[en] The main properties and characteristics of radiophotoluminescent glasses of current use at the French Atomic Energy Commission for the dosimetry of γ radiation and thermal neutrons are described: composition, response to exposure, response to the various radiations. The effects of experimental conditions of utilization are examined and some examples of application are given

[en] The characteristics and nuisances of radioactive waste depend on the nature of the radionuclides, the substrate materials, the nature of the strength of links. The external or internal exposure hazards (ingestion, inhalation) of persons are reduced by the use of barriers. The building of the storage according to the period and activity of the radionuclides is examined. Activity limits must be set according to the risks of irradiation or contamination of the environment

[en] The high temperature incineration of radioactive waste gives flue gases with high temperature which can be contaminated with radionuclides and chemical products. It is therefore necessary to choose a technique decreasing these contaminations, to treat and filter the gases, to control effluents contamination

[en] Equipment described in the claim is designed for selective detection of alpha particles emitted by the mixture of radium A and radium C'. It is primarily intended for mine contamination control. Air is pumped through a filter collecting radioactive aerosols. Two collimators are placed opposite the filter. Cellulose nitrate is used as the detector. Polycarbonate foils serving the filtration of alpha radiation 6 and 25 microns in thickness, respectively, are placed forward of the detectors. The content of radium A and radium C' is calculated from the readings of the detectors. (Ha)

[en] A portable instrument of the pocket type designed primarily for monitoring atmospheric contamination in uranium mines by selectively detecting the α-particles emitted simultaneously by the daughter products of radon, namely radium A and radium C' is described. The instrument comprises in combination a tube containing a suction fan for drawing external air through a filter which retains the α-emitting aerosols, a detector in which the α-particles corresponding to the respective energies of the α-emissions of radium A and of radium C' are detected separately, and two collimators placed between the filter and the detector

[en] The long term safety of a nuclear waste repository relies on the evaluation of the doses which could be transferred to man in the future. This implies a detailed knowledge of the medium where the waste will be confined, the identification of the basic phenomena which govern the migration of the radionuclides and the investigation of all possible scenarios that may affect the integrity of the barriers between the waste and the biosphere. Inside the Institute of protection and nuclear safety of the French Atomic Energy Commission (CEA/IPSN), the Department of the Safety Analysis (DAS) is currently developing a methodology for assessing the safety of future geological waste repositories, and is in charge of the modelling development, while the Department of Technical Protection (DPT) is in charge of the geological experimental studies. Both aspects of this program are presented. The methodology for risk assessment stresses the needs for coordination between data acquisition and model development which should result in the obtention of an efficient tool for safety evaluation. Progress needs to be made in source and geosphere modelling. Much more sophisticated models could be used than the ones which is described; however sensitivity analysis will determine the level of sophistication which is necessary to implement. Participation to international validation programs are also very important for gaining confidence in the approaches which have been chosen

[en] This paper describes a radiological assessment of a shallow land burial site. The results of the assessment show that there are many potential sites which would meet safety regulations. (author)

[en] Present regulations are not adequate for recycling or disposal of large quantities of waste from dismantled nuclear installations. Exemption limits may be set for particular kinds of materials normally produced during operation and dismantling. Exemption activity limits are based on dose levels and take into account the total mass of expected waste and all the possibilities of exposure. Case-by-case authorization procedures would only then be necessary for materials not treated by the exemption procedure or for materials with activities higher than the exemption limits. Exemption limits for steel have been evaluated for some radionuclides. This evaluation is based on usual industrial practices and working condition measurements and leads to mass and surface activity limits

No abstract available

[en] During dismantling operations of nuclear facilities radioctive and non radioactive wastes are produced. The distinction between both kinds of wastes is not easy. In each dismantling operation special care and rules are defined for the separation of wastes. Each case must be separately studied. The volume and the surface activites are analyzed. Part of the wastes had been disposed in a public environment. The regulations, the international recommendations, thetheoretical and experimental investigations in this field are presented. A regulation principle and examples of radioactivity limits, on the basis of international recommendations, are provided. Those limits are calculated from individual radiation dose that may reach human beings