On 7/26/18 at approximately 1355 PDT, the Building 103 laboratory facility ventilation exhaust system was disabled during a scheduled evacuation drill at the Vallecitos Nuclear Center (VNC).
The system was restored on 7/26/18 at approximately 1407 PDT. There were no active fissile material operations in Building 103, thus no unsafe condition existed, and no release of material occurred.
This event is being reported pursuant to the requirements of 10 CFR 70.50 (b)(2).
The licensee will notify the NRC Region 4 office.
- * * RETRACTION FROM SCOTT MURRAY TO HOWIE CROUCH AT 1031 EDT ON 8/7/2018 * * *
EN53527, made July 27, 2018, reported an event in accordance with 10CFR70.50(b)(2) in which the Vallecitos Nuclear Center Building 103 facility ventilation exhaust system was disabled for approximately 12 minutes.
At the time of the report, information regarding the special nuclear material (SNM) in the affected Building 103 areas was not available and a conservative decision was made that the ventilation system was required to prevent releases or exposures to radioactive materials exceeding regulatory limits or to mitigate the consequences of an accident.
Based on a subsequent review of SNM inventory records and additional survey measurements, it has been determined the event report should be retracted due to the minimal amount of SNM that could have been affected.
Notified R4 Fuel Cycle Decommissioning Branch and NMSS Enrichment and Conversion Branch.
Notified R4DO (Vasquez) and
NMSS Events Notification (email).