WASHINGTON--Two key members of Congress yesterday criticized President Carter's Three Mile Island commission for failing to recommend a moratorium on the construction of nuclear power plants.

Rep. Morris K. Udall (D-Ariz.), chairman of the House Interior Committee, said that in the absence of a moratorium "there will be a tendency to use Band-Aids where surgery is required."

Udall had indicated that he opposed a moratorium as recently as last summer, but said he now believes that at least "a conditional moratorium" is needed.

Not so Hot

Sen. Gary Hart (D-Colo.), who chairs the Senate Nuclear Regulation Sub-committee, said he is "troubled by the commission's decision not to recommend a delay in construction of new plants" in light of its other findings.

The legislators made their remarks in opening statements prepared for a joint hearing on the findings of the presidential commission. The commission's chairman, Dartmouth President John G. Kemeny, and a majority of its members will defend their report at the hearing.

The report levelled a broad indictment at the nuclear industry and its regulators, but stopped short of recommending a moratorium--an issue which sharply divided the Commission.

No Government

Among the panel's recommendations was a call for the replacement of the Nuclear Regulatory Commission (NRC) with an executive agency headed by a single administrator. At present, the five-member NRC must make all major decisions by majority vote.

The commission also recommended that future atomic plants should be located away from populated areas.

According to an Assoicated Press-NBC News poll, a majority of Americans favor a halt in construction until the public safety can be assured.

There are now 70 commercial and two government-owned nuclear plants in the country. Another 91 are under construction or have construction licenses.