This disclosure describes nuclear fuel salts usable in certain molten salt reactor designs and related systems and methods. Binary, ternary and quaternary chloride fuel salts of uranium, as well as other fissionable elements, are described. In addition, fuel salts of UCl.sub.xF.sub.y are disclosed as well as bromide fuel salts. This disclosure also presents methods and systems for manufacturing such fuel salts, for creating salts that reduce corrosion of the reactor components and for creating fuel salts that are not suitable for weapons applications.

This invention generally concerns radioactive decontamination of deposits on components in a nuclear power plant and is specifically concerned with improved compositions, systems and methods for disrupting, dissolving, removing and reducing at ambient temperature radionuclides formed on the primary side surfaces of components in a pressurized water reactor and the internal components of a boiling water reactor. The methods include identifying the structure, taking the structure out of operational service, contacting the structure with an aqueous solution (e.g., a recirculating flow or static immersion), and adding an effective amount of elemental metal in solid form to the aqueous solution.

A photocatalyst injection system including: a reactor primary system coolant collection section collecting a reactor primary system coolant containing a noble metal or noble metal ion from a reactor primary system; a photocatalyst addition section adding a photocatalyst to the collected reactor primary system coolant; an ultraviolet irradiation section irradiating, with ultraviolet rays, the coolant to which the photocatalyst has been added for producing, in the coolant, a noble metal-carrying photocatalyst in which the noble metal is carried on a surface of the photocatalyst; and a noble metal-carrying photocatalyst injection section injecting the coolant containing the noble metal-carrying photocatalyst into the reactor primary system.

A photocatalyst injection system including: a reactor primary system coolant collection section collecting a reactor primary system coolant containing a noble metal or noble metal ion from a reactor primary system; a photocatalyst addition section adding a photocatalyst to the collected reactor primary system coolant; an ultraviolet irradiation section irradiating, with ultraviolet rays, the coolant to which the photocatalyst has been added for producing, in the coolant, a noble metal-carrying photocatalyst in which the noble metal is carried on a surface of the photocatalyst; and a noble metal-carrying photocatalyst injection section injecting the coolant containing the noble metal-carrying photocatalyst into the reactor primary system.

A method of determining and quantifying the presence and concentration of regulated radionuclides present in filter material used to remove radionuclide contaminants from the cooling water of a nuclear reactor. Multiple samples of the reactor cooling water are taken and the presence and concentration of directly measurable fission and activation produced radionuclides are determined through gamma spectroscopy. The release rate of radioactivity from the reactor as a function of the removal rate of the filter material is determined at equilibrium. The presence and the concentration of the indirectly measured fission regulated radionuclides are determined as a function of release rates of the directly measurable fission produced isotopes.

A method of determining and quantifying the presence and concentration of regulated radionuclides present in filter material used to remove radionuclide contaminants from the cooling water of a nuclear reactor. Multiple samples of the reactor cooling water are taken and the presence and concentration of directly measurable fission and activation produced radionuclides are determined through gamma spectroscopy. The release rate of radioactivity from the reactor as a function of the removal rate of the filter material is determined at equilibrium. The presence and the concentration of the indirectly measured fission regulated radionuclides are determined as a function of release rates of the directly measurable fission produced isotopes.

The invention describes a filtering device configured to be arranged inside a fluid to be filtered and comprising at least one main filter and a filter holder supporting the main filter. The filtering device is configured to be moved inside the fluid, in such a way that when the filtering device is moved in a first movement direction, at least one part of the fluid passes through the main filter in a first filtering direction. The filtering device is configured in such a way as to prevent the fluid from passing through the main filter in a second filtering direction opposite to the first filtering direction when the filtering device is moved in a second movement direction opposite to the first movement direction. The invention also relates to a system including such a device and to methods using such a device.

The invention describes a filtering device configured to be arranged inside a fluid to be filtered and comprising at least one main filter and a filter holder supporting the main filter. The filtering device is configured to be moved inside the fluid, in such a way that when the filtering device is moved in a first movement direction, at least one part of the fluid passes through the main filter in a first filtering direction. The filtering device is configured in such a way as to prevent the fluid from passing through the main filter in a second filtering direction opposite to the first filtering direction when the filtering device is moved in a second movement direction opposite to the first movement direction. The invention also relates to a system including such a device and to methods using such a device.

In a debris trap that may be used in an Emergency Core Cooling System of a nuclear power plant, the filter media is arranged to define both filtration and bypass flowpaths that are in fluid communication with one another. At least initially, each of the filtration and bypass flowpaths are open, and the filtration and bypass flowpaths have relatively low and relatively high head loss, respectively. The debris trap is operative so that flow through the debris trap may passively, and typically gradually, transition from the filtration flowpaths to the bypass flowpath in response to the filter media collecting increasing amounts of debris. More specifically, initially substantially all of the flow may be through the filtration flowpaths, and thereafter the filtration flowpaths may become substantially obstructed so that substantially all of the flow is through the bypass flowpath.

In a debris trap that may be used in an Emergency Core Cooling System of a nuclear power plant, the filter media is arranged to define both filtration and bypass flowpaths that are in fluid communication with one another. At least initially, each of the filtration and bypass flowpaths are open, and the filtration and bypass flowpaths have relatively low and relatively high head loss, respectively. The debris trap is operative so that flow through the debris trap may passively, and typically gradually, transition from the filtration flowpaths to the bypass flowpath in response to the filter media collecting increasing amounts of debris. More specifically, initially substantially all of the flow may be through the filtration flowpaths, and thereafter the filtration flowpaths may become substantially obstructed so that substantially all of the flow is through the bypass flowpath.