Methods and systems for stabilizing spent fuel assemblies from sodium-cooled nuclear reactors using Zamak are described herein. It has been determined that there is a synergism between Zamak and sodium that allows Zamak to form thermally-conductive interface with the sodium-wetted surfaces of the fuel assemblies. In the method, one or more spent fuel assemblies are removed from the sodium coolant pool and placed in a protective sheath. The remaining volume of the sheath is then filled with liquid Zamak. To a certain extent Zamak will dissolve and alloy with sodium remaining on the fuel assemblies. Excess sodium that remains undissolved is displaced from the sheath by the Zamak fill. The Zamak is then cooled until solid and the sheath sealed. The resulting Zamak-stabilized spent fuel assembly is calculated to have sufficient internal thermal conductivity to allow it to be stored and transported without the need for liquid cooling.

A decontamination paste comprising at least one inorganic viscosifier selected from clays, at least one compound in the form of fibers and optionally further one or more optional components, the remainder being of solvent. A method for decontaminating a substrate made of a solid material using the paste, the substrate being contaminated by at least one contaminant species referred to as the labile contaminant species and/or by at least one contaminant species referred to as the surface contaminant species located on one of the surfaces thereof, and/or by at least one contaminant species referred to as the subsurface contaminating species located just below said surface, and/or by at least one contaminant species located under the surface in the depth of the substrate.

The invention relates to a method for producing a solid nanocomposite material comprising nanoparticles of a metal coordination polymer with ligands CN, said nanoparticles satisfying the formula [Alk.sup.+.sub.x]M.sup.n+[M′(CN).sub.m].sup.z− where Alk is an alkali metal, x is 1 or 2, M is a transition metal, n is 2 or 3, M′ is a transition metal, m is 6 or 8, and z is 3 or 4; said M.sup.n+ cations of the coordination polymer being bound by an organometallic bond or a coordination bond to an organic group R2 of an organic graft, and said organic graft furthermore being chemically attached, preferably by a covalent bond, to at least one surface of a solid support, by reaction of a group R1 of said graft with said surface.

The present invention relates to a method for treating waste material comprising organic components and low and/or medium level radioactive agents. The method comprises encapsulating the waste material into a matrix, gasifying the waste material at a temperature between 600 and 950° C. to form a gaseous fraction and a solid fraction comprising low and/or medium level radioactive agents and combustion residues of the organic components and encapsulating the solid fraction by a geopolymer matrix comprising metakaolin.

A composition to immobilize nuclear containing waste comprising at least one radioactive element or alloy of uranium, graphite, magnesium, and aluminum, and a method of using the same to immobilize the nuclear containing waste into a solid wasteform. The composition comprises at least one mineral phase forming element or compound for reacting with the at least one radioactive element or alloy. The composition further comprises at least one glass-forming element or compound to form a glass phase that will incorporate waste radioisotopes and impurities that do not react with the mineral phase forming element or compound.

A container for storage of molten material from an industrial facility, and method of manufacture thereof, is provided to maximize internal volume of the container while providing structural stability. The container includes walls having rounded convex-shaped edges at each wall junction. A first head is connected to the walls at a first end of the container, and a second head closes the second end of the container. The second head is connected to the walls at a second end of the container. Corners are defined at the intersection of the walls with the first head and second head at the first end and the second end respectively. A first flange is connected to the first head to receive molten material, and the first head is shaped as a tapered shoulder to smoothly transition from the first flange to the junction of the walls.

Composition, manufactures, and processes of making and using them, consisting essentially of a neutron absorbent, having a neutron absorption cross section greater than or equal to Boron comprising at least 19.7% of Boron-10 isotope, and a thermal conductor having a thermal conductivity of at least 10% of water thermal conductivity at 100 degrees C. at sea level, combined such that the particles have a density of at least 0.9982 g/mL and not more than 2.0 g/ml. The composition can be located for release responsive to a loss of normal heat sink event and/or a loss of normal coolant event in a quantity sufficient, to palliate the loss of the normal heat sink event and/or the loss of normal coolant event.

A container for storage of molten material from an industrial facility, and method of manufacture thereof, is provided to maximize internal volume of the container while providing structural stability. The container includes walls having rounded convex-shaped edges at each wall junction. A first head is connected to the walls at a first end of the container, and a second head closes the second end of the container. The second head is connected to the walls at a second end of the container. Corners are defined at the intersection of the walls with the first head and second head at the first end and the second end respectively. A first flange is connected to the first head to receive molten material, and the first head is shaped as a tapered shoulder to smoothly transition from the first flange to the junction of the walls.

The electromagnetic shielding of the inductor comprises a main field-concentrating shielding composed of vertical columns, and the columns are composed of ferromagnetic blocks separated by non-magnetic gaps which contribute to increasing the magnetic reluctance in order to strongly reduce the heat losses. The main shielding is supplemented by an outer conductive casing which confines the residual field that has escaped from the main shielding. The shielding is compact, the mass of ferromagnetic material to be used is modest, autonomous cooling of the main shielding is unnecessary and the electromagnetic coupling between the casing and the main shielding reduces or even eliminates the effects on the electrical characteristics of the equipment.

Methods and systems for stabilizing spent fuel assemblies from sodium-cooled nuclear reactors using Zamak are described herein. It has been determined that there is a synergism between Zamak and sodium that allows Zamak to form thermally-conductive interface with the sodium-wetted surfaces of the fuel assemblies. In the method, one or more spent fuel assemblies are removed from the sodium coolant pool and placed in a protective sheath. The remaining volume of the sheath is then filled with liquid Zamak. To a certain extent Zamak will dissolve and alloy with sodium remaining on the fuel assemblies. Excess sodium that remains undissolved is displaced from the sheath by the Zamak fill. The Zamak is then cooled until solid and the sheath sealed. The resulting Zamak-stabilized spent fuel assembly is calculated to have sufficient internal thermal conductivity to allow it to be stored and transported without the need for liquid cooling.