Basic data on radiation characteristics and protection against radiation of fission products formed in a nuclear reactor or as a result of a nuclear explosion. Radiation characteristics - differential and total activity , U-Equivalents, effective spectrum of radiation - calculated for the division products U235 and U238, formed in the reactor, respectively, on thermal neutrons and neutrons of the fission spectrum , as well as products of instantaneous fission of U238 on fast neutrons (with an energy of 14 MeV), the thermonuclear explosion . The radiation characteristics of fission products are independently important for solving numerous engineering-physical, technical and radiobiological problems, but they are primarily necessary in calculating protection against y-radiation. The method, tables and nomograms for calculating protection are based on mathematically strict ratios and are universal in nature, since they allow taking into account the diversity of problems of its design. The book is intended for physicists, radiobiologists, students and graduate students of technical universities and especially for design engineers and workers engaged in the processing of fissile materials or their use in various fields of science and technology. The book can also be useful to a wide range of people interested in radiation characteristics and protection against radiation from fission products.