The method of launching natural circulation of the liquid metal coolant in the heat sink circuit of the fast neutron nuclear reactor without connection to the main heat source (first circuit heat sink) and without using pumping equipment, but only as a result of electric heating of the downing and lifting sections of the heat sink circuit to the specified temperatures and, as a consequence, the occurring difference in the densities of the coolant on the lifting and downing sections of the heat sink circuit.

A nuclear reactor comprising: a moderator including a metal hydride; and a nuclear fuel in which europium is added as an additive to a main nuclear fuel material. Thus, the nuclear reactor can be kept in the subcritical state even under the state where all the control devices are pulled out before startup.

A nuclear reactor comprising: a moderator including a metal hydride; and a nuclear fuel in which europium is added as an additive to a main nuclear fuel material. Thus, the nuclear reactor can be kept in the subcritical state even under the state where all the control devices are pulled out before startup.

The invention concerns a liquid metal-cooled fast-neutron nuclear reactor (1), comprising a system (2) for removing at least part of both the nominal power and the residual power of the reactor, which ensures, at the same time: removal of the residual power in a totally passive manner from the initial instant of the accident; removal of the heat through the primary vessel; implementation of a final cold source (container with PCM) other than the sodium/air or NaK/air heat exchangers used in the prior art.

The invention concerns a liquid metal-cooled fast-neutron nuclear reactor (1), comprising a system (2) for removing at least part of both the nominal power and the residual power of the reactor, which ensures, at the same time: removal of the residual power in a totally passive manner from the initial instant of the accident; removal of the heat through the primary vessel; implementation of a final cold source (container with PCM) other than the sodium/air or NaK/air heat exchangers used in the prior art.

A passive nuclear reactor control device. The passive nuclear reactor control device comprises a sealed chamber, which comprises a reservoir and a tube in fluid communication with the reservoir. A molten salt is within the sealed chamber, the molten salt being a eutectic mixture of a monovalent metal halide, and a fluoride or chloride of one or more lanthanides and/or a fluoride or chloride of hafnium. A gas is within the sealed chamber, and the gas does not react with the molten salt.

The method and system for control of oxygen concentration in the coolant of a reactor plant including a reactor, coolant in the reactor, gas system, mass-exchange apparatus, disperser and an oxygen sensor in the coolant have been disclosed. The method includes the following steps implemented by the system: estimation of the oxygen concentration; comparison of the oxygen concentration with the permissible value; if the oxygen concentration is reduced, comparison of the reduction value and\or rate with the corresponding threshold value; if the reduction value and\or rate of oxygen concentration is below the threshold value, activation of the mass-exchange apparatus; if the reduction value and/or rate of oxygen concentration is above the corresponding threshold value, supply of oxygen-containing gas from the gas system to the near-coolant space and/or activation of the disperser. Technical result: improvement of controllability of oxygen concentration in coolant, enhancement of safety and extension of reactor plant operating life.

The method and system for control of oxygen concentration in the coolant of a reactor plant including a reactor, coolant in the reactor, gas system, mass-exchange apparatus, disperser and an oxygen sensor in the coolant have been disclosed. The method includes the following steps implemented by the system: estimation of the oxygen concentration; comparison of the oxygen concentration with the permissible value; if the oxygen concentration is reduced, comparison of the reduction value and\or rate with the corresponding threshold value; if the reduction value and\or rate of oxygen concentration is below the threshold value, activation of the mass-exchange apparatus; if the reduction value and/or rate of oxygen concentration is above the corresponding threshold value, supply of oxygen-containing gas from the gas system to the near-coolant space and/or activation of the disperser. Technical result: improvement of controllability of oxygen concentration in coolant, enhancement of safety and extension of reactor plant operating life.

The present invention describes a nuclear reactor with a loop for liquid nuclear fuel, which, contrary to similar systems like the Molten-Salt Reactor of the Generation-IV canon, does not use the fuel loop for the heat transport at the same time. Instead, cooling is provided by an additional coolant loop, which is intensively coupled to the nuclear fuel duct for heat transport. That way, the advantages of liquid fuel can be utilized while optimizing the coolant loop performance, so the complexity of safety systems can be reduced significantly. This reactor design further includes an optimized neutron economy and is able to deactivate long-lived fission products generated by its own, so only short-lived radiotoxic waste has to be stored. With the neutron surplus it is also possible to deactivate long-lived radiotoxic waste from used fuel of today's light water reactors or to produce medical radioisotopes.

A nuclear reactor is configured with an intermediate coolant loop for transferring thermal energy from the reactor core for a useful purpose. The intermediate coolant loop includes a bypass flowpath with an air heat exchanger for dumping reactor heat during startup and/or shutdown. A fluidic diode along the bypass flowpath asymmetrically restricts flow across the bypass flowpath, inhibiting flow in a first flow direction during a full power operating condition and allowing a relatively uninhibited flow in a second direction during a startup and/or shut down low power operating condition.