(i) The justification of the practice.
(ii) The optimization of radiation protection.
(iii) The limits of the individual dos equivalent.
This report is concerned primarily with the second of these components of te system of dose limitation, the optimization of radiation protection, and with the rationale and techniques to establish what is reasonably achievable in the control of radiation exposures. A wide range of techniques is available to optimize radiation protection. Some of these techniques are drawn from operational research, some from economics and some from engineering. The use of a given technique implies, explicitly or implicitly, value judgements about the possible objectives of optimization. Techniques for use in the optimization of radiation protection include, but are not confined to, the procedures based on cost-benefit analysis and it is these procedures that are discussed in detail in this report. It is important to recognize that other techniques, some quantitative, some more qualitative, may also be used in the optimization of radiation protection.