Lee V. Gossick resigned yesterday as operations director of the Nuclear Regulatory Commission, urging that the status and duties of the job be much more clearly defined.

Gossick, 59, had been under fire from some members of his impending dismissal have circulated for weeks. "The majority continued to support me," Gossick said in an interview. "I went because I think five years in this job is enough."

As operations director, Gossick was the main transmission channel between the five commissioners and the regulatory staff. He specialized in seeking consensus among the fractious commissioners, and the difficulty of that task often seemed to delay as many decisions as it fostered.

"There is a continuing problem of undefined responisibilities and authority in the position" of operations director, Gossick said. "It is urgent that the commission clarify what the relationship is for whoever they bring in to take my place."

Gossick added that despite the difficulties of trying to serve a divided commission, he would oppose any change to a single-administrator structure as recently proposed by the presidential commission that investigated the accident last March at Three Mile Island. "It is important that there be a counterbalancing of viewpoints," Gossick said.

Gossick, who retired as a major general in 1973 after 31 years in the Air Force, worked at the old Atomic Energy Commission as assistant director of regulation until the NRC was formed in 1975. He then became operations director for NRC.

NRC Chairman Joseph M. Hendrie accepted Gossick's resignation with "sincere regret," saying Gossick had carried out his job "in a highly effective manner in some difficult times for the agency."