Nuclear Event – Unanalyzed condition (degradation of Spent Fuel Pool racks neutron absorbing material): Pilgrim Nuclear Power Station, Plymouth, MA
Nuclear Event in USA on Thirsday, 12 May, 2016 at 16:47 [EDT]
DETERIORATION OF SPENT FUEL POOL RACK NEUTRON ABSORBING MATERIAL
“On May 12, 2016, at 16:47 EDT with the reactor at 100% power and the mode switch in RUN, an assessment of the Spent Fuel Pool racks containing neutron absorbing material concluded that some degradation had occurred. The result is that we cannot assure we are maintaining Keff < 0.95 as required per design. Conservative measures have been implemented to ensure public health and safety.
“Recent planned testing conducted in the spent fuel pool determined that one rack panel had degradation of the neutron absorbing material in excess of what had been analyzed. An extent of condition review indicated additional potential at-risk locations may exist. Analyses are being performed to determine the potential impact and mitigating actions. Fuel pool conditions are safe and stable. Conservative measures have been implemented and spent fuel safety is maintained.
“Based on the above, the condition is reportable to the NRC as an Unanalyzed Condition under 10 CFR 50.72(b)(3)(ii), and requires an 8 hour notification. The condition is also reportable in accordance with 10 CFR 50.73 (a)(2)(ii).
“The licensee has notified the NRC Senior Resident Inspector.
“The licensee will notify the Commonwealth of Massachusetts.”