The Department of Energy’s Office of Enterprise Assessments (EA), in a June 24 report, identified some design and operational deficiencies with the criticality accident alarm system (CAAS) at the Y-12 National Security Complex in Oak Ridge, Tenn.
Fissile material operations at Y-12 pose the risk of a criticality accident, an uncontrolled nuclear reaction that could expose nearby facility personnel to radiation releases. The CAAS is meant to detect and offer immediate notification of these criticality accidents, initiating evacuation of workers from affected areas to locations away from high radiation hazards, EA said.
CAAS consists of radiation detectors, relay control circuitry, power supply, and annunciation devices, according to the report. The first two detect the criticality accident and signal to the annunciation devices to alert workers.
Y-12 currently has 51 CAAS detector systems in its inventory, with 36 deployed in the field and 15 maintained in a calibration lab.
The Office of Enterprise Assessments examined the CAAS in the site’s Buildings 9204-2E, 9212, 9215, and 9720-5. “Overall, the operability of CAAS is adequately being maintained and is verified through routine completion of surveillance testing requirements,” it found.
The report identified some deficiencies, including that the coverage area for the CAAS detectors installed in Building 9212 is not in compliance with operation limiting guidelines because of intervening shielding within the building, and that certain design requirements for some of the detectors have not been fully verified.