The Nuclear Regulatory Commission staff, faced with a blast of outrage from the Presidential Commission on the Accident at Three Mile Island, beat a hasty retreat yesterday from its decision to resume processing applications for new nuclear power plants.

The 12-member presidential commission dropped its planned agenda and instead spent three hours grilling NRC official Harold R. Denton on his move to lift a three-month freeze on the permit work. "The NRC seems to be thumbing its nose at this commission," said commission member Carolyn Lewis.

The commission may make recommendations that would further delay or vastly alter the licensing process, several members said. "What you're saying is that you can ignore the recommendations," Arizona Gov. Bruce Babbitt told Denton.

Denton, head of reactor regulation at the NRC, responded that the NRC will require 24 changes in design and operations in all new and operating plants and that those changes will not foreclose any recommendations the commission might make.

"Mr. Denton, I think you're kidding me," Babbitt snapped.

Denton returned after lunch to announce that he will defer any further action on operating license and construction permit applications until the full NRC considers the presidential commission views.

"I just totally misjudged the way they would think about it," Denton said later. "I thought their interests would be in staying out of the day-to-day licensing process . . . I guess I was just ignorant."

The commission voted to summon the full NRC, by subpoena if necessary, to testify on the question of resuming work on licenses. Commissioner Richard T. Kennedy, the only one of the five nuclear regulatory commissioners not on vacation or out of town, appeared hurriedly, but stopped short of assuring the panel that licensing would not resume.

"The commission has taken no position in respect to this memorandum" of Denton's announcing the move, Kennedy said. But he promised to consider the panel's views "with the greatest of seriousness."

Panel member Theodore B. Taylor, a physicist and reactor specialist at Princeton University, said the group was worried about "a message going out worldwide that the lessons from Three Mile Island have been learned already."

Chairman John G. Kemeny, president of Dartmouth College, admonished Denton for assuming the commission would not be interested in the licensing process. "I would be very surprised if this commission did not recommend changes in the licensing process," he said.

He told reporters at the noon break that his concern was not with "hardware questions" but with the regulatory process itself. The panel has no quarrel with the list of technical changes the NRC staff wants reactor operators to make, he said.

Commission member Harry McPherson, a former adviser to President Johnson, told Denton the staff action, its timing and its failure to notify the commission in advance were all examples of poor management and policymaking at the NRC. "These situations will result in future Three Mile Islands unless things are changed," he said.

The presidential commission is scheduled to report to President Carter no later than Oct. 25, but Kemeny said yesterday that it might issue an interim report if the NRC resumes licensing activity.

Denton stressed that although his staff might work on applications, no permits would be issued without the full NRC agreeing to them. The nearest operating licenses are at least a month away, he said. Those are Salem II in New Jersey and North Anna II in Mineral, Va.

Denton had announced his proposed move in a letter to the NRC last Monday and said he assumed a copy had been sent to the presidential commission. The panel members told him, however, that they had learned of it from an article in yestarday's Washington Post.

Did he not think he should have informed them personally, commission member Lewis asked Denton.

"I do now," he responded.