05000267/LER-1980-065-03, /03X-1:on 801105,reactor Operated in Degraded Mode.Caused by Removal of Snubbers for Verification of Bleed Rate.Snubbers Were Adjusted & Replaced

/03X-1:on 801105,reactor Operated in Degraded Mode.Caused by Removal of Snubbers for Verification of Bleed Rate.Snubbers Were Adjusted & Replaced

ML19340E474
Person / Time
Site:	Fort Saint Vrain
Issue date:	01/09/1981
From:	Gahm J PUBLIC SERVICE CO. OF COLORADO
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19340E473	List:
References
LER-80-065-03X, LER-80-65-3X, NUDOCS 8101140630
Download: ML19340E474 (4)

LER-1980-065, /03X-1:on 801105,reactor Operated in Degraded Mode.Caused by Removal of Snubbers for Verification of Bleed Rate.Snubbers Were Adjusted & Replaced

Event date:
Report date:
2671980065R03 - NRC Website

text

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• E*CRT O ATE is0 EVENT DESCRIPTION AND PROS A8LE CONSEQUENCES h l3!2l lDuring nor=al operation, while verifying hydraulic snubber bleed rate, five Class 1 l

ydraulic snubbers were removed f rom service when the reactor was not in the shutdown l

,g,3, gg,,, ;cr refueling condition. This censtitutes operation in a degraded mode allowable by l

LCO 4.3.10 and is reportable per Fort St. Vrain Technical Specification AC 7.5.2(b)2.,

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Similar report RO 80-61.

There was no ef f ec t on the health or safety of the public.

,,g, la67l l The five snubbers removed f or test were VSS-101, VSS-104, VSS-107. VSS-110 and I

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40 ei 42 43 44 47 CAUSE CESCRIPTION AND CO ARECTIVE ACTIONS h i i i o ; ]Non-bleeding hydraulic vent stack saubbers were reolaced bv snubbers with bleed caea-l l-lij gbility. Engineerinz evaluation decet nined that the bleed rate should be zero and the 1 l

(snubbers were adiusted to zero blaed rate in olace. Five stubbers were renoved.

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Januarv 6, 1981 REPORTABLE OCCURRENCE 80-65 ISSUE 1 OCCURRENCE DATE:

November 9, 1980 Page 1 of 3 FORT ST. VRAIN NUCLEAR GENERATIm STATION PUBLIC SERVICE COMPANY OF COLORADO 16805 WELD COUNTY ROAD 191/2 PLATTEVILLE, COLORADO 80651 REPORT NO. 50-267 /80-65 /03-X-1 Revised Final IDENTIFICATION OF OCCURRENCE:

During November,1980, five Class I hydraulic shock suppressors were removed from service, one at a time, for test. Each event constitutes operation in a degraded mode allowed by LCO 4.3.10 and is reportable per Fort St. Vrain Technical Specification AC 7.5.2(b)2.

EVENT

DESCRIPTION

On five occasions, while the reactor was at power, operable Class 1 shock suppressors (snubbers) were removed from service for test:

VSS-110 - out of service from 0845 hours0.00978 days <br />0.235 hours <br />0.0014 weeks <br />3.215225e-4 months <br /> to 1235 hours0.0143 days <br />0.343 hours <br />0.00204 weeks <br />4.699175e-4 months <br /> on November 5, 1980 VSS-101 - out of service from 1305 hours0.0151 days <br />0.363 hours <br />0.00216 weeks <br />4.965525e-4 months <br /> on November 5,1980, to 0950 hours0.011 days <br />0.264 hours <br />0.00157 weeks <br />3.61475e-4 months <br /> on November 6,1980 VSS-104 - out of service from 1007 hours0.0117 days <br />0.28 hours <br />0.00167 weeks <br />3.831635e-4 months <br /> to 1100 hours0.0127 days <br />0.306 hours <br />0.00182 weeks <br />4.1855e-4 months <br /> on November 6, 1980 VSS-111 - out of service from 1325 hours0.0153 days <br />0.368 hours <br />0.00219 weeks <br />5.041625e-4 months <br /> on November 6,1980, to 1745 hours0.0202 days <br />0.485 hours <br />0.00289 weeks <br />6.639725e-4 months <br /> on November 7,1980 Technical Specificaciou LCO 4.3.10 states that all shock suppressors on i

Class 1 piping systems shall be operable if the reactor is not shutdown or refueling. The LCO further statas that continued power operation af ter a snubber is determined to be inoperable is permissible only during the suc-ceeding 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> unless the snubber is made operable sooner or replaced.

The five vent stack snubbers removed for test were returned to service with-l in the allowed 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> in all cases.

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REPORTABLE OCCURRENCE 80-65 ISSUE 1 Page 2 of 3

CAUSE

DESCRIPTION:

During performance of the hydraulic snubber functional test required each refueling by the Fort St. Vrain Technical Specifications, it was found that the 16 vent stack snubbers did not have bleed capability. This was reported as part of Reportable Occurrence 79-13.

The 16 non-bleeding hydraulic snubbers were modified or replaced so that bleed capability was available.

During the evaluation of seismic restraints in accordance with I & E Bul-letin 79-14, it was determined that the bleed rate on these 16 snubbers shou'.d be zero.

The blsed rate of the 16 vent stack snubbers was adjusted to zero with the snt.bbers in place. In order to verify that the bleed rate is in f act zero, each snubber is being removed, cesced, and replaced. During November, 1980, five snubbers were removed from service for test, resulting in five events of operation in a degraded mode allowed by LCO 4.3.10.

CORRECTIVE ACTION:

Each of the five snubbers were returned to service af ter testing was com-ple ted.

No further corrective action is anticipated or required for the f ;ve vent stack snubbers noted in this report.

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REPORTABLE OCCURRENCE 80-65 ISSUE 1 Page 3 of 3 Prepared By:

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Richard R. Frost Technical Services Technician Reviewed By:

c-Tec a Services Supervisor Reviewed By:

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Frank M. Mathie Operations Manager Approved By:

W,o M Don Warembourg

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Manager, Nuclear Production