A migration prevention system for radioactive wastewater from an underground nuclear power plant. The underground nuclear power plant includes a nuclear island including an underground cavern group including a reactor cavity and auxiliary cavities. The migration prevention system includes a protective layer coating the reactor cavity and an impermeable layer surrounding the nuclear island. The protective layer includes an inner liner, a drainage layer, and a filling layer of rock fractures in that order. The inner liner is configured to prevent exosmosis of the radioactive wastewater of the reactor cavity. The drainage layer is configured to gather and drain seepage water. The impermeable layer is disposed in the periphery of the underground cavern group including the reactor cavity and the auxiliary cavities, and is configured to isolate the underground cavern group from natural underground water.

A container for radioactive inventory has an end wall, a side wall, and a container lid that form a closed chamber for the radioactive inventory. A plastically deformable layer is provided between the container lid and the inventory and is of such a composition that, in the event of an impact of the inventory against the container lid, at least a majority of the impact forces are uniformly distributable over at least a majority of a surface of the plastically deformable layer.

A container holds radioactive material. A sub-criticality controller protects the radioactive material from reaching a criticality from contact with the water. The sub-criticality controller includes a metallic composition having at least one metal component and at least one borate component bonded to the at least one metal component. The metallic composition forms a new borate that absorbs neutrons when the metallic composition contacts water in the case of an incident.

A container holds radioactive material. A sub-criticality controller protects the radioactive material from reaching a criticality from contact with the water. The sub-criticality controller includes a metallic composition having at least one metal component and at least one borate component bonded to the at least one metal component. The metallic composition forms a new borate that absorbs neutrons when the metallic composition contacts water in the case of an incident.

A radioactive waste immobilization apparatus for immobilizing radioactive waste loaded in a high-integrity container to enhance the storage safety of the radioactive waste and a radioactive waste immobilization method using the same are disclosed. A radioactive waste immobilization apparatus according to an embodiment of the present invention, which is for immobilizing the upper part of radioactive waste loaded in a high-integrity container to prevent the possibility of the radioactive waste leaking to the outside, includes: a polymer resin injection unit forming a polymer resin layer by injecting an immobilizing polymer resin onto the radioactive waste loaded in the high-integrity container; a polymer resin sensing unit adjusting an injection amount of the polymer resin by measuring a thickness of the polymer resin layer; and a light curing unit curing the polymer resin layer.

A radioactive waste immobilization apparatus for immobilizing radioactive waste loaded in a high-integrity container to enhance the storage safety of the radioactive waste and a radioactive waste immobilization method using the same are disclosed. A radioactive waste immobilization apparatus according to an embodiment of the present invention, which is for immobilizing the upper part of radioactive waste loaded in a high-integrity container to prevent the possibility of the radioactive waste leaking to the outside, includes: a polymer resin injection unit forming a polymer resin layer by injecting an immobilizing polymer resin onto the radioactive waste loaded in the high-integrity container; a polymer resin sensing unit adjusting an injection amount of the polymer resin by measuring a thickness of the polymer resin layer; and a light curing unit curing the polymer resin layer.

A liquid waste removal system for removing liquid waste remaining within a concrete drum that houses a container filled with concentrated waste liquid is disclosed. A liquid waste removal system according to an embodiment of the present invention, which is for removing liquid waste remaining inside a concrete drum that houses a container filled with radioactive waste, includes: a fixed support supporting and fixing the concrete drum; and a transfer pipe penetrating one side of the concrete drum and discharging the liquid waste out of the concrete drum.

A liquid waste removal system for removing liquid waste remaining within a concrete drum that houses a container filled with concentrated waste liquid is disclosed. A liquid waste removal system according to an embodiment of the present invention, which is for removing liquid waste remaining inside a concrete drum that houses a container filled with radioactive waste, includes: a fixed support supporting and fixing the concrete drum; and a transfer pipe penetrating one side of the concrete drum and discharging the liquid waste out of the concrete drum.

A radioactive sodium destruction facility includes a tank for storing liquid metallic sodium, located at a first level; a reaction vessel containing an aqueous solution; a sodium feed circuit comprising a sodium circulation member located at a second level higher than the first level, the circulation member having a suction in fluid communication with the tank and a discharge in fluid communication with the reaction vessel; an inert gas supply unit configured to supply the tank; a controller driving the sodium circulation member; and an inert gas supply unit configured to supply the tank; and a controller driving the supply unit to control a gas pressure in the tank, such that a pressure at the suction of the sodium circulation member is maintained within a predetermined range.

A radioactive sodium destruction facility includes a tank for storing liquid metallic sodium, located at a first level; a reaction vessel containing an aqueous solution; a sodium feed circuit comprising a sodium circulation member located at a second level higher than the first level, the circulation member having a suction in fluid communication with the tank and a discharge in fluid communication with the reaction vessel; an inert gas supply unit configured to supply the tank; a controller driving the sodium circulation member; and an inert gas supply unit configured to supply the tank; and a controller driving the supply unit to control a gas pressure in the tank, such that a pressure at the suction of the sodium circulation member is maintained within a predetermined range.