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Office of Inspection & Enforcement 611 Ryan Plaza Drive
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Suite 1000
/G Arlington, Texas 76012 REF: Facility Operating License No. DPR-34 Dechet U0. 50 257
Dear Mr. Howard:
Enclosed please find a copy of Unusual Event Report No. 50-267/75/1-A, Final, submitted per the requirements of the Technical Specifications.
Very truly yours,
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H. Larry Brey Superintendent-Operations Fort St. Vrain Nuclear Generating Station HLB:il ec:
Mr. Angelo Giambusso k
2854 750304 102 f03OOO S
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REPORT DATE: February 26, 1975 UNUSUAL EVENT OCCUPJtENCE DATE: Jancary 17, lo75_
FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE COMPNW OF COLORADO P. O. BOX 361 PLATTEVILLE, COLORADO 80651 REPORT NO. 50-267/75/1-A
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FINAL IDENTIFICATION OF OCCURRENCE:
An e3cetrical inspection of the main control board and auxiliary electrical equipment room revealed discrepancies in maintaining loop and bus segregdtion requirenents according to Specification 1-N-2, Supplement.
The segregation violations are the accumulated results of modifications and revisions to the essential circuits since the initial audit involving single failure criteria.
CONDITIONS PRIOR TO OCCliRFD'CE:
Steady State Power Routine Siv2tdovn Hot Shutdown Routine Load Change X
Cold Shutdown Other (Specify)
Refueling Shutdown Routine Startup The major plant parameters at the time of the event were as follows:
Power RTR 0
MWth Elect.
O MWe Secondary Coolant Pressure O
psig Temperature 0
- F Flow 0
- /hr.
Primary Coolant Pressure O
psig Temperature N100
- F Core Inlet.
4100
- F Core Outlet Flow 0
- /hr.-
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DES 5RIPTIO'NOF OCCUltitENCE:
Some of the colored insulated ulres used in the electrical installation
'i work. to denote.non-interruptible Bus 1 and Eus 2 circuits and also some of the hand switches and relays used in essential circuits were not separated by the minimun distance to maintain segregation requirements.
APPARENT CAUSE OF OCCURRENCE:
Design Unusual Service Cond.
Including Environ.
Manufacture Component Failure X
-Installation /Const._
Other (specify)
Operator
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Procedure ANALYSIS OF OCCURRENCE:
Wiring and schematic diagrams and the work sheets used during an original
-electrical audit were revicued to ensure that any modifications or revisions to essential circuits did not violate segregation requirements.
All dis-crepancies found were referred to the general contractor for review and correction.
CORRECTIVE i
_ ACTION:
j Allcoloredinsulatedwiresusedinessentialcirbuitsthatdonotmeet.
segregation requirements have been zipper tubed or changed to high temperature insulated uires.
Hand suitches and relays used :ba essential circuits that do -
not meet segregation requirements have been separated by asbestos barrier boards-on February 11, 1975.
An inspection was performed by Public Service CompanyLto ensure chat all electrical installation work. is correct land meets segregation criteria.
FAILURE DATA /
_SIMILIAR REPORTED OCCURRENCES:
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i jo;aes Reader APPROVED:hederic E1.:f1 93
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. Sw:trt Site Engineer Superintendent, Production Fort St. Vrain Nuclear Fort St. Vrain Nuclear Cencrating Station Cencrating Station
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