There should be an extra operator in the control room of every nuclear in the control room of every niclear plant in the United States and the chief operator should be freed of all duties except directing the three operators under his cm ommand.

Those were the recommeddations to the Nuclear Regulatory Commission from a task force set up to look into the March 28 accident that shut down the nuclear plant at Three Mile Island in Pennysylvania. The task force also recommended that if a nuclear plant loses any backup safety device for 24 hours it be required to shut down to correct the loss.

"By a safety device, I mean things like the closing of two feedwater valves that were out of service the day of the accident at Three Mile Island," the NRC's Roger W. Mattson said. "I also mean things like the loss of an emergency power supply or an inoperative emergency core cooling system."

Mattson said the task force recommended adding a fourth operator [with the title of shift safety engineer] to nuclear plant control rooms because the three operators on duty at Three Mile Island had too many things to do the day of the accident.

He also suggested relieving the senior shift operator of all administrative duties so he could concentrate exclusively on directing the three other operators in time of accident. The senior operator should not have to manipulate any controls, Mattson said, so he can pay continued attention to what is going on throughout the control room.

"We found that during their shifts senior operator do things like procuring equipment and filling out NRC forms," Mattson said. "We want a man removed from these responsibilities so he can be in a position to make decisions."

Mattson said it should also be clearly understood that one operator is definitely in charge, something that was not clear at Three Mile Island the morning of March 28.

"We found a lack of attention to recognition of the commond and control function at Three Mile Island," "mattson said. "It was never clear that anybody was completely in charge during the first few crisis hours."

Mattson estimated that the changes the task force recommended would cost the 71 nuclear plants operating in the United States at least $2 million each and would take "several months to a year and a half" to implement, depending on the plant's age and length of operating service.