Transformer Fault and Partial Power Loss Provoke NRC Inspection at Clinton Nuclear Plant

A ground fault that cut power to some systems at the Clinton nuclear plant in Illinois has prompted an inspection from federal regulators.

On Friday, the Nuclear Regulatory Commission announced it sent boiling water reactor specialists and experts in electrical system design to conduct a supplemental inspection at the plant. They will scrutinize Exelon's root cause analysis, its response to the event and any corrective measures taken since.

On Dec. 8, operators shut the reactor down after NRC records indicate a transformer fault briefly cut power systems affecting containment ventilation and the reactor core spray. The shutdown proceeded normally and was not a threat to public or worker safety. Clinton is currently in the "licensee response" column of the NRC's action matrix, which indicates acceptable safety performance in the past.