ML20086B339
| ML20086B339 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 08/28/1974 |
| From: | Swart F PUBLIC SERVICE CO. OF COLORADO |
| To: | Howard E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| Shared Package | |
| ML20086B283 | List: |
| References | |
| AO-50-267-74-17, NUDOCS 8311170170 | |
| Download: ML20086B339 (4) | |
Text
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public Service Company *f Odlendo P. O, Box 361, Platteville, Colorado 80651
.- u... J August 28, 1974 Mr. E. Morris Howard, Director Directorate of Regulatory Operations Region IV USAEC 10395 West Colfax, Room 200 Denver, Colorado 80215 REF: Facility Operating License No. DPR-34 Docket No. 50-267
Dear Mr. Howard:
Enclosed please find a copy of Abnormal Occurrence Report, No. 50-267/74/17, submitted per the requirements of the Technical Specifications.
Very truly yours,
,M
-J Frederic E. Swart Superintendent Nuclear Production Fort St. Vrain Nuclear Generating Station FES:11
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Autuct 21, 1974 ABNORMAL
- OCCURRENCE FORTSN.VRAINKUCLEARGEMERATINGSTATION PUBLIC SERVICE COMPAhT OF COLORADO P. O. 30X 361 PLNfTEVILLE, COLORADO 80651 REPORT NO. 50-267/74/17 Preliminary IDEUTIFICATION OF GCCU!!".ENCE:
Phycfcal exenination of "A" helium circulator pelton'whcc) indicates cracking in the t.ceth of the coupling. This is considered an abnorr.'.a1 occurrence per item 2.1(f) of the Technical Specifications.
CONDITIONS PRIOR TO OCCURRENCE:
Steady State Power Routine Shutdown Hot Shutdown Routine Load Change Cold Shutdown X
Other (specify)
Refueling Shutdown Helium circulator had been Routine Startup removed to inspect faulted static neal bellows.
Exam-ination of pelton whec1 in-cated potential problems.
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't The major plant paraneters at the time of the event were as followa:
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Power
- PTR, fi/A IB!th h
- ELECT, li/A luic 1
D Secondary Coolant Pressure N/A psig hs
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Tenperature N/A
- F y
y.
Flow N/A
- /hr.
Primary Coolant Pressure N/A psig u(
Tc.mperature II/A
- F Core Inlet b'[!
N/A
- F Core Outlet h
Flow n/A
- /hr.
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"A" helium circulator had been removed from its normal position in the g
PCRV bottom head penetrati.on and had been replaced by the sparc due to probicas with the static seal bellows (see Abnornal Occurrence Report i
f50~267/74/13 dated July. 11, 1974).
Uclium circulator components were being examined in canufacturer's shops in San Diego.
4 DESCRIPTION OF ih OC_CURRENCE:
e Removal of "A" helium circulator from the PCRV due to static seal actuating bellows problems afforded us the opportunity to examine components of the
.i helium circulator in detail.
Examination of the " nuclear" pelton uhecl coupling area indicated some r;
cracking at the root of the coupling teeth.
Li 1;l APPAREUT CAUSE j
1 0F OCCURRENCE:
Design Unusual Service Cond.
Including Environment I
Manufacture Component Failure hl Installation /Const.
Other (specify) q 1
Operator Procedure j
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No cause or explanation of the condition noted has yet been determined.
Inves ti'-
nation is presently undcruay.
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- Page 3 ANALYSIS OF OCCURRENCE:
The circulator had been operated at various velocities over its entire speed range (up to 10,000 rpm) using the Pelton turbine for approximately 450 hours0.00521 days <br />0.125 hours <br />7.440476e-4 weeks <br />1.71225e-4 months <br />. No probicms were observed during operation.
Cracking at Pelton wheel coupling was found following removal of the circulator for other reasons.
CORRECTIVE ACTION:
This must wait until final determination of cause of cracks.
FAILURE DATA /S1 HILAR REPORTED OCCURRENCES:
See reports: October, 1973 To:
Dr. Donald Knuth Directorate of Regulatory Operations Deficiency Report, Fort St. Vrain !! alium Circulators Augu st, 1972 to:
Mr. F. E. Krucsi Directorage of Regulatory Operations Deficiency Report Fort St. Vrain 11clium Circulators PROGPRetATIC TMPACT:
Not yet determined.
CODEIMPAd:
None
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rederic E. Swart '
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