Saul Levine, 61, a vice president of the NUS Corp. and a retired director of regulatory research at the Nuclear Regulatory Commission, died Oct. 18 at the Evanston Hospital in Evanston, Ill., after a heart attack.

Mr. Levine, a resident of Bethesda, was stricken while lecturing at Northwestern University.

Mr. Levine was born in Passaic, N.J. He graduated from the U.S. Naval Academy in 1945 and earned bachelor's and master's degrees at the Massachusetts Institute of Technology. In uniform and as a civilian, his subsequent career was in the nuclear field and he became an authority on safety in nuclear power plants and related matters.

His naval career included work on the Enterprise, the first of the nuclear-powered aircraft carriers, and on the Polaris submarine program. He resigned from the service in 1962 with the rank of commander,

In 1963, he went to work for the Atomic Energy Commission. With Dr. Norman Rasmussen of MIT, he helped lead the team that wrote the first comprehensive evaluation of the likelihood and consequences of nuclear power plant accidents.

When he retired from the government in 1980, Mr. Levine was director of the Office of Nuclear Regulatory Research at the Nuclear Regulatory Commission. He then joined the NUS Corp., whose interests include the nuclear power industry.

Mr. Levine received the Distinguished Service Award from the AEC in 1975.

Survivors include his wife of 39 years, Sylvia, of Bethesda; four children, David of Burlington, Mass., Robert of Rockville, Michael of Allentown, Pa., and Judith of Bethesda, and two grandchildren.