Federal regulators have begun an inspection of the Millstone Unit 2 nuclear power plant to review problems associated with a leaking relief valve.
The Nuclear Regulatory Commission said two inspectors arrived Tuesday to review issues related to the "unusual event" declared Oct. 4 at the Connecticut facility. It was the lowest of four levels of emergency classification.
NRC Region I Administrator Dan Dorman said the initial review of the event raised questions regarding operator performance.
Spokesman Ken Holt said Millstone is investigating and "looking for opportunities to improve performance."
Millstone, owned by Dominion Resources Inc., was preparing a refueling and maintenance outage when the incident occurred. A reactor coolant system leak was linked to a relief valve on the shutdown cooling system used to provide cooling when the reactor is out of service.