Operational health physics safeguards during transfer of 38 used Triga fuel elements

During the spring of 1974, the University of California, Irvine acquired 38 used Triga fuel elements. The health physics planning of the operation was designed chiefly by the Reactor Supervisor in conjunction with the Radiation Safety Officer. 13 transfer operations of three fuel elements each in a one-inch shielded transfer cask were required to take the elements out of the shipping cask, 70 feet through air, and lowered into a shielded transport cast. The latter was moved under the reactor compartment crane for final transfer to the reactor poll for storage. Radiation levels up to 2.7 roentgens per hour (r/hr) at a meter from the transfer cask were noted. Both Crane Operators served the entire eight-hour shift. The Reactor Crane Operator was often bathed in a 160 mr/hr field. The outside Crane Operator was often exposed at levels up to 80 mr/hr. Exposures as indicated by both body badges during the operation were well below monthly exposure levels, even when radiation exposures from normal reactor operation were added in. Aspects of the handling operation, dry runs, additional shielding, and field dosimetry played a large part in achieving a relatively low exposure to the very few people utilized for this extensive operation