05000267/LER-1981-059, Forwards LER 81-059/03L-0.Detailed Event Analysis Encl

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Forwards LER 81-059/03L-0.Detailed Event Analysis Encl
ML20031H422
Person / Time
Site: Fort Saint Vrain 
Issue date: 10/14/1981
From: Warembourg D
PUBLIC SERVICE CO. OF COLORADO
To: Seyfrit K
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML20031H423 List:
References
P-81252, NUDOCS 8110270468
Download: ML20031H422 (4)
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LER-1981-059, Forwards LER 81-059/03L-0.Detailed Event Analysis Encl
Event date:
Report date:
2671981059R00 - NRC Website
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public Servlee Company f Odeirade Ve 16805 Road'19 1/2, Plattevi'le, Colorado 8065 "6,

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91 October 14, 1981

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OCT2 319sk.

Fort St. Vrain 2) u..,u m, Unit No. 1

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OCT I 91981 Mr. Karl V. Seyfrit, Director Nuclear Regulatory Commission i

Region IV Office of Inspection and Enforcement 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76012

Reference:

Facility Operating License No. DPR-34 Docket No. 50-267

Dear Mr. Seyfrit:

Enclosed please find a copy of Reportable Occurrence Report No. 50-267/81-059, Final, submitted per the requirements of Technical Specification AC 7.5.2(b)2.

Also, please find enclosed one copy of the Licensee Event Report for Reportable Occurrence Report No. 50-267/81-059.

Very truly yours, WWY: =7

,v Don Warembourg Manager, Nuclear Production DW/cis i

Enclosure cc: Director, MIPC i.

8110270468 811014N DR ADOCK osooogs7 PDR

$6M S'ln

REPORT DATE:

October 14, 1981

. REPORTABLE OCCURRE!!CE 81-059 ISSUE O OCCURRENCE DATE:

September 14. 1981 Page 1 of 3 FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE COMPANY OF COLORADO 16805 WELD COUNTY ROAD 19 1/2 PLATTEVILLE, COLORADO 80651-9298

'cPORT NO. 50-267/81-059/03-L-0 Final 8

IDENTIFICATION OF OCCURRENCE:

On six occasions, with the plant operating at power, Class I shock suppressors (snubbers) were removed from service for inspection.

This is a degraded mode of LCO 4.3.10 and is reportable per Fort St.

Vrain Technical Specification AC 7.5.2(b)2.

EVENT

DESCRIPTION

From September 14 through October 8,1981, six operabia Class I snubbers were removed from service for inspection of the snubbor j

cylinder tie rods. These events c: curred as follows Event #1 On September 14, 1981, at 0845 hours0.00978 days <br />0.235 hours <br />0.0014 weeks <br />3.215225e-4 months <br />, with the plant operating at 70%

- power, BFS-30E was removed for inspection.

Inspection was completed, and the snubber returned to service at 1420 hours0.0164 days <br />0.394 hours <br />0.00235 weeks <br />5.4031e-4 months <br /> on September 16, 1981.

Event #2 On September 21, 1981, at 0805 hours0.00932 days <br />0.224 hours <br />0.00133 weeks <br />3.063025e-4 months <br />, with the plant operating at 70%

power, BFS-29E was removed for inspecticn.

Inspection was completed, and the snubber returned to service at 1200 hours0.0139 days <br />0.333 hours <br />0.00198 weeks <br />4.566e-4 months <br /> on September 23, 1981.

Event #3 On October 5,

1981, at 0900 hours0.0104 days <br />0.25 hours <br />0.00149 weeks <br />3.4245e-4 months <br />, with the plant operating at 70%

power, BFS-54 was removed for inspection.

Inspection was completed, and the snubber returned to service at 1125 hours0.013 days <br />0.313 hours <br />0.00186 weeks <br />4.280625e-4 months <br /> on October 6, 1981.

Event #4 On October 6,

1901, at 1240 hours0.0144 days <br />0.344 hours <br />0.00205 weeks <br />4.7182e-4 months <br />, with the plant operating at 70%

power, BFS-74E was removed for inspection.

Inspection was completed, and the snubber returned to service at 1400 hours0.0162 days <br />0.389 hours <br />0.00231 weeks <br />5.327e-4 months <br /> on October 6, 1981.

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REPORTABLE OCCURRENCE 81-059 TSSUE O Page 2 of 3 l

Event #5 On October 6,

1981, at 1500 hours0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.7075e-4 months <br />, with the plant operating at 70%

power, BFS-167E was removed for inspection.

Inspection was completed, and the snubber returned to service at 1400 hours0.0162 days <br />0.389 hours <br />0.00231 weeks <br />5.327e-4 months <br /> on October 7, 1981.

Event.#6 On October 8,

1981,at0815 hours,withtheplantoperatingat70h power, BFS-204E was removed for inspection.

Inspection was completed, and the snubber returned to service at 1115 hours0.0129 days <br />0.31 hours <br />0.00184 weeks <br />4.242575e-4 months <br /> en October 8, 1981.

CAUSE

DESCRIPTION:

The cause of degraded mode operation in each instance was the removal of snubbers from service while the reactor was at power.

The snubbers in question had been araviously found to have-1/4" diameter cylinder tie rods instead of the standard 3/8" diameter cylinder tie rods, and inspection was necessary to determine if the tie rods had been over-torqued when installed.

CORRECTIVE i

ACTION:

Each of the snabbert, except BFS-74E, were disassembled and the tie-rods inspected. None were found to be out of tolerance.

The tie rods for BFS-74E were found to be 3/8" rods, and further inspection was not required.

Following testing, the snubbers were returned to service.

Maintenance Procedure 98.1 was revised ps

'TT Grinnell recommendations to include torque requirements for les cylinder tie rods.

No further cerrective action is anticipated or required.

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T-l REPORTABLE OCCURRENCE 81-059 i

ISSUE O Page 3 of 3 Prepared By:

Paul Moore 3

Technical Services Technician Reviewed By:

(3caAv NS L Charfes Fuller

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Technical Services Engineering Supervisor l

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Reviewed By:

Edwipf 37 Hilf V Station Manager Approved By:

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Don Warembourg f[

Manager, Nuclear Protuction i

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