Several states have no emergency evacuation plans for nuclear facilities within their borders because military security has prevented them from even knowing the facilities exist, a congressional subcommittee was told yesterday.

J. Dexter Peach, director of the General Accounting Office's division of energy and minerals, said six states without any plans has told his office that none were needed because there were no nuclear plants. "Interestingly enough, some of these . . . actually have classified nuclear facilities within their borders," Peach said.

He told the House Armed Services subcommittee that he could not identify the states for the same security reasons that had kept state officials in the dark.

The danger at these locations, Peach testified, includes accidental weapons detonations that could release massive amounts of radiation. The committee clearly took that to refer to nuclear weapons blasts, but Peach said later he had been referring to conventional arms detonations that might damage nearby nuclear weapons or experimental facilities and thereby release radioactive materials.

"We are not talking about a hydrogen bomb going off over six counties," Dwayne Weisel of the GAO declared after the meeting.

The Congressman, however, worried about bigger blasts.

"We're talking about radiation in a 50-mile radius, not just in 10 miles as at Three Mile Island," said Rep. Donald J. Mitechll (R-N.Y.), referring to the March 28 accident at Middletown, Pa. "If we were worried about this one, we ought to be terrified of that."

"I share your terror," said peach.

He recommended that military officials be instructed to confer with state and local preparedness leaders, perhaps on a classified basis, so that the communities might prepare for an emergency. Committee members expressed interest in preparing local National Guard units to handle any crisis. A general beefing-up of overall civil defense preparations could well include requiring readiness for a nuclear accident, said the subcommittee chairman, Rep. Lucien N. Nedzi (D-Mich.).

Joseph Hendrie, chairman of the Nuclear Regulatory Commission, told the subcommittee that it would cost about $150 million to bring all 50 states into compliance with NRC guidelines on evacuation plans by the year 2000. Peach reiterated an earlier recommendation that no further operating licenses be issued for nuclear power plants in states without NRC-approved emergency evacuation plans.