The paper emphasizes engineering implications of the effects of structure and composition on the irradiation sensitivity of steels. Theoretical considerations are discussed and reviewed as they relate to possible explanations for observations on the subject.

The structural aspects include primarily the type of metallurgical microstructure and the grain size and also the steel condition, that is, plate, forging, weld metal, or weld heat affected zone. The compositional factors are never quite separable from structural factors in a microscopic sense. Several interstitial elements, primarily nitrogen, carbon, oxygen, and hydrogen, have been investigated for their relationship to neutron radiation sensitivity. Substitutional elements, including nickel, copper, phosphorus, vanadium, sulfur, and boron, as constituents in steels have also been included. Copper and phosphorus are found particularly detrimental to radiation resistance when present in quantities above certain levels.