The House yesterday agreed to loosen the regulatory strings on new nuclear power plants, rejecting critics' claims that the public's right to raise questions about safety would be short-circuited.

It passed a bill authorizing the Nuclear Regulatory Commission to permit initial operations of new nuclear plants without completing safety hearings, at which opponents often warn of safety hazards.

The change was a victory for the nuclear power industry, which contends that the hearings often provoke lengthy delays while plants lie idle until the hearing processes are exhausted.

Industry regulators are required to complete safety hearings before permitting the new plant to start up. Under the new provision temporary operating permits could be issued allowing new plants to get under way before hearings are completed.

That agreement was worked out in two House committees after industry officials argued that at least 11 new nuclear plants would be stalled pending lengthy hearings between now and the end of 1983.

By a vote of 304 to 90, critics lost an effort to eliminate the change. Reps. Toby Moffett (D-Conn.) and Edward J. Markey (D-Mass.) argued that the hearing process would be undermined and safety rules compromised at a time when the reliability of safety features are being challenged from Pennsylvania to California.

They claim that the industry has exaggerated claims of power plants being delayed. A report last month by the House Government Operations Committee concluded that no plant in the United States is being held up solely because of the hearing process.

The bill authorizes $486 million for the commission in fiscal 1982 and $513 million the following year. Most of the money is for nuclear regulatory research.