Corrosion problems in the aluminum tank of the reactor of Mexico

The contention developed a leak that was found on March 15th 1985 in a routine inspection to the exposure room. The maximum water leak reached almost 5 liters per hour, it started to diminish until it disappeared completely two months later. It is believed that the holes were blocked by particles in suspension that were introduced to the primary system during the leaking tests. Immediately after the finding of the leak an inspection, testing and repair program was established. Hydrostatic tests to the primary cooling system and cooling system of the exposure room piping showed that the problem was the aluminum liner and not the piping. In order to have the possibility of inspecting the walls of the tank, the pool was drained from its 7.49 m of water down to 3.6 m of depth. At this point the reactor operation stopped and the inspection work started. Previously gamma radiation doses were evaluated using TLD crystals and was determined that 3.6 m of water column gave 0.1 mR/hr of gamma radiation doses at the surface. (orig./HP)