AbstractIn building a nuclear reactor of any type, the stage is reached at which a decision must be made as to what steels can be used in construction of each plant component. Nuclear engineers have recognized the limitations of some of the common steels in nuclear environments and are pointing out ways the steelmaker should go in devising steels with the nuclear and chemical properties more compatible with them.Methods of fabrication, mechanical property data and compositions of carbon and alloy, including low manganese, low residual element steels made for possible nuclear uses are summarized and compared with those of standard grades of carbon and alloy steels.The limitations on composition imposed by nuclear considerations, and selected data on experimental and commercially produced steels made to avoid these limitations, are outlined. Low manganese steels are commercially available; should the need arise, other compositions both carbon and alloy that are now experimental could be made.