Prairie Island unit 2 issued a brief unusual event declaration Tuesday as water temporarily dropped in the reactor coolant system.
Xcel Energy declared the unusual event at 6:24 a.m. after detecting an increase in reactor coolant system leakage, according to a statement from the Nuclear Regulatory Commission. At no point was public or worker health compromised, and the plant maintained “the appropriate level of water in the reactor,” the NRC reported.
A release from Xcel said further investigation did not show a leak. Plant operations were not affected, and no radioactive material was released. After a thorough assessment, Xcel cancelled the declaration at 11:36 a.m. the same day. An unusual event is the lowest of the Nuclear Regulatory Commission’s emergency categories.
Unit 2 at the plant near Minneapolis, Minn., was taken out of service on Feb. 21 for a routine refueling outage. In the process, operators manually tripped the reactor from 11.42 percent power following a feedwater heater alarm, according to an NRC event report. No safety injection or use of auxiliary feedwater systems was required, and no emergency event was declared.