ML20155J113
| ML20155J113 | |
| Person / Time | |
|---|---|
| Site: | University of Michigan |
| Issue date: | 10/29/1998 |
| From: | Simpson P MICHIGAN, UNIV. OF, MEDICAL SCHOOL, ANN ARBOR, MI |
| To: | Michaels T NRC (Affiliation Not Assigned) |
| References | |
| REF-PT21-98 NUDOCS 9811120032 | |
| Download: ML20155J113 (1) | |
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MICHIGAN MEMORIAL-PHOENIX PROJECT e
y PHOENIX MEMORIAL LABORATORY FORD NUCLEAR REACTOR ANN ARBOR, MICHIGAN 48109-2100 October 29,1998 fga4 Theodore S. Michaels, Senior Project Manager U.S. Nuclear Regulatory Commission Non-Power Reactors and Decommissioning Project Directorate Division of Reactor Program Management Office of Nuclear Reactor Management Washington, D.C. 20555-0001 Re: Initial Notification of a Discovered System Deficiency: Failure of Reactor Building Ventilation Supply and Exhaust Dampers to Close Description ofEvent On Wednesday October 28,1998 at approximately 10:30 a routine daily surveillance discovered that the air cylinder that operates the reactor building ventilation supply and exhaust dampers was hanging up. The dampers would not automatically close as a result. Initial maintenance efforts by the reactor staff to establish proper operation were unsuccessful. At 11:12 the reactor was shut down and will remain shut down until normal operation of the supply and exhaust dampers is restored.
Background
The reactor building confinement system exists to minimize the release of radioactivity to the unrestricted area in the event of a major experiment or fuel element failure. The reactor building ventilation supply and exhaust dampers are a part of the confinement system. The dampers are designed to close automatically when the building alarm is actuated by abnormally high radiation levels detected i: the reactor building exhaust air (> 1 mrem /hr), if the fuel vault criticality monitor alarms or by operator action.
However, when a building alarm occurs one of the initial actions taken by the con ; ole operator under Emergency Procedure 101 is to verify the that the supply and exhaust dampers are closed. The operator would take action to manually close the dampers if they had not automatically closed Thus, the potential for a significant additional release of radioactivity to the unrestricted area is minimal if an event triggers the building alarm and the dampers do not automatically close.
' Corrective Actions
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The initial corrective action taken was to shut down the reactor. The reactor will remain shut down until the damper cylinder is.mpaired. UM plant has been contacted and arrangements made to inspect and repair the damper cylinder. Additional corrective actions may be warranted based on the damper cylinder mspection.
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Since ly, Philip. Simpsoif' Interim Reactor Manager xc:
Thomas Burdick, U.S. NRC John Lee, Interim Director MMPP FNR Safety Review Committee FNR Staff
..; s. i 1M 9811120032 981029 "
PDR ADOCK 05000002 8
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a Phone:(734) 764-6220 Fax: 734)936-1571 www.umich.edu/-mmpp/