Reconditioning of the TRIGA Mark III reactor

The paper describes the activities carried out to recondition the TRIGA Mark III reactor at the Mexican Nuclear Centre, namely repair of its containment system, maintenance of its operational systems, and the obtaining of a licence for the facility and its operating staff. The process of initially obtaining the operating licence from the regulatory authority was affected by the existence of water leaks in the pool which were detected in March 1985 and were caused by corrosion in the reactor containment system. Reconditioning began with a series of activities aimed at locating, delimiting and repairing the areas damaged by corrosion and involved establishing criteria for selecting the most appropriate inspection, testing and repair methods. In order to obtain the operating licence, it was necessary to comply with various requirements laid down by the regulatory body. The most important requirements included: (a) repair of the reactor pool; (b) maintenance of its operational systems; (c) preparation and implementation of the Quality Control Programme; (d) updating of the Safety Report; (e) updating and preparation of operating, repair, radiation safety, emergency and administrative procedures; and (f) training of operating staff. In addition, the paper describes the work carried out at this reactor to widen its field of research and range of utilization. This work includes the reconditioning of a neutron diffractometer, the design and construction of a neutron diffractometer to determine the textures of materials, and the analysis of a new mixed core configuration based on fuels with 20% and 70% 235U enrichment. (author). 7 refs