During routine Criticality Accident Alarm System (
CAAS) maintenance on July 20, 2021, UUSA [(URENCO
USA)] staff identified an area in which the
CAAS alarm was not clearly audible. The alarm was (and is) functioning, but not at an adequate level of sound pressure to meet the acceptance criteria. UUSA arranged compensatory measures which achieve an equivalent safety function within
24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> in the affected area. The affected area was in the Immediate Evacuation Zone (
IEZ), outside of the area in which licensed
special nuclear material is handled, used, or stored.
On September 16, 2021, an NRC inspector conducting an onsite inspection informed UUSA staff that given the potential that the alarm had not been clearly audible for a period of time between surveillances, this event should have been reported within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to the NRC in accordance with 10 CFR 70.50(b)(2) in which equipment is disabled or fails to function as designed when required by regulation (10 CFR 70.24).
The licensee will notify the NRC Region 2.