Fire risk at the T2 workshop in the UP3 plant at La Hague

At the T2 workshop in the UP3 plant at La Hague, fission products are extracted and uranium is separated from plutonium using a tributyl phosphate type solvent. In view of the high level of activity and the presence of inflammable products, this workshop has been the subject of a special fire risk study. Two approaches to examining this risk were used, taking into account the accessibility or inaccessibility of the units and rooms: (1) for accessible rooms, analysis led to envisaging conventional solutions for detecting and extinguishing a fire; and (2) for areas which become inaccessible once the plant is in operation zone 4, an extremely detailed analysis was made of the probability of a fire breaking out, as well as the level of activity which could be released from the units to the outside environment. Further to this analysis, various steps were selected for producing the equipment contained in these units: (a) to prevent the presence of inflammable liquids in the cells; and (b) to prevent the presence of a 'spark' likely to start a fire. All the steps and precautions taken in zone 4 units reduce the probability of a fire breaking out to a level such that it becomes extremely unlikely. The previous analysis was supplemented by a few rather more conventional measures. For those units (zone 4) containing only non-flammable liquids (aqueous solutions) analysis has shown that no particular fire protection equipment is required. (author). 1 fig