Report issued by the Brookhaven National Laboratory discussing bulk grain irradiators. As stated in the abstract, "this report presents the results of a study to conceive, evaluate, review and estimate costs for a number of suitable designs for a Cobalt-60 Bulk Grain Irradiator; select a preferred type; and establish required criteria for future detail design and construction of the selected concept" (p. ii). This report includes tables, and illustrations.