Sources of Gamma Radiation in a Reactor Core

In a thermal reactor the gamma ray sources of importance for shielding calculations and related aspects are (1) fission, (2) decay of fission products, (3) capture processes in fuel, poison and other materials, (4) inelastic scattering in the fuel and (5) decay of capture products. The energy release and the gamma ray spectra of these sources have been compiled or estimated from the latest information available, and the results are presented in a general way to permit application to any thermal reactor, fuelled with a mixture of ²³⁵U and ²³⁸U. As an example the total spectrum and the spectrum of radiation escaping from a fuel rod in the Swedish R3-reactor are presented.