ML18057B167
| ML18057B167 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 07/17/1991 |
| From: | Slade G CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9107230368 | |
| Download: ML18057B167 (2) | |
Text
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consumers Power l'OWERINli MICHIGAN'S l'ROliRESS Palisades Nuclear Plant:
27780 Blue Star Memorial Highway, Covert, Ml 49043 July 17, 1991 Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT -
GB Slade General Manager UNREVIEWED SAFETY QUESTION - POTENTIAL FOR LEAKAGE OF CONTAINMENT SUMP WATER TO THE SIRW TANK DURING AN MHA - ADDITIONAL INFORMATION Consumers Power Company (CPC) letter dated June 14, 1991 requested an exemption from the FSAR requirement to include passive component failure when determining the radiological consequences of a design basis loss-of-coolant accident.
The exemption request was specific to possible engineered safety feature valve leakage which could result in a higher than analyzed radioactive release through the Safety Injection and Refueling Water Tank (SIRWT) vent during the recirculation phase after a maximum hypothetical accident (MHA).
As an interim measure to minimize the possible amount of release to the atmosphere, CPC stated that by July 1, 1991 we expected to implement a procedure to route the SIRWT vent to a charcoal filter during the recirculation phase following a loss of coolant accident (LOCA).
After further evaluation, we have determined that instead of installing a SIRWT vent flow path through a charcoal filter, implementing a new valve line up to route any valve leakage to the south tilt pit in the spent fuel pool building and eventually through spent fuel pool building charcoal filter would be a more effective method of reducing the release.
On June 27, 1991, the NRC Palisades Project Manager was made aware of this change in plans and commitment.
This letter serves to close documentation initiated by our plan to route the SIRWT vent to a charcoal filter.
A new valve line-up was developed, reviewed and added to Emergency Operating Procedures EOP 4.0 and EOP 9.0.
We no longer plan to route the SIRWT vent through a charcoal filter during the recirculation phase after a LOCA.
A CMS ENERGY COMPANY
,,.,.,..i...
At the present time, we consider the new valve line-up an interim method of mitigating any possible post OBA radioactive release caused by valve leakage in the engineered safety feature valves referred to in our June 14, 1991 exemption request.
As implied in the June 14th transmittal letter, a permanent method to mitigate possible release from the SIRWT vent, either proven by analysis or made possible by procedure or hardware change, will be determined, approved and implemented before the beginning of Cycle 10 which is scheduled for April 1992.
Gerald B Slade Plant General Manager CC Administrator, Region III, USNRC NRC Resident Inspector - Palisades