ML19276G898
| ML19276G898 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 08/20/1979 |
| From: | Counsil W NORTHEAST UTILITIES |
| To: | Grimes B Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7908280568 | |
| Download: ML19276G898 (2) | |
Text
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August 20, 1979 DOCKET N0. 50-245 Mr. Brian K. Grimes Acting Assistant Director for Systems Engineering Division of Operating Reactors U. S. fluclear Regulatory Commission Washington, D.C. 20555
Dear ffr. Grimes:
Attached, please find our response to the request for infomation concer-ning Target Rock safety / relief valves, as directed by your memo to boiling water reactor licensees dated July 16, 1979.
The long term program to improve valve reliability, as recommended by the General Electric Company, has been fully implemented at Millstone Unit 1. Please contact us if you require any additional infomation.
Sincerely, fiortheast fluclear Energy Company I
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W. G. Counsil Vice-President Attachment
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e RESPONSE TO REQUEST FOR INFORMATION TARGET ROCK SAFETY / RELIEF VALVES MILLSTONE NUCLEAR POWER STATION UNIT 1 Ref.:
Memo Brian K. Grimes to all boiling water reactor licensees dated July 16, 1979 1.
The Target Rock safety / relief valves installed on the Millstone ?
main steam lines were retrofitted from the Model 67F configuration to the Model 7567F configuration during the Spring 1979 Refuel Outage. This modification, implemented to improve valve reliability, consisted of installation of improved pilot stage and electropneumatic systems, changing the valves to 2-stage design and operation. The existing simmer margins are 60 psi for one (1) valve having a 1095 psig set pressure, 75 psi for one (1) valve hat ing a 1110 psig set pressure, and 90 psi for four (4) valves having a 1125 psig set pressure.
2.
Routine maintenance and testing is perfomed on these valves per Millstone 1 Technical Specifications, summarized as follows:
a)
During each operating cycle, a simulated automatic initiation of the APR Subsystem is perfomed, but excludes actual valve opening.
b)
During each operating cycle, with the reactor at low pressure, each valve is manually opened until operability has been verified.
c)
Three of the valves topworks are bench checked or replaced with a bench checked topworks each refueling outage. All six valves topworks are checked or replaced every two refueling outages.
d)
At least one valve is disassembled and inspected during each refueling outage.
3.
No maintenance on these valves in addition to that required by Millstone 1 Technical Specifications is planned. Modifications to these valves will be perfomed per vendor recommendations, although none are planned or anticipated at this time.
4.
Planned maintenance and any additional modifications to these valves will be implemented during the next refueling outage, projected for Fall, 1980.
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