ML20154J413
| ML20154J413 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 05/17/1988 |
| From: | Murphy W VERMONT YANKEE NUCLEAR POWER CORP. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| FVY-88-38, NUDOCS 8805260343 | |
| Download: ML20154J413 (3) | |
Text
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s VERMONT YANKEE NUCLEAR POWER CORPORATION FW 88-38 AD 5. Bcx 169, Ferry Road, Brattleboro, VT 05301 ENGINEERING OFFICE Sqgf 1671 WORCESTER ROAD FR AMINGHAM, M ASS ACHUSETTS 01701 Ttt EPnoNE so-a 72-a100 May 17, 1988 U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Attn:
Document Control Desk
References:
a)
License No. DPR-28 (Docket No. 50-271) b)
Letter, USNRC to VYNPC, NVY 88-056, Inspection Report No. 88-03, Notice of Violation, dated 4/1/88 c)
Licensee Event Report 88-01
Dear Sir:
Subject:
Response to Inspection Report No. 88-03, Notice of Violation Violation "During a routine NRC inspection conducted on February 9 - March 21, 1988, a violation of NRC requirements was identified.
In accordance with the
' General Statement of Policy and Procedure for NRC Enforcement Actions,'
10 CFR Part 2, Appendix C (Enforcement Policy 1986), the viointion is listed below.
Technical Specification 3.9.A.1 requires service water (SW) system effluent radiation monitor operability to be in accordance with Table 3.9.1. Table 3.9.1 requires grab samples be obtained and analyzed every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> if the SW effluent radiation monitor is inoperable.
Contrary to the above, from August 22, 1987 to September 3, 1987 the SW effluent radiation monitor was inoperable and the required grab sampling was not accomplished.
This is a Severity Level IV Violation (Supplement 1)."
Response
1.
Reasons for Violation Our investigation of the events revealed that the violation was caused by a component failure and lack of recognition that removal of the circulating water (CW) system from operation would drain the service water system to a l
point where the service water effluent radiation monitor would not be operable.
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VERMONT YANKEE NUCLEAR POWER CORPORATION U.S. Nuclear Regulatory Commission May 17, 1988 Page 2 The failure of the flow through the SW effluent radiation monitoring system would normally have been indicated to the operators by the liquid process monitor flow switch causing a downscale indication. The flow switch, as a result of silt build-up within the switch, failed to provide the low flow indication to the operators.
Based on information readily available to the operators, it appeared that the SW effluent radiation monitoring system was working in a normal fashion. The system piping and instrument diagrams do not provide the kind of information that would allow an operator to suspect that by isolating the CW system the SW system would be drained. The failed flow switch did not provide an alarm to indicate that the sampling system was receiving an insufficient flow stream.
The logs taken of the instruments indicate that the SW effluent radiation monitoring system was indicating normal levels of radiation within the SW system.
2.
Corrective Actions (Immediate and Subsequent) a.
Immediate Actions Upon determination that the SW effluent radiation monitoring system was inoperative, the grab samples required by Technical Specification Table 3.9.1 were taken.
The moniotoring system was repaired.
The system was returned to service when the normal valve line-up for s
the service water and the circulating water system were returned to normal.
b.
Subsequent Actions The service water system procedure was revised to require that the operators check the function of the service water radiation monitor following shifting of the discharge mode.
The control room round sheets were revised to include a once/ shift check that the sarvice water radiation monitor readings are in the normal range (i.e. operable) and that there are no alarms present.
Cautionary statements have been added to the SW system procedure to prevent the SW system from being partially drained with the resultant tripping of the sample pump.
Chemistry personnel will continue their weekly check for flow at the monitor.
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. J VERMONT YANKEE NUCLEAR POWER CORPORATION 3'
U.S. Nuclear Regulatory Commission May 17, 1988 Page 3 Written information was provided to operations shift personne1' reiterating the monitoring system operation.
Investigations are being conducted into methods to reduce the poten-tial of silt build-up in the SW effluent radiation monitoring system flow switch.
In summary, we believe that the short-term and subsequent corrective measures fully address the violation.
We trust that the information provided above is acceptable; however, should you have questions or desire additional information, please contact us.
Very truly yours, VERMONT YANKEE NUCLEAR POWER CORPORATION d w f f **
Warren P/ Murphy Vice President an Manager of Operations
/dm cc:
J.T. Wiggins, Region I USNRC Regional Administrator, Region I USNRC Resident Inspector, VYNPC f
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