Chemical hazards for nuclear fuel cycle facilities

International audienceAccidents involving hazardous chemicals pose a significant threat to the population and the environment. Among nuclear facilities, this threat applies in particular to the fuel cycle facilities. These hazards are linked to the chemical form of the radioactive material itself, to the chemical processes implemented, and to the chemical reagents used. As a consequence, the activities related to hazardous chemicals are covered by a legal framework that, depending on the nature of the activity and the associated risks, aims to guarantee that, they will not be likely to be detrimental to safety, public health and environment. In the safety assessment of fuel cycle facilities, chemical hazards have to be looked at deeply. The French Nuclear Safety Authority (ASN) will present a summary of the main regulations involving dangerous chemicals in nuclear fuel cycle facilities that have to be taken into account in the safety demonstration. The latter must prove that the risks of an accident - radiological or not - and the scale of its consequences, given the current state of knowledge, practices and the vulnerability of the installation environment, are as low as possible under acceptable economic conditions. IRSN will describe three examples of safety assessment regarding chemical hazard: explosion hazards during the sintering stage of UOx and MOx fuel manufacturing processes, on-site transportation of uranium hexafluoride, and corrosion of fission product solution concentrator. One of these cases will be an example of the appliance of the graded approach to fuel cycle facility safety evaluation and one an example of ageing by corrosion