ML20077A279

Telecopy RO 50-259/83036:on 830705,seven two-stage Target Rock Relief Valves Tested at Wyle Labs for as-found Set Pressure Failed to Lift within Allowable Range.Caused Under Evaluation.Valves Will Be Reset & Retested

ML20077A279
Person / Time
Site:	Browns Ferry
Issue date:	07/06/1983
From:	Coffey J TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
RO-50-259-83036, NUDOCS 8307220266
Download: ML20077A279 (2)

Text

i TRLRCOPY TO NRC USNRC ATL ANTn[Ju19$gg83 U. S. Nuclear Regulatory Commissior Region II 101 Marietta Street, BW r 3 Jill l'l All : 02 Suite 3100 Atlanta, Georgia 30303 BFRO-50-259/83036 Reported under Technical Specification 6.7 2.a.1 Date of Occurrence: 7/05/83 Time of Occurrence: 0930 hours0.0108 days <br />0.258 hours <br />0.00154 weeks <br />3.53865e-4 months <br /> Unit 1 Technical Specification Involved: 2.2.A Conditions Prior to Occurrence Unit 1 shutdown for refueling; unit 2 at 110 We, and unit 3 at 1,034 We. -

Identification end Descriotion of Cecurrence Through verbal' notification, we have received data indicating that seven of 13 two-stage Target Rock relief valves tested at Wyle Laboratories for as-found set pressure initially failed to lift within the allowable range.

Tabulated below are valve serial numbers, set pressures, as-found set pressures, and percent deviation for the first lift.

Valve Serial Number Set Pressure As-Found Percent Deviation 1060 1105 ill 1135 27 1070 1105 111 1156 4.6 1084 1105 111 1128 2.1 1068 1125 ill ~ 1137 1.07 1079 1115 111 1136 1.9 1075 1115 111 1016 -9.8 1027 1115 111 1158 2.9 The total average deviation is 2.54 percent.

Annarent Cause of Occurrence As stated in previous LERs (BFRO-50-260/8227, -259/8125, -296/8174), the cause is being evaluated with the manufacturer.

8307220266 830706 N/C -

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TELECOPY TO NRC July 6, 1983 BFRO-50-259/83036 (Continued)'

Other Related Events

Reference:

BFRO-50-260-8227, -296/8054, -259/8125, -296/8174. The evaluations performed in the referenced LERs remain valid in that this problem does not result in an overexposure condition of reactor vessel piping nor_ does it result in any appreciable increase in MCPR operating limit. Previous calculations performed by the General Electric Company indicated that for the previous unit 1 operating cycle, a total average deviation in relief valve setpoint of 5 0 percent could have existed with not significant effect on nuclear safety.

Corrective Action Taken or Planned These seven valves will be reset, and retested prior to installation.

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j A. Coff cting Power Plant Superintendent l

l Browns Ferry Nuclear Plant I

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