PLYMOUTH, Mass. (AP) – The Nuclear Regulatory Commission is investigating a report that a senior reactor operator fell asleep in the control room at Pilgrim Nuclear Station.

The NRC, which said the incident was brought to the federal agency’s attention in late August, notified plant officials about the incident on Aug. 26.

Plant officials subsequently suspended the entire crew that worked the shift on the night in question, June 29, and the napping operator and a co-worker who took his picture sleeping with a cell phone camera were let go.

“The inattentiveness can’t be tolerated, but secondly, the employee that filmed the senior reactor operator did not immediately report the potential safety condition,” said David Tarantino, a spokesman for Pilgrim, a 670-megawatt power plant owned by the conglomerate Entergy.

The operator’s nap was brief, and never posed a threat the public, said the NRC, which was notified of the incident by a third party.

The NRC requires that several people staff the control room on each shift, and the plant met that requirement on the night of June 29, the agency said.

NRC spokesman Neil Sheehan said that the operator’s nap appears to have been an isolated event.

The NRC is developing rules that would limit the number of hours plant operators can work. Currently, there are only guidelines, published in 1982 after the Three mile Island disaster in Pennsylvania, recommending a 40-hour week and shifts no longer than 16 hours.

Mary Lampert, director of the anti-nuclear group Pilgrim Watch, said the case was “something that you’d see in the Simpsons (TV show), and you’d laugh.

“But you don’t laugh when you recognize the consequences of a disaster at a nuclear power plant,” she said.