James R. Yore, 66, an attorney who retired in June as chairman of the Atomic Safety and Licensing Board Panel of the Nuclear Regulatory Commission, died Saturday at a hospital in Elkhorn, Wis., after a heart attack. He was stricken while on vacation in Delavan Lake, Wis.

Mr. Yore joined the Atomic Energy Commission, which later became the Nuclear Regulatory Commission, in 1947, soon after it was established. He was director of security at the AEC's Chicago office before transferring to this area in 1958.

He then served as assistant director of personnel security at AEC headquarters here and was special assistant to the AEC commissioner. In 1967, he became the first executive secretary of the Atomic Safety and Licensing Board Panel and was named panel chairman in 1975.

Mr. Yore, who lived in Bethesda, was a special agent for the Federal Bureau of Investigation for five years before joining the AEC. He was a member of the Society of Former FBI Special Agents.

In 1961, while on loan from the AEC, he served on the staff of the Senate Permanent Subcommittee on Investigations.

Survivors include his wife, Margaret, of the home; a daughter; Maureen Tieman, of Los Angeles; two sons, James, of New York City, and Brian, of Louisville, Ky., and one grandson.

The family suggests that expressions of sympathy be in the form of contributions to the American Heart Association.