ML18051B310
| ML18051B310 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 03/12/1985 |
| From: | Johnson B CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.B.1, TASK-TM NUDOCS 8503150070 | |
| Download: ML18051B310 (2) | |
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consumers Power company General Offices: 1945 West Parnall Road, Jackson, Ml 49201 *.{517) ?SS-0550 March 12, 1985
- Director, Nuclear Reactor Regulation US Nuclear Regulatory Commission Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT ~ SUPPLEMENTAL RESPONSE -
NUREG-0737, ITEM II.B. l, REACTOR COOLANT SYSTEM VENTS NRC letter dated November 7, 1983 and entitled NUREG-0737, Item II.B.l, Reactor Coolant System Vents, identified the need to confine acceptable resolution of the susceptibility of reactor coolant gas vent system (RCGVS) valve systems to common mode failures.
This submittal addresses this item relative to the installed system at the Palisades Plant.
The.cqmmon mode problem exhibited by RCGVSs utilizing a Target Rock valve system involves the spurious opening of the downstream solenoid operated pilot valves caused by the pressure pulse which is initiated from the opening of the upstream vent valves.
The safety concerns identified with the problem are 1) the increased probability of failing more than one valve open, and 2) the increased hazard to personnel in the vent discharge area of containment.
The Palisades Plant has not experienced the subject common mode_pr9blem wbich other plants have experienced.
At Palisades, the valves are not tested while the reactor coolant system is pressurized.
By testing the valves in cold shutdown c9ndition*, the common mode problem is precluded during testing.
Additionally, the.valves are not routinely cycled, except during testing.
The probability of failing more than one valve open therefore, has not been increased.
Since the common mode problem is not likely to be experienced at Palisades, there is no increased hazard to personnel due to unintentional valve lifting.
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Director, Nuclear Reactor Regulation Palisade Plant NUREG-0737, Item II.B.l March 12, 1985 In any event, the RCGVS discharge is located above the pressurizer and is directed upward toward the containment dome, away from routing personnel access.
Brian D Johnson Staff Licensing Engineer CC Administrator, Region III, USNRC NRC Resident Inspector - Palisades OC0385-0300A-NL02 2