Managing anticipated collective doses

Limitation of exposure to ionizing radiations is based on the recommendations of the International Commission on Radiological Protection and on the observance of certain rules, instructions and operating modes. Planning for anticipated collective doses, based on standards which are kept up to date as the characteristics of the work evolve, is a further useful element which may be added to existing arrangements. Analysis of results for operations rendered analogous by the introduction of equivalence parameters reveals the effectiveness of radioprotection and suggests such modifications in methods of work and measures of protection as may be required. Each year the production services are consulted about their work programmes (regular or occasional operations, work sites envisaged). The most important factors taken into account are the radioactive characteristics of the materials handled, the number of man-days involved or of pieces handled, or the number of days of operation for an installation. In this way equalizations are performed on the basis of known values derived from previous experience, and from these it is possible to establish standards and accordingly to make predictions. If no reference is available, an estimate is nevertheless made as a forecast. The immediate result of all this is the delineation of provisions designed to mitigate certain inadequacies of protection in good time - or, where appropriate, to make existing measures less rigorous. In some cases, methods of work may be modified. Operations deemed inessential may be deferred or even eliminated. At the end of a given period (one year, for example), predictions are compared with the facts that have actually emerged and explanations are sought for the discrepancies observed. The primary data inserted in the model are thus progressively adjusted. The main purpose of the method described here is to add a further, complementary element to the prevention measures already available and thus to contribute to limiting the exposure of personnel to ionizing radiations. (author)