ABSTRACT
This chapter discusses the proposed gamma sources, only spent fuel elements, cobalt-60, and the isotopes of cesium. It includes five "gamma" sources; namely: spent fuel elements, gaseous fission products, separated cesium-137, sodium24, and reactor activated indium. The spent fuel elements contain large quantifies of mixed fission products that emit beta and gamma radiation. Most commercial gamma irradiation facilities in operation are using cobalt60 as the source material. The availability of gamma source is essential if it is to be considered for use in an irradiation facility. The main factors contributing to the initial cost of an irradiation facility are the gamma source, the biological shielding, and the product conveyor system. Gamma rays are absorbed in materials in a manner such that for every equal increment of thickness of a material the same percentage of radiation is absorbed. In an irradiator not all of the radiation generated in a source is absorbed by the product to produce the desired effect.
