A vaporizer includes an outer tube configured to receive a flow of heated gas and an inner tube disposed at least partially within the outer tube. The inner tube is spaced apart from the outer tube such that the flow of heated gas is channeled through an annular space therebetween. The vaporizer also includes a crucible disposed at least partially within the inner tube. The crucible is extendable and retractable relative to the inner tube and within the outer tube. The crucible is configured to hold a molten metal such that a surface area of the molten metal exposed to the flow of heated gas is adjustable based on the position of the crucible relative to the inner tube. A heater is configured to vaporize the molten material and the vapor mixes with the flow of heated gas.

A combined power generation system and method of a small fluoride-salt-cooled high-temperature reactor and solar tower is provided, which belongs to the field of new energy and renewable energy application and includes: a nuclear reactor power generation system, a solar tower power generation system and a heat compensation system. Both the nuclear reactor power generation system and the solar tower power generation system adopt supercritical carbon dioxide Brayton cycle system to generate electricity efficiently; molten salt pool in the nuclear reactor power generation system stores high-temperature heat from the modular reactor, and multi-stage temperature heat is utilized for generating power and compensating heat required by the solar tower power generation system.

A combined power generation system and method of a small fluoride-salt-cooled high-temperature reactor and solar tower is provided, which belongs to the field of new energy and renewable energy application and includes: a nuclear reactor power generation system, a solar tower power generation system and a heat compensation system. Both the nuclear reactor power generation system and the solar tower power generation system adopt supercritical carbon dioxide Brayton cycle system to generate electricity efficiently; molten salt pool in the nuclear reactor power generation system stores high-temperature heat from the modular reactor, and multi-stage temperature heat is utilized for generating power and compensating heat required by the solar tower power generation system.

A method comprising measuring a number of gamma-ray counts in a gamma-ray sensitive detector (60) that is placed outside a biological shield (10) near a primary cooling circuit (30) of a nuclear power plant, and determining the thermal power of the nuclear power plant based on the number of gamma-ray counts measured in the gamma-ray sensitive detector (60).

A method comprising measuring a number of gamma-ray counts in a gamma-ray sensitive detector (60) that is placed outside a biological shield (10) near a primary cooling circuit (30) of a nuclear power plant, and determining the thermal power of the nuclear power plant based on the number of gamma-ray counts measured in the gamma-ray sensitive detector (60).

The invention relates to safe operation support systems of nuclear power plants (NPPs) at severe accidents, including methods and systems for cooling and cooling control of the reactors molten core. The invention increases safety of NPP and cooling efficiency of the molten core of a reactor. The invention increases the efficiency of cooling the molten core of a reactor by safely removing the heat load from the molten metal mirror, ensuring the elimination of vapor explosions. The invention changes the principle of cooling the reactor molten core, in that after the molten core destroys the reactor vessel, the conditions for subsequent cooling of the molten metal are determined by the characteristics of the trap casing, but not of the reactor.

A method for depositing zinc on the surfaces of a coolant loop of a nuclear power plant includes: providing within a portion of the coolant loop a treatment solution comprising zinc and optionally one or more noble metals and/or reducing agent(s); allowing the treatment solution to remain in the portion for a treatment period; and removing the treatment solution from the portion. According to various embodiments, an average temperature of the treatment solution over the course of the treatment period is less than 150° C. or 100° C. According to various embodiments, an instantaneous temperature of the treatment solution remains below 150° C. or 100° C. throughout the treatment period. The zinc deposition treatment may be applied (1) before the plant is first put into power-generating operation or (2) during an outage following power-generating operation and optionally following a chemical decontamination to remove any oxides formed on surfaces of a coolant loop during prior power operation period(s).

A vaporizer includes an outer tube configured to receive a flow of heated gas and an inner tube disposed at least partially within the outer tube. The inner tube is spaced apart from the outer tube such that the flow of heated gas is channeled through an annular space therebetween. The vaporizer also includes a crucible disposed at least partially within the inner tube. The crucible is extendable and retractable relative to the inner tube and within the outer tube. The crucible is configured to hold a molten metal such that a surface area of the molten metal exposed to the flow of heated gas is adjustable based on the position of the crucible relative to the inner tube. A heater is configured to vaporize the molten material and the vapor mixes with the flow of heated gas.

A computer-implemented simulation method of predicting local concentrations of constituents in coolant water anywhere along fuel rods within any fuel assembly mechanical design of a Boiling Water Reactor (BWR) potentially resulting in crud deposits on said fuel rods. The method is based on a sub-channel approach of predicting local mass fluxes of vapor and liquid in coolant water anywhere along fuel rods within any fuel assembly mechanical design of a Boiling Water Reactor (BWR) for given steady-state or transient boundary conditions. The sub-channel approach is based on the solution of mass, momentum and energy conservation equations for the vapor phase and the liquid phase, the liquid phase is represented by more than one field variable, and is specifically represented by three fields, with the vapor phase as a fourth field, consisting of droplets, a liquid base film, and disturbance waves. The method comprises:

simulating steady-state or transient boundary conditions, such as inlet coolant water flow into said sub-channels, the coolant water flow may have a predetermined flow velocity variation,

analyzing predefined parameters of said disturbance waves and base film, including wave velocity, wave frequency and base film thickness, and

analyzing liquid base film thickness between consecutive passing disturbance waves, to calculate local instantaneous impurity concentrations based on said simulated boundary conditions, the calculation is made for each fuel rod of the fuel assembly, wherein, for each fuel rod, the method further comprises comparing said calculated local instantaneous impurity concentration to a crud compound precipitation limit, and during the time said concentration is higher than said precipitation limit, crud is considered to have occurred. In a related simulation method also base film dryout, clad temperature increase, and drop entrainment from waves, may be determined.

A computer-implemented simulation method of predicting local concentrations of constituents in coolant water anywhere along fuel rods within any fuel assembly mechanical design of a Boiling Water Reactor (BWR) potentially resulting in crud deposits on said fuel rods. The method is based on a sub-channel approach of predicting local mass fluxes of vapor and liquid in coolant water anywhere along fuel rods within any fuel assembly mechanical design of a Boiling Water Reactor (BWR) for given steady-state or transient boundary conditions. The sub-channel approach is based on the solution of mass, momentum and energy conservation equations for the vapor phase and the liquid phase, the liquid phase is represented by more than one field variable, and is specifically represented by three fields, with the vapor phase as a fourth field, consisting of droplets, a liquid base film, and disturbance waves. The method comprises:

simulating steady-state or transient boundary conditions, such as inlet coolant water flow into said sub-channels, the coolant water flow may have a predetermined flow velocity variation,

analyzing predefined parameters of said disturbance waves and base film, including wave velocity, wave frequency and base film thickness, and

analyzing liquid base film thickness between consecutive passing disturbance waves, to calculate local instantaneous impurity concentrations based on said simulated boundary conditions, the calculation is made for each fuel rod of the fuel assembly, wherein, for each fuel rod, the method further comprises comparing said calculated local instantaneous impurity concentration to a crud compound precipitation limit, and during the time said concentration is higher than said precipitation limit, crud is considered to have occurred. In a related simulation method also base film dryout, clad temperature increase, and drop entrainment from waves, may be determined.