Robert S. Rochlin, a nuclear physicist who worked for the U.S. Arms Control and Disarmament Agency for more than three decades, died Aug. 25 at the Riderwood retirement community in Silver Spring. He was 91.

The cause was complications from dementia, said his wife, Janet S. Rochlin. He was a longtime Chevy Chase resident.

Dr. Rochlin, who retired from the disarmament agency in 1996, had served in positions including chief scientist in several bureaus and deputy assistant director of the nonproliferation bureau. Earlier in his career, he worked for more than a decade for General Electric in Schenectady, N.Y.

Robert Sumner Rochlin was born in Yonkers, N.Y. He received a bachelor’s degree in electrical engineering in 1944 and a doctorate in nuclear physics in 1952, both from Cornell University in Ithaca, N.Y. He served in the Navy at the Naval Research Laboratory in Washington from 1944 to 1945.

His professional honors included an award from the U.S. Arms Control and Disarmament Agency. He helped lead an effort in Maryland for universal health care, his wife said, and did advocacy work to promote public financing of political campaigns and to prevent young people from using tobacco.

Survivors include his wife of 63 years, Janet Stemerman Rochlin of Silver Spring; two children, David Rochlin of Denver and Linda Ruben of Fair Oaks, Calif.; a sister, Ellen Godwin of Springfield; and five grandchildren.

— Emily Langer