The ICRP, in its 1990 Recommendations, divided situations affecting radiation exposure of individuals into two broad categories: practices and intervention. The basic principles of radiation protection are applied to these categories in different ways. In the case of practices, the principles are applied to the addition of radiation risk caused by the introduction or modification of practices, whilst for intervention they are applied to the subtraction or reduction of pre-existing radiation exposure. Radiation exposure which might result from the introduction of a practice is also divided into two broad categories: normal exposure and potential exposure. Normal exposure is that exposure which can reasonably be expected to occur, i.e., the exposure is predicted to occur with a probability of one or near one, independent of the time when the exposure occurs. Potential exposure is exposure that, while not certain to occur, can be anticipated as a result of introducing or modifying a practice and to which a probability of occurrence can be assigned. The purpose of this report is to elaborate upon the principles and objectives of ICRP recommendations as they relate to potential exposure; explain basic concepts, terminology and methodologies associated with application of the recommendations; and to provide general guidance on its practical application. The report is intended to provide a basis for the preparation of more detailed guidance related to specific practices.
Introduction. Basic Concepts. Risk. Probability. Dose response relationship. The Basis of Radiation Safety. Aims. Source- and individual-related assessments. Basic principles. Protection from Potential Exposure: Practical Applications. Justification of practice. Optimisation of radiation safety. Individual health risk limitation. The role of prevention and mitigation. Assessment techniques. Application in practice. Exclusion of scenarios and event sequences. Exemption of scenarios and event sequences. Regulation in the context of potential exposures. References. 1 illus, 12 lit refs.