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MANAGING EFFLUENTS DURING A FAILED FUEL INCIDENT ABSTRACT On July 26, 2000 Oyster Creek Nuclear Station experienced a multiple-pin fuel failure event. On that date, routine plant Chemistry sampling noted a 100-fold increase in Reactor Coolant Dose Equivalent Iodine (DEI) values and Off Gas sum of six values increased about ten times. On July 28, 2000 suppression testing was performed to determine the core location of the failed fuel bundles. Following this an action plan was developed to limit power changes and total power, increase hydrogen injection (HWC) and set up a daily conference call to Global Nuclear Fuels in Wilmington, NC. Since the failure occurred a little over two months prior to the plants scheduled refueling outage (18R), there was concern over increased BRAC point dose rates during the outage as well as increased dose to plant personnel prior to the outage. Given that the suppression testing identified the core location of the damaged fuel bundles, control rods were inserted at these locations in order to suppress fission and accompanying leakage of fission products. As expected, plant effluents increased as a result of the fuel failure. Noble gas effluents peaked during August while iodine and particulate releases peaked during the month of September. Without the measures taken for suppression, increasing HWC, as well as limits to power changes, effluent releases could have been much higher. At no time did the plant exceed the NRC performance indicator for RETS/ODCM Radiological Effluents Occurrences. During 18R damaged fuel bundles were moved to the spent fuel pool where the three failed fuel bundles were inspected. Robert Artz |
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