A research facility in Ontario that stores used nuclear fuel rods by shielding them with water experienced contamination inside the storage pools of tritiated heavy water.
The contaminated water needs to be replaced with fresh water, while maintaining a steady full water level within the rod bay, and providing a system which would negate the mixing of the two waters.
A solution was provided to remove and replace the entire volume of water, while maintaining a steady water level within the rod bay with fresh deionized water. In order to swap these volumes, a feed and bleed process would be implemented. In order to discourage the mixing of the two waters, a thermal stratification method would be used, essentially fresh cool water added to the bottom of the pools while contaminated hot water was bled off the top.
This system meant that the client was not required to remove the used fuel from the pools to replace the water, translating to savings in both dollars and time. Shielding and handling the used fuel would be exhaustive with regard to monetary and scheduling issues. Furthermore, because of Promation’s test pool located at their facility in Oakville, this system was fully tested beforehand in-house.