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.

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 container is rotatable between different orientations. The container may be hollow and a solution of fissile materials and salt materials may be provided within the 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 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.

A nuclear fission reactor comprising a core, a pool of coolant liquid, and a heat exchanger. The core comprises an array of hollow tubes which contain molten salts of fissile isotopes. The tube array is at least partly immersed in the pool of coolant liquid. The tube array comprises a critical region, where the density of the fissile isotopes during operation of the reactor is sufficient to cause a self-sustaining fission reaction. Heat transfer from the molten salts of fissile isotopes to the tubes is achieved by any one or more of natural convection of the molten salts, mechanical stirring of the molten salts, and oscillating fuel salt flow within the tubes. The molten salts of fissile isotopes are contained entirely within the tubes during operation of the reactor.

A nuclear fission reactor comprising a core, a pool of coolant liquid, and a heat exchanger. The core comprises an array of hollow tubes which contain molten salts of fissile isotopes. The tube array is at least partly immersed in the pool of coolant liquid. The tube array comprises a critical region, where the density of the fissile isotopes during operation of the reactor is sufficient to cause a self-sustaining fission reaction. Heat transfer from the molten salts of fissile isotopes to the tubes is achieved by any one or more of natural convection of the molten salts, mechanical stirring of the molten salts, and oscillating fuel salt flow within the tubes. The molten salts of fissile isotopes are contained entirely within the tubes during operation of the reactor.

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.

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 loading system for a molten salt reactor system includes a slug loading assembly. The slug loading assembly includes an inert chamber having an entry port therein that is configured to receive a solid slug. The loading system further includes a chute having a pipe run extending from the entry port and elevationally below the slug loading assembly. The loading system further includes a terminal sieve fluidically coupled with the pipe run opposite the entry port and configured to receive the solid slug via the pipe run. The terminal sieve is positionable with a flow of a liquid molten salt for dissolution of the solid slug therein.

A loading system for a molten salt reactor system includes a slug loading assembly. The slug loading assembly includes an inert chamber having an entry port therein that is configured to receive a solid slug. The loading system further includes a chute having a pipe run extending from the entry port and elevationally below the slug loading assembly. The loading system further includes a terminal sieve fluidically coupled with the pipe run opposite the entry port and configured to receive the solid slug via the pipe run. The terminal sieve is positionable with a flow of a liquid molten salt for dissolution of the solid slug therein.

A nuclear reactor circuit contains nuclear fuel-containing molten salt in a channel which is substantially vertically arranged and provides an up-down passage. A modular reactor has removable, individual molten salt nuclear circuits. The channel of one circuit contains a non-critical amount of nuclear material, but the channels together create the critical zone of the reactor core. A method of operating a modular nuclear reactor circuit and a nuclear reactor include the use of the circuits.