This reduces one of DFR’s major hazards as the two six metre deep concrete chambers are drained in preparation for removing the concrete and bitumen liner as the former reactor is pulled apart. The pond is a concrete vault similar to a swimming pool and the water provided shielding for workers from the radiation emitted by spent fuel placed in racks on the bottom. In one pond, only four inches of thick brown sludge remains, a cocktail of corrosion and remnants of historical pond storage material.
The clean up team used pressure washers to force the contaminated ‘mud’ through a dirt buster nozzle. This blends the sludge into a ‘soup like’ consistency which is then passed through a large filter containing twenty-seven cartridges. The cartridges capture the soup, and are then encapsulated in grout and stored in 200L waste drums.
You can read the full report here.