This Safety Guide provides recommendations on the use of radioactive sources and radiation generators in well logging, including in the manufacture, calibration and maintenance of well logging tools. It provides recommendations on radiation protection and safety for the storage, use and transport of such radiation sources. The guidance in this publication is aimed primarily at operating organizations that are authorized to undertake well logging with radiation sources, as well as their employees and radiation protection officers. The guidance will also be of interest to regulatory bodies, and to designers, manufacturers, suppliers, and maintenance and servicing organizations of well logging equipment that contains radiation sources.