Improvement of filtration and purification functions at nuclear units of EDF's park

The purification of nuclear power plant circuits is ensured by a set of filters and resins. This purification process plays a key role in dosimetry abatement. Filters have a preventive and a curative action as they collect particulates before and after their activation. Resins ensure the retention of soluble elements penalizing for the corrosion of circuits and for the dosimetry. This paper presents the improvement works in progress for the filtering and purification functions in the framework of the MTS 2 project (mastery of the source term 2). These works concern the improvement of the processes in use today as well as the search for innovative solutions: optimization of purification, exploitation feedback analysis, recommendations for filters and resins, qualification and standardization of filters. The implementation of national markets has permitted to better characterize the filters and resins used and have led to a significant reduction of purchase costs. The relations established with suppliers allow also to involve them in the problems encountered at reactor units. (J.S.)