A portable nuclear fuel cartridge comprising a unitary support structure and a plurality of nuclear fuel assemblies that collectively form a nuclear fuel core. The nuclear fuel core is integrated into the unitary support structure to collectively form a self-supporting assemblage than can be lifted as a single unit. In another aspect, the invention is a method of fueling and/or defueling a nuclear reactor utilizing a nuclear fuel cartridge that is loaded and/or unloaded from the nuclear reactor as a single unit. In another aspect, a nuclear reactor core is provided that comprises a nuclear fuel core comprising; a plurality of first nuclear fuel assemblies, each of the plurality of first nuclear fuel assemblies having a first transverse cross-sectional configuration; and a plurality of second nuclear fuel assemblies, each of the plurality of second nuclear fuel assemblies having a second transverse cross-sectional configuration that is different than the first transverse cross-sectional configuration.

A portable nuclear fuel cartridge comprising a unitary support structure and a plurality of nuclear fuel assemblies that collectively form a nuclear fuel core. The nuclear fuel core is integrated into the unitary support structure to collectively form a self-supporting assemblage than can be lifted as a single unit. In another aspect, the invention is a method of fueling and/or defueling a nuclear reactor utilizing a nuclear fuel cartridge that is loaded and/or unloaded from the nuclear reactor as a single unit. In another aspect, a nuclear reactor core is provided that comprises a nuclear fuel core comprising; a plurality of first nuclear fuel assemblies, each of the plurality of first nuclear fuel assemblies having a first transverse cross-sectional configuration; and a plurality of second nuclear fuel assemblies, each of the plurality of second nuclear fuel assemblies having a second transverse cross-sectional configuration that is different than the first transverse cross-sectional configuration.

Methods, systems, and devices for producing hot fluid from a reactor are disclosed. A mix of moderator particles, fuel particles, and reflector particles are configured to produce heat by nuclear reactions.

Methods, systems, and devices for producing hot fluid from a reactor are disclosed. A mix of moderator particles, fuel particles, and reflector particles are configured to produce heat by nuclear reactions.

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.

An active zone includes a homogeneous uranium-plutonium nitride fuel, the mass fraction of which is a minimum 0.305, and consists of central, intermediate and peripheral parts which form fuel assemblies comprising fuel elements with geometrically identical shells but differing heights. The radial distribution of the fuel across the volume of the active zone has a stepped shape. The radius of the central part is from 0.4 to 0.5 of the effective active zone radius, while the height of the fuel column in the fuel elements in the central part is from 0.5 to 0.8 of the height of the fuel column in the peripheral part. The heights of the fuel columns forming a stepped intermediate part for diameters ranging from 0.5 to 0.85 of the effective active zone diameter are within the range from 0.55 to 0.9 of the height of the fuel column in the peripheral part.

An active zone includes a homogeneous uranium-plutonium nitride fuel, the mass fraction of which is a minimum 0.305, and consists of central, intermediate and peripheral parts which form fuel assemblies comprising fuel elements with geometrically identical shells but differing heights. The radial distribution of the fuel across the volume of the active zone has a stepped shape. The radius of the central part is from 0.4 to 0.5 of the effective active zone radius, while the height of the fuel column in the fuel elements in the central part is from 0.5 to 0.8 of the height of the fuel column in the peripheral part. The heights of the fuel columns forming a stepped intermediate part for diameters ranging from 0.5 to 0.85 of the effective active zone diameter are within the range from 0.55 to 0.9 of the height of the fuel column in the peripheral part.

A block-type movable reflector/moderator (RM) for nuclear reactor control is disclosed. This reactor control system can be applied to all types of reactors regardless of design. This design for reactor control is used in addition to the necessary rod control system in accordance with the 10CFR50 design criteria. This allows for the requirements of the NRC to be met along with the ability for dual control on power control of any type reactor regardless of process output from the secondary plants.

A nuclear reactor core includes a plurality of fuel elements and moderator blocks to form a nuclear reactor core inner portion and a nuclear reactor core outer portion. The nuclear reactor core inner portion includes an inner moderator matrix formed of a plurality of inner holes that include a plurality of inner fuel openings with one or more fuel elements disposed therein. The plurality of inner holes further include a plurality of inner coolant passages to flow a coolant. The nuclear reactor core outer portion includes an outer moderator matrix formed of a plurality of outer holes that include a plurality of outer fuel openings with one or more fuel elements disposed therein. The plurality of outer holes further include a plurality of outer coolant passages to flow the coolant. The outer coolant passage diameter exceeds the inner coolant passage diameter.

A nuclear reactor core includes a plurality of fuel elements and moderator blocks to form a nuclear reactor core inner portion and a nuclear reactor core outer portion. The nuclear reactor core inner portion includes an inner moderator matrix formed of a plurality of inner holes that include a plurality of inner fuel openings with one or more fuel elements disposed therein. The plurality of inner holes further include a plurality of inner coolant passages to flow a coolant. The nuclear reactor core outer portion includes an outer moderator matrix formed of a plurality of outer holes that include a plurality of outer fuel openings with one or more fuel elements disposed therein. The plurality of outer holes further include a plurality of outer coolant passages to flow the coolant. The outer coolant passage diameter exceeds the inner coolant passage diameter.