Air Force Col. Herbert Charles McClammy, 46, an assistant director for nuclear research development and testing for military applications for the Department of Energy died at Mt. Vernon Hospital Tuesday after an apparent heart attack.

Col. McClammy, a metallurgy specialist, was assigned to his nuclear work four years ago and remained with it when it became part of the Department of Energy.

Before that, he had been on the faculties of the Air Force Academy and the Air University at Maxwell Air Force Base in Montgomery, Ala.

A native of Wilmington, N.C., he earned a bachelor's degree in mechanical engineering from the University of Florida in 1953. He later earned a master's degree in aeronautical engineering from the Air Force Institute of Technology at Dayton Ohio, and a doctorate in business administration from Auburn University.

Col. McClammy was a member of Sigma Xi, a scientific society, and the American Society for Metals.

Survivors include his wife, Martha, and three children, James Scott, Martha Ann and Richard Alan all of the home in Alexandria, his mother Jeanette Pleasants, and his stepfather Ben Pleasants of Reidsville, N.C.; two sisters Deane Klimpel of New York City, and Carlyn Kriegel, of Atlanta, and a stepbrother Ben Pleasants of Los Angeles.