Congress asked the National Academies to review the civilian uses of radiation sources that contain radionuclides and the potential replacements for sources that pose a high risk to public health or safety in the event of an accident or attack. The Academies committee made findings and recommendations on options for implementing the identified replacements taking into account the hazards and risks and the feasibility of replacements. While the study did not include a detailed cost-benefit analysis, it did examine potential government provided incentives for facilitating the introduction of replacements into the market place.