A chemical decontamination method capable of improving the decontamination efficiency of chemical decontamination of a steam dryer in the RPV is provided. In particular, the decontamination method includes feeding a chemical decontamination aqueous solution into a reactor pressure vessel in which a steam dryer is arranged, and after chemical decontamination of the steam dryer, the water level of the chemical decontamination aqueous solution existing in the reactor pressure vessel is lowered to a first water level below the lower end of the steam dryer.

A chemical decontamination method capable of improving the decontamination efficiency of chemical decontamination of a steam dryer in the RPV is provided. In particular, the decontamination method includes feeding a chemical decontamination aqueous solution into a reactor pressure vessel in which a steam dryer is arranged, and after chemical decontamination of the steam dryer, the water level of the chemical decontamination aqueous solution existing in the reactor pressure vessel is lowered to a first water level below the lower end of the steam dryer.

A method for decommissioning a heavy water reactor facility includes: removing the plurality of guide tubes from a plurality of through-holes; installing a plurality of shielding stoppers in the plurality of through-holes; removing the shielding stopper installed in one through-hole of the plurality of through-holes, and inserting a cutting device into a lower portion of the reactivity mechanism deck through the one through-hole to cut a connection portion between the reactivity mechanism deck and the calandria vault by using the cutting device; and separating the reactivity mechanism deck from the calandria vault.

A hazardous material storage repository includes a drillhole extending into the Earth and including an entry. The drillhole includes a vertical drillhole portion, a transition drillhole portion coupled to the vertical drillhole portion, and a hazardous material storage drillhole portion coupled to the transition drillhole portion. The hazardous material storage drillhole portion is located below a self-healing geological formation and is vertically isolated, by the self-healing geological formation, from a zone that comprises mobile water. The repository includes a storage canister positioned in the hazardous material storage drillhole portion and sized to fit from the drillhole entry through the vertical drillhole portion, the transition drillhole portion, and into the hazardous material storage drillhole portion. The storage canister includes an inner cavity sized to enclose hazardous material.

A hazardous material storage repository includes a drillhole extending into the Earth and including an entry. The drillhole includes a vertical drillhole portion, a transition drillhole portion coupled to the vertical drillhole portion, and a hazardous material storage drillhole portion coupled to the transition drillhole portion. The hazardous material storage drillhole portion is located below a self-healing geological formation and is vertically isolated, by the self-healing geological formation, from a zone that comprises mobile water. The repository includes a storage canister positioned in the hazardous material storage drillhole portion and sized to fit from the drillhole entry through the vertical drillhole portion, the transition drillhole portion, and into the hazardous material storage drillhole portion. The storage canister includes an inner cavity sized to enclose hazardous material.

A hazardous material storage repository includes a drillhole extending into the Earth and including an entry. The drillhole includes a vertical drillhole portion, a transition drillhole portion coupled to the vertical drillhole portion, and a hazardous material storage drillhole portion coupled to the transition drillhole portion. The hazardous material storage drillhole portion is located below a self-healing geological formation and is vertically isolated, by the self-healing geological formation, from a zone that comprises mobile water. The repository includes a storage canister positioned in the hazardous material storage drillhole portion and sized to fit from the drillhole entry through the vertical drillhole portion, the transition drillhole portion, and into the hazardous material storage drillhole portion. The storage canister includes an inner cavity sized to enclose hazardous material.

A hazardous material storage repository includes a drillhole extending into the Earth and including an entry. The drillhole includes a vertical drillhole portion, a transition drillhole portion coupled to the vertical drillhole portion, and a hazardous material storage drillhole portion coupled to the transition drillhole portion. The hazardous material storage drillhole portion is located below a self-healing geological formation and is vertically isolated, by the self-healing geological formation, from a zone that comprises mobile water. The repository includes a storage canister positioned in the hazardous material storage drillhole portion and sized to fit from the drillhole entry through the vertical drillhole portion, the transition drillhole portion, and into the hazardous material storage drillhole portion. The storage canister includes an inner cavity sized to enclose hazardous material.

An apparatus for decommissioning heavy-water reactor facilities includes a shielding device including a drawing-out space that is mounted on the reactivity mechanism deck and communicates with one through-hole among the plurality of through-holes, a separating device that is inserted into the inside of one of the plurality of guide tubes through the drawing-out space and the one through-hole and cuts an end portion of the one guide tube connected to the calandria, and a drawing-out device that is inserted into the inside of the one guide tube through the drawing-out space and the one through-hole and supports the end portion of the one guide tube to draw out the one guide tube into the inside of the drawing-out space through the one through-hole.

Apparatus for drying Spent Ion-Exchange Resins (SIER), which can intensify the SIER drying process, reduce power consumption, and accelerate discharge of SIER when the drying process is completed. The apparatus comprises a sealed cylindrical body, and a blow-down choke installed in an upper part of the sealed cylindrical body and a nozzle to feed the spent ion-exchange resins is installed inside the body, and a nozzle to retrieve dried ion-exchange resins is installed in its bottom part and equipped with a locking device. An external heater is provided for the body, and a drive shaft that is installed in alignment inside the body, capable of rotation, and equipped with a stirrer. A lower part of the drive shaft with lower screw winding is installed in alignment inside the nozzle to retrieve dried ion-exchange resins. The nozzle to retrieve dried ion-exchange resins is equipped with a water draining device.

An apparatus for treating waste of a nuclear reactor pressure vessel includes: a suction unit inserted into the nuclear reactor pressure vessel through a plurality of through-pipes passing through a lower portion of the nuclear reactor pressure vessel to suck waste inside the nuclear reactor pressure vessel; a waste treatment part connected to the suction unit to treat the waste; and a lower collection part connected to the waste treatment part to be positioned under the nuclear reactor pressure vessel with the suction unit therebetween.