Device for producing energy by nuclear fission, and methods of using same. The device comprises a core container of a core container material, which core container encloses an inner tubing of an inner tubing material. The inner tubing and/or the core container has(have) an inlet and an outlet. The device also comprises a molten fuel salt with a fissionable material and a molten moderator salt comprising metal hydroxide(s), metal deuteroxide(s) or a combination thereof and a redox-element having a reduction potential, which is larger than that of the inner tubing material or of the inner tubing material and the core container material. The molten moderator salt is located in the core container, and the molten fuel salt is located in the inner tubing. Alternatively, the molten fuel salt is located in the core container, and the molten moderator salt is located in the inner tubing.

Device for producing energy by nuclear fission, and methods of using same. The device comprises a core container of a core container material, which core container encloses an inner tubing of an inner tubing material. The inner tubing and/or the core container has(have) an inlet and an outlet. The device also comprises a molten fuel salt with a fissionable material and a molten moderator salt comprising metal hydroxide(s), metal deuteroxide(s) or a combination thereof and a redox-element having a reduction potential, which is larger than that of the inner tubing material or of the inner tubing material and the core container material. The molten moderator salt is located in the core container, and the molten fuel salt is located in the inner tubing. Alternatively, the molten fuel salt is located in the core container, and the molten moderator salt is located in the inner tubing.

The present invention relates generally to the field of compensation methods for nuclear reactors and, in particular to a method for fail-safe reactivity compensation in solution-type nuclear reactors. In one embodiment, the fail-safe reactivity compensation method of the present invention augments other control methods for a nuclear reactor. In still another embodiment, the fail-safe reactivity compensation method of the present invention permits one to control a nuclear reaction in a nuclear reactor through a method that does not rely on moving components into or out of a reactor core, nor does the method of the present invention rely on the constant repositioning of control rods within a nuclear reactor in order to maintain a critical state.

The present invention relates generally to the field of compensation methods for nuclear reactors and, in particular to a method for fail-safe reactivity compensation in solution-type nuclear reactors. In one embodiment, the fail-safe reactivity compensation method of the present invention augments other control methods for a nuclear reactor. In still another embodiment, the fail-safe reactivity compensation method of the present invention permits one to control a nuclear reaction in a nuclear reactor through a method that does not rely on moving components into or out of a reactor core, nor does the method of the present invention rely on the constant repositioning of control rods within a nuclear reactor in order to maintain a critical state.

Nuclear reactor systems and associated devices and methods are described herein. A representative nuclear reactor system includes a reactor vessel having a barrier separating a core region from a shield region. A plurality of fuel rods containing a liquid nuclear fuel are positioned in the core region. A liquid moderator material is also positioned in the core region at least partially around the fuel rods. A plurality of heat exchangers can be positioned in the shield region, and a plurality of heat pipes can extend through the barrier. The moderator material is positioned to transfer heat received from the liquid nuclear fuel to the heat pipes, and the heat pipes are positioned to transfer heat received from the moderator material to the heat exchangers. The heat exchangers can transport the heat out of the system for use in one or more processes, such as generating electricity.

A closed-vessel molten salt reactor (cvMSR) is described herein. A cvMSR may comprise a suspended container, such as a metallic container, within a trench surrounded by a concrete enclosure and a concrete cover having a number of channels. The suspended container may be hollow and a solution of fissile materials and salt materials may be provided within the suspended container. The solution may be capable of undergoing a chain reaction nuclear fission process once a threshold temperature is reached. Heat generated by the solution may heat a fluid surrounding the suspended container. The heated fluid may be transported, through the number of channels of the concrete cover, to an external location where the heated fluid may be used in distributing heat and/or electricity generation.

Heat exchanger assemblies are provided that can include: a heat exchanger housing; at least one primary conduit operably coupled to the heat exchanger housing and configured to convey a primary heat exchange fluid; at least one secondary conduit operably coupled to the heat exchanger housing and configured to convey a secondary heat exchange fluid; at least one thermal interface between the primary and secondary fluids; and at least one sensor operably engaged with the thermal interface. Heat exchanger assemblies including molten salt, liquid metal, or water/steam as part of the heat exchange fluids of the heat exchanger assembly are provided. The heat exchanger assemblies can include: at least one thermal interface between primary and secondary heat exchange fluids of the heat exchanger assembly; and a sensor operably engaged with the at least one interface. The sensor must be installed in conjunction with the heat exchanger fabrication process as an embedded sensor. Methods for determining the structural integrity of a thermal interface within a heat exchanger assembly using the sensor are provided. The methods can include, while at least one or both of the primary or secondary conduits contain heat exchange fluid, reading structural integrity information of the thermal interface between the heat exchange fluids using one or more sensors engaged with the thermal interface.

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 include an auxiliary cooling system which shared part of the primary coolant loop but allows for passive cooling of decay heat from the reactor. Furthermore, different pump configurations for circulating molten fuel through the reactor core and one or more in vessel heat exchangers are described.

A molten salt reactor includes a nuclear reactor core for sustaining a nuclear fission reaction fueled by a molten fuel salt. A molten fuel salt control system removes a volume of the molten fuel salt from the nuclear reactor core to maintain a reactivity parameter within a range of nominal reactivity. The molten fuel salt control system includes a molten fuel salt exchange system that fluidically couples to the nuclear reactor core and exchanges a volume of the molten fuel salt with a volume of a feed material containing a mixture of a selected fertile material and a carrier salt. The molten fuel salt control system can include a volumetric displacement control system having one or more volumetric displacement bodies insertable into the nuclear reactor core. Each volumetric displacement body can remove a volume of molten fuel salt from the nuclear reactor core, such as via a spill-over system.