METHOD OF DEACTIVATING LARGE UNDERGROUND STORAGE WITH CONCENTRATED SALT PRECIPITATES OF HIGHLY ACTIVE LIQUID RADIOACTIVE WASTES Russian patent published in 2010 - IPC G21F9/00 

FIELD: physics, nuclear.

SUBSTANCE: invention relates to nuclear power engineering and pertains to deactivation for long-term storage in large underground storages with concentrated salt precipitates of highly active liquid radioactive wastes (LRW). In order to fill the storage with preservative concrete, underground water in the area near the storage is lowered below the level of the lower edge of roof of the storage. Wells in which casing pipes are put are drilled through fill-up ground and the roof of the storage. Further, vertically moveable concrete delivery pipes are put into the wells and standard access holes, through which radiation-resistant preservative concrete is laid into the storage in successive layers with an interval of 7-10 days between layers, where the said preservative concrete has radiation resistance of not less than 6000 Mrad. The end of the concrete delivery pipe must be sunk into the concrete being laid down at a depth which ensures continuity and quality of the laying process. Before laying each layer, a volume of liquid radioactive wastes inside the storage equal to the volume of the layer of preservative concrete being laid down is pumped out. The thickness of the laid down layer is determined from the results of heat calculations on release of amount of heat during cement hydration, for which temperature of the solidified block must not exceed 20-25°C.

EFFECT: reliable barrier immobilisation during deactivation of large storages with highly active liquid radioactive wastes.

5 cl, 6 dwg