The staff of the Nuclear Regulatory Commission recommended yesterday that operators of nuclear power plants be given tougher training and be required to have more experience than they get today before winning their operator licenses.

In making its recommendations to the five-member Nuclear Regulatory Commission, the staff urged that the minimum nuclear experience requirement for senior operator applicants be doubled to two years and that they be required to hold an operator's license for at least six months before they can apply for a senior operator's license. At present, there are no such requirements.

The NRC staff also recommended that all operators be given more rigorous training and be required to take more frequent examinations to test their skills as operators. The staff suggested that the passing grade for written operator examinations be raised to 80 percent from 70 percent.

In all, the NRC staff made 16 recommendations on operator training and licensing in response to the accident last March 28 at Three Mile Island. Among the recommendations were requirements to make more frequent use of computer simulators in training exercises.

Following the Three Mile Island accident, which the NRC said was due at least in part to the human error of the oeprators there, the NRC found that 20 out of 107 persons employed as senior operators at U.S. nuclear plants did not have licenses. It found that 10 others had been licensed at plants where they were no longer working.

A survey done by the NRC of 66 operating nuclear reactors in the United States revealed that 25 licensed operators at 15 reactors had failed written examinations. The same survey showed that 28 senior operators failed written exams and that no less than 62.9 percent of all nuclear operators had low enough scores that they were required to attend lectures to sharpen their skills.

"Of those required to attend lectures, the average number of lectures attended per individual was more than one," the NRC said. "The maximum was a high of 11."

In making its 16 recommendatons, the NRC made a comparison between its standards and those set forth by the U.S. Navy for its engine room personnel in nuclear-powered submarines. The NRC found that the Navy had tougher standards.

The NRC said the Navy exercises more control over the selecton of its operators and insists on stiffer training once it selects them. For example, the NRC training program requires 500 hours of lectures while the Navy course lasts six months and covers 700 hours of classroom instruction.