The U.S. Nuclear Regulatory Commission announced Monday afternoon that it was investigating the "unplanned radiation exposures" of three workers on April 3, a week earlier, at the Cooper Nuclear Station near Brownville, Neb.
The NRC said it did not believe the exposure exceeded its limits.
"Workers removed a long tube contaminated with highly radioactive material through the bottom of the reactor vessel, rather than through the top as is usually done, triggering radiation alarms," the NRC reported. "The workers set the tube down and immediately left the area."
The Cooper plant has a single boiling-water reactor of General Electric design. (GE is a part owner of NBCUniversal, which owns half of msnbc.com.)
Here's a map of the plant, which is about 25 miles from Nebraska City, Neb., and south of Omaha.
The full release from the NRC:
NRC SENDS SPECIAL INSPECTION TEAM TO COOPER NUCLEAR STATION
The U.S. Nuclear Regulatory Commission has begun a special inspection at the Cooper Nuclear Station to review the circumstances surrounding a maintenance procedure that led to unplanned radiation exposures to three workers. The plant, located near Brownville, Neb., is operated by the Nebraska Public Power District (NPPD).
Inspectors, who began their work Monday, will look at the circumstances and decision-making by NPPD officials that led to the exposures, review the licensee’s response to the event, calculate the exposures the workers received and review corrective actions taken to prevent a recurrence.
The incident occurred on April 3, when workers removed a long tube contaminated with highly radioactive material through the bottom of the reactor vessel, rather than through the top as is usually done, triggering radiation alarms. The workers set the tube down and immediately left the area. The licensee does not believe the workers received radiation exposures in excess of NRC limits.
“We want to understand why normal work practices were not followed, resulting in unplanned radiation exposures to three workers,” said Region IV Administrator Elmo E. Collins. “We want to take a look at the decision-making that contributed to this event.”
The team consisting of two NRC inspectors, began work Monday and will probably spend several days at the plant. They will write an inspection report on their findings within 45 days of the end of the inspection that will be made publicly available.