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.

Methods and systems for melting or augmenting a melt rate of material in a melter using electromagnetic radiation with a frequency between 0.9 GHz and 10 GHz. In some examples, a power and/or frequency of radiation used may be selected so as to control a temperature of a cold cap in the melter while maintaining emissions from the melter below a threshold level. In this manner, examples described herein may provide for efficient and safe melting and vitrification of radioactive wastes.

A method for treating a fluid waste, comprising adding one or more process additives to the fluid waste in an amount sufficient to change the wasteform chemistry is disclosed. The addition step may be chosen from adding a dispersant or a deflocculant an additive to decrease the reactive metal components, to bind fission products and decrease volatilization of toxic or radioactive elements or species during thermal treatment, or to target and react with the fine particle size component of the waste to decrease dusting and immobilize components in a durable phase. After mixing the fluid waste with the described additives the waste is eventually hot-isostatic pressing, to form a durable and stable waste form.

The present disclosure relates to a method for dehalogenation and vitrification of radioactive metal halide wastes. The dehalogenation method of radioactive metal halide wastes includes the following steps: mixing the radioactive metal halide wastes with oxalic acid, and performing a thermal treatment to remove halogens from the radioactive metal halide wastes. The vitrification method includes a following step: immobilizing the dehalogenated wastes treated by the dehalogenation method of radioactive metal halide wastes into a vitrified form by adding glass additives. The benefits of the method for dehalogenation and vitrification of radioactive metal halide wastes provided by the present disclosure include not only low dehalogenation temperature, high dehalogenation efficiency and high waste loading in the vitrified form, but also no new substances introduced after dehalogenation, which is easy to be integrated with the existing vitrification process. Therefore, the present disclosure shows a promising application.

A metal oxide barrier and a connecting method for solving the problems in which sectors of an existing cold crucible are connected by means of a mica plate and the mica plate is damaged due to arcing and the like and in which the sectors are strongly connected by means of the mica plate and thus are difficult to replace and maintain. A cold crucible, comprising a metal oxide barrier, according to the present invention can prevent arcing, enables reduction of damage on the edge part of a water cooling sector due to a molten material and thus enhances durability. Moreover, the metal oxide barrier can easily be replaced compared to an existing mica plate and thus enables easy maintenance and repair.

The present disclosure provides a solidifying method of a radionuclide. The solidifying method of the radionuclide includes operations of: providing a low melting point glass including Bi.sub.2O.sub.3, B.sub.2O.sub.3, ZnO and SiO.sub.2; providing a glass mixture mixing a mixture to be treated containing a hydroxide of radionuclide and BaSO.sub.4 and the low melting point glass; and heating the glass mixture.

The present invention provides solidified radioactive waste into which a titanium-containing adsorbent having a radioactive element adsorbed thereto is vitrified, the solidified radioactive waste being capable of confining a large amount of the titanium-containing adsorbent having a radioactive element adsorbed thereto, and furthermore elution of the radioactive element from the vitrified waste being suppressed. The method of the present application includes a step of heat-melting a mixture that includes a titanium-containing adsorbent having a radioactive element adsorbed thereto, a SiO.sub.2 source, and an M.sub.2O source (M represents an alkali metal element) to form vitrified waste. The titanium-containing adsorbent is preferably one or two or more kind such as silicotitanate, an alkali nonatitanate, and titanium hydroxide.

Dangerous, toxic, and/or radioactive volatiles are produced from nuclear fission, nuclear decay, and/or as a byproduct from vitrification of radioactive wastes. Such volatiles are treated during and after vitrification of the radioactive waste, to be converted into fixed-chemicals, that are retained in, on, and/or proximate to a cold-cap located vertically above vitrified melt. The cold-cap may have one or more volatile fixing additives (VFAs) for retaining the fixed-chemicals. The VFAs are located in and/or the cold-cap. The vitrification may occur within at least one human-made cavern. The human-made cavern may be located within a deep geologic rock formation. The deep geologic rock formation may be located at least 2,000 feet below a terrestrial surface of the Earth. The human-made cavern may be formed by first drilling a wellbore from the terrestrial surface to the deep geologic rock formation and then underreaming the wellbore into the deep geologic rock formation.

Composition, manufactures, and methods of making and using them, illustratively a process including the steps of: changing density of a composition including a neutron absorbent, the 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 coolant thermal conductivity at 100 degrees C. at sea level, combined into the particles that have a density of at least 0.9982 g/mL and not more than 2.0 g/ml, the altering carried out in association with nuclear fuel or nuclear waste in a cask that is not located in a nuclear reactor containment vessel, the cask being a nuclear fuel cask or a spent nuclear fuel cask, the changing carried out by relocating the composition by at least one of the sub steps comprising: (A) operating a hollow conduit connected to a reservoir to relocate at least some of the particles from a reservoir into the cask, and/or (B) altering a close pack formation of the particles by effectuating a change from a static coefficient of friction of the particles to a dynamic coefficient of friction of the particles, thereby redistributing the particles within the cask into an altered close pack formation, and/or (C) removing at least some of the particles from the cask into the reservoir.

Provided is an induction heating device with which discharging can be easily avoided even when a large electric current is used. The induction heating device comprises a high-frequency power supply provided with a connection portion for an alternating-current power supply, and a heating coil portion connected to the high-frequency power supply. In the heating coil portion, a plurality of coils include n coils surrounding a cavity portion in a plane, wherein the plurality of coils are mutually connected in series via one of a plurality of capacitors.