One of the chief congressional watchdogs over the nuclear power industry said yesterday he will call for a major inquiry into every phase of nuclear power generation to find out if the nation should remain committed to atomic electricity.

"The accident at Three Mile Island is one of those triggering events that brings on a nationwide debate," Rep. Morris K. Udall (D-Ariz), chairman of the House subcommitte on energy and the environment, said in an interview yesterday. "I want the Congress to play a lead role in this debate and I want to hold hearings to find out what happened at Three Mile Island and how it impacts the future role of nuclear energy in America."

Udall said he plans to start hearings on the Three Mile Island accident after this month's Easter recess, then move on to discuss the effects of that accident on the 71 other U.S. nuclear plants in operation and the more than 90 plants under construction.

From there, Udall said, he will press the Energy Department on its announced plan to allow construction of 500 to 1,000 more nuclear plants by the year 2000. Udall said he wants to go into the siting and licensing speedup called for by Energy Secretary James R. Schlesinger, especially in light of the Three Mile Island accident that almost forced a massive evecuation of the Harrisburg, Pa., vicinity over the weekend.

"Do we put these plants in the future in remote areas, do we build them underground?" Udall asked. "Should these additional nuclear plants be encouraged or discouraged? These are the questions I want answers to."

The Arizona Democrat said he wants to investigate whether safety features are adequate for today's nuclear plants. He said he wonders why workers had to volunteer to enter the highly radioactive containment building at Three Mile Island to open a manual relief value to get rid of a hydrogen bubble threatening to explode inside the reactor.

"Why can't we have a relief valve that can be remotely operated," Udall asked "to get a hydrogen bubble out of there?"

Beyond safety questions, Udall said he would look into whether to repeal the Price-Anderson Act, which limits insurance claims on unclear accidents to $560 million. Any number of federal aides have already worried that cleanup costs and insurance claims will exceed $1 billion for the Three Mile Island accident.

"I want to find out if we've adequately assessed the costs of nuclear power," Udall said. "It's quite possible that Price-Anderson understates those costs."

Finally, Udall said he plans to question why the United States still has no national policy to dispose of the radio-active waste produced by generation of nuclear power. Said Udall: "We must decide as a country to resolve this question."

While Udall was calling for what he said should be a "comprehensive" inquiry before acting, Sen. George McGovern (D.S.D.) said yesterday he will introduce a bill Monday to halt further licensing of nuclear plants until there is an independent review of all possible safety defects in nuclear reactors.

At the same press conference, Daniel Ford, executive director of the Union of Concerned Scientists, called for the president "to seek the immediate removal" of Dr. Joseph M. Hendrie as chairman of the Nuclear Regulatory Commission.

Ford said Hendrie was "not fit to be a nuclear regulator." He said Hendrie has participated in a "far-reaching cover-up of critical nuclear safety difficulties."

Udall insisted the nuclear inquiry will be slow and deliberate.