Two years after President Carter called for permanent government inspectors at each of the nation's nuclear power plants, more than two-thirds of the plant sites, including the Three Mile Island facility, are without an inspector.

Carter, as part of his overall energy policy proposal, announced in April 1977 that he would ask the Nuclear Regulatory Commission to assign a permanent inspector to each nuclear power plant and take other steps to ungrade safety and inspection proce dures.

However, the administration did not ask Congress for funds for the permanent inspector program until nine months later, and the first inspector was not assigned to a power plant until well over a year after the message.

It also remained unclear yesterday how well other aspects of Carter's announced plans to improve NRC safety and inspection services have been carried out.

There are now 70 operating nuclear reactors licensed by the NCR at 48 power plant sites around the country. According to NRC officials, 14 sites have permanent inspectors, while six other inspectors are assigned to sites where reactors are under construction.

In addition, the NRC yesterday dispatched three inspections to power plant facilities with reactors similar to the one at Three Mile Island, near Harrisburg, Pa.

In an April 20, 1977, "fact sheet" issued in connection with the president's energy message, the White House announced several planned steps on nuclear power safety.

"Although light water reactors have had a good safety record, the president will request the Nuclear Regulatory Commission to expand its audit and inspection staff, to increase unannounced inspections and to assign a permanent inspector to every nuclear site," the document said.

"The president will request the NRC to make mandatory the current voluntary reporting of minor mishaps and component failures," it added.

According to figures supplied by the Occied of Management and Budget, the NCR's inspection staff has grown from 137 authorized positions in fiscal 1979 to 147 in the administration's fiscal 1980 budget request, an increase of less than 10 percent.

White House press secretary Jody Powell, quoting NRC's inspections of nuclear facilities are unannounced. But neither Powell nor Frank Ingram, deputy public affairs officer for the NRC, could say how much the number of unannounced inspections has grown since April 1977.

Ingram also could not say what had resulted from the president's request to require reporting of "minor mishaps and component failures."

Ingram said that one reason only 20 inspectors are permanently assigned to nuclear power sites is the long training time involved, which he estimated at one to two years.

Eliot R. Cutler, associate director of the Office of Management and Budget for natural resources, energy and science, said the NRC began training permanent inspectors in 1977, using already appropriated funds. The first administration request for funds for the program went to Congress in January 1978 for the fiscal year that began last Oct. 1, he said. The first permanent inspectors were assigned to power plants late last year, he added.

Cutler said the inspector program is on schedule, with the NRC planning to have inspectors at 45 sites this year and 87 sites by 1981.