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.

The invention relates to a combination of containers intended to discharge radioactive substances into the earth's magma by pouring them into lava lakes, and to a method for using these containers. The radioactive substances are preferably placed in ovoid waste containers that are loaded into a transport container and discharged therewith into a lava lake. The transport container decomposes by melting following a first immersion at a given depth and releases the waste containers, which continue to move downwards.

A method for decontaminating a metal surface exposed to radioactive liquid or gas during operation of a nuclear facility comprises an oxidation step wherein a metal oxide layer on the metal surface is contacted with an aqueous oxidation solution comprising a permanganate oxidant for converting chromium into a Cr(VI) compound and dissolving the Cr(VI) compound in the oxidation solution; and a first cleaning step wherein the oxidation solution containing the Cr(VI) compound is directly passed over an anion exchange material and the Cr(VI) compound is immobilized on the anion exchange material. The method provides for substantial savings of radioactive waste and produces chelate-free waste.

A suctionable gel for eliminating a contaminating species contained in an organic layer on the surface of a material, consisting of a colloidal solution comprising, preferably consisting of: 1 wt % to 25 wt %, preferably 5 wt % to 20 wt % based on the total weight of the gel, of at least one inorganic viscosifying agent; 13 wt % to 99 wt %, preferably 80 wt % to 95 wt % based on the total weight of the gel, of an organic solvent selected among the terpenes and the mixtures thereof; optionally, 0.01 wt % to 10 wt %, based on the total weight of the gel, of at least one dye and/or pigment; optionally 0.1 wt % to 2 wt %, based on the total weight of the gel, of at least one surfactant. The disclosure further relates to a decontamination method using the gel.

The invention relates to a method of decontaminating a metal surface, wherein the metal surface is located on a component within a nuclear plant, in particular within the cooling system of a nuclear power plant, and is covered with a metal oxide layer containing radioactive substances, and wherein the method comprises a decontamination step in which a metal oxide layer pretreated in an oxidation step is contacted with an aqueous solution of an organic acid to dissolve the metal oxide layer, forming a decontamination solution containing the organic acid as well as metal ions and the radioactive substances, and wherein the decontamination solution is passed over an ion exchanger to immobilize the metal ions and the radioactive substances. An oxidant selected from the group consisting of oxygen, air, hydrogen peroxide and ozone is dosed into the decontamination solution to control the dissolution rate of the metal oxide layer. The method is particularly suitable for large-scale system decontamination and ensures high process stability.

Device for deactivating radioactive elements comprising a loading-unloading manipulator, a process chamber with a lid with a round turn-around table located inside, a waste disposal container and an exhaust ventilation unit. The process chamber is equipped with a remote handling unit mounted on its outer part, a device for a dust-free abrasive blast cleaning, a waterjet cutting unit, connected through a leak-tight installed hoses in the process chamber walls, an abrasive and slurry collection unit and at least one device for radiation control, located inside the process chamber, the solid and liquid waste separation unit and discharge liquid waste. The process chamber is equipped with a chemical-radiation-shock proof sound-absorbing coating, and the remote control unit is connected with the device for a dust-free abrasive blast cleaning, waterjet cutting unit, abrasive and slurry collection device, exhaust ventilation unit, the process chamber lid, the radiation unit and the waste separation unit.

Apparatus for treating a source of radioactive emission, the apparatus including at least one reflecting means adapted to be in proximity to the source for receipt of the radioactive emission and to at least partially reflect received emission towards the source, thereby effecting reduction of the radioactive emission from the source.

Apparatus for treating a source of radioactive emission, the apparatus including at least one reflecting means adapted to be in proximity to the source for receipt of the radioactive emission and to at least partially reflect received emission towards the source, thereby effecting reduction of the radioactive emission from the source.

Provided are a chemical decontamination method and a chemical decontamination apparatus capable of preventing deterioration of a metal ion exchange resin and performing decontamination at a low cost in a short time.

The chemical decontamination method of the invention includes: a reduction decontamination step of supplying a reduction decontamination solution to a decontamination target portion and performing reduction decontamination on a surface of a member constituting the decontamination target portion; a hydrogen peroxide decomposition step of decomposing hydrogen peroxide contained in the reduction decontamination solution after the reduction decontamination step; and a metal ion removing step of removing a metal ion contained in the reduction decontamination solution after the hydrogen peroxide decomposition step.

The present invention relates to a cleaning composition for the decontamination of surfaces, in particular radioactive surfaces, and the related decontamination method.