Maintenance and repair tools of the 900 MW PWR units in France

EDF and FRAMATOME have developed special tools and, repair and maintenance procedures to decrease the unavailability of the PWR units and the dosimetry of the personnel of maintenance. This report presents the solution adopted to face the problem of replacement of the internal upper structure pins of 21 units: 1) study and realisation of important industrial means; 2) development of a strategy: the pin replacement is separated from the guide tube replacement by the creation of a pin replacement shop, and, as often as it is possible, the ''AQUARIUM'' method allows to replace the guide-tubes with the aid of a mobile pool called AQUARIUM outside the critical way of shutdown