Two items from this morning’s NRC Event Reports:
1. The North Anna nuclear power plant notified the NRC that it had received a laboratory report from a water sample submitted on Feb. 17 from an on-site test well. The report indicated tritium at a level of 53,000 picocuries per liter (pCi/L) in the sample. The North Anna Event Report only says that the level of tritium exceeded “the voluntary reporting threshold of 20,000 picocuries per liter(pCi/L).” What the report didn’t say is that the Safe Drinking Water Act threshold is also 20,000 pCi/L. Had the tritium reached drinking water supplies at that level, it would have been two-and-a-half times the limit considered safe for consumption.
2. Tuesday evening, operators at the Prairie Island nuclear power plant in Minnesota were powering down the Unit 2 reactor in preparation for a refueling outage. At approximately 11 per cent power, the control room received a “Hi Hi Alarm” for the Feedwater Heater. Alarms can be tripped by high temperature or by high radiation levels or other parameters. The Prairie Island report did not specify what parameter tripped the alarm. All that is known is that operators manually scrammed the reactor. The report does not indicate that additional investigation of the cause of the alarm is underway.