Methods of controlling the reactivity of a molten salt fission reactor. The molten salt fission reactor comprises a core and a coolant tank (101), the core comprising fuel tubes (103) containing a molten salt fissile fuel, and the coolant tank containing a molten salt coolant (102), wherein the fuel tubes are immersed in the coolant tank. The methods comprise dissolving a neutron absorbing compound in the molten salt coolant, the neutron absorbing compound comprising a halogen and a neutron absorbing element. The first method further comprises reducing the neutron absorbing compound to a salt of the halogen and an insoluble substance comprising the neutron absorbing element, the halogen being fluorine or chlorine, wherein the insoluble substance is not volatile at a temperature of the coolant during operation of the reactor. In the second method the one or more neutron absorbing compounds are chosen such that reduction of the neutron absorbing capacity of the one or more neutron absorbing compounds due to absorption of neutrons compensates for a fall in reactivity of the core in order to control fission rates in the core. Apparatus for implementing the methods are also provided.

A molten salt nuclear reactor a neutron moderator core that has an inner region that defines channels of a first diameter separated by a first pitch and, an outer region that defines channels of a second diameter separated by a second pitch. The first diameter is larger than the second diameter and the first pitch is larger than the second pitch. This configuration allows for an increased capture of neutrons by fertile elements in the outer region. That is, less neutrons are lost to the outside of the core. The configuration is such that the neutron multiplication factor is larger than one in the inner portion and lower than one in the outer portion.

A molten salt nuclear reactor a neutron moderator core that has an inner region that defines channels of a first diameter separated by a first pitch and, an outer region that defines channels of a second diameter separated by a second pitch. The first diameter is larger than the second diameter and the first pitch is larger than the second pitch. This configuration allows for an increased capture of neutrons by fertile elements in the outer region. That is, less neutrons are lost to the outside of the core. The configuration is such that the neutron multiplication factor is larger than one in the inner portion and lower than one in the outer portion.

An experimental system a method for studying jet impact characteristics at a core outlet of a fast reactor are provided. The system includes a jet impact main loop including a water storage tank, plunger pumps, a filter, preheaters, a jet impact chamber, a heat regenerator, a condenser, valves, flow meters and pipelines connecting these facilities; a cooling loop including cooling tower, a cooling pump, a regulating valve and a flow meter; and a makeup water loop including a deionized water machine, a makeup water tank and a plunger pump. Water in the water storage tank flows to the heat regenerator via the plunger pump, is preliminarily heated by the heat regenerator and then is divided into three branches to flow to the jet impact container.

An experimental system a method for studying jet impact characteristics at a core outlet of a fast reactor are provided. The system includes a jet impact main loop including a water storage tank, plunger pumps, a filter, preheaters, a jet impact chamber, a heat regenerator, a condenser, valves, flow meters and pipelines connecting these facilities; a cooling loop including cooling tower, a cooling pump, a regulating valve and a flow meter; and a makeup water loop including a deionized water machine, a makeup water tank and a plunger pump. Water in the water storage tank flows to the heat regenerator via the plunger pump, is preliminarily heated by the heat regenerator and then is divided into three branches to flow to the jet impact container.

Configurations of molten fuel salt reactors are described that allow for active cooling of the containment vessel of the reactor by the primary coolant. Furthermore, naturally circulating reactor configurations are described in which the reactor cores are substantially frustum-shaped so that the thermal center of the reactor core is below the outlet of the primary heat exchangers. Heat exchanger configurations are described in which welded components are distanced from the reactor core to reduce the damage caused by neutron flux from the reactor. Radial loop reactor configurations are also described.

Configurations of molten fuel salt reactors are described that allow for active cooling of the containment vessel of the reactor by the primary coolant. Furthermore, naturally circulating reactor configurations are described in which the reactor cores are substantially frustum-shaped so that the thermal center of the reactor core is below the outlet of the primary heat exchangers. Heat exchanger configurations are described in which welded components are distanced from the reactor core to reduce the damage caused by neutron flux from the reactor. Radial loop reactor configurations are also described.

A nuclear reactor is designed to couple the load path of the control elements with the reactor core, thus reducing the opportunity for differential movement between the control elements and the reactor core. A cartridge core barrel can be fabricated in a manufacturing facility to include the reactor core, control element supports, and control element drive system. The cartridge core barrel can be mounted to a reactor vessel head, and any movement, such as through seismic forces, transmits an equal direction and magnitude to the control elements and the reactor core, thus inhibiting the opportunity for differential movement.

The present invention relates to a molten salt-metal reactor for implementing a micro-reactor, and more specifically, to a molten salt-metal reactor including a liquid metal nuclear fuel and a molten salt coolant, wherein the molten salt coolant is disposed in an upper portion of the liquid metal nuclear fuel such that the heat generated from the nuclear fuel is transferred to the molten salt coolant and cooled.

A nuclear reactor is provided that comprises a vessel that houses a core, comprising a bundle of fuel elements, and immersed in a primary cooling fluid of the core; the fuel elements extend along respective longitudinal and parallel axes and are mechanically supported by respective heads joined to each other and joined to an anchoring structure by support devices acting between adjacent fuel elements, or acting between fuel elements situated on the periphery of the core and the anchoring structure, and which constitute an integral part of the heads of the fuel elements.