A method of forming one or more structures by additive manufacturing comprises introducing a first layer of a powder mixture comprising graphite and a fuel on a surface of a substrate. The first layer is at least partially compacted and then exposed to laser radiation to form a first layer of material comprising the fuel dispersed within a graphite matrix material. At least a second layer of the powder mixture is provided over the first layer of material and exposed to laser radiation to form inter-granular bonds between the second layer and the first layer. Related structures and methods of forming one or more structures are also disclosed.

A nuclear fuel assembly is constructed with fuel assembly components that are wire wrapped and positioned in hexagonal rings within a fuel assembly duct. The fuel assembly components positioned in an outermost ring of the fuel assembly are wire wrapped with a pitch that is shorter than fuel assembly components positioned at an interior ring of the fuel assembly. The shorter pitch at the outer ring of the fuel assembly increases pressure drop of a coolant fluid at the edge and corner subchannels and thereby reduces the temperature gradient across the fuel assembly, which provides a higher output temperature of the nuclear reactor without substantially increasing peak temperature of the fuel cladding.

A nuclear fuel assembly is constructed with fuel assembly components that are wire wrapped and positioned in hexagonal rings within a fuel assembly duct. The fuel assembly components positioned in an outermost ring of the fuel assembly are wire wrapped with a pitch that is shorter than fuel assembly components positioned at an interior ring of the fuel assembly. The shorter pitch at the outer ring of the fuel assembly increases pressure drop of a coolant fluid at the edge and corner subchannels and thereby reduces the temperature gradient across the fuel assembly, which provides a higher output temperature of the nuclear reactor without substantially increasing peak temperature of the fuel cladding.

A nuclear reactor is constructed in sub-modules and super modules which are manufactured, packaged, and shipped to a construction site. At least some of the modules are packaged in suitable shielding containers or portions of containers, which may be steel. The modules are assembled on-site, and some of the modules remain within their respective shipping containers after assembly. One or more of the shipping containers may be used as concrete forms to support the pouring of concrete in between selected modules. The concrete may be used for structural support, shielding, or both.

A nuclear reactor is constructed in sub-modules and super modules which are manufactured, packaged, and shipped to a construction site. At least some of the modules are packaged in suitable shielding containers or portions of containers, which may be steel. The modules are assembled on-site, and some of the modules remain within their respective shipping containers after assembly. One or more of the shipping containers may be used as concrete forms to support the pouring of concrete in between selected modules. The concrete may be used for structural support, shielding, or both.

A nuclear system. The nuclear system includes a fuel rod for use in a nuclear reactor. The fuel rod includes a cladding comprising an interior region, unspent fuel pellets housed in the interior region of the cladding, and a resonant electrical circuit supported within the interior region of the cladding. The resonant electrical circuit is configured to receive an excitation pulse through the cladding, and responsive to the received excitation pulse, generate a response pulse in the form of a magnetic field signal that is structured to travel wirelessly from the interior region and through the cladding. The nuclear system also includes a receiver positioned outside of the cladding and within the nuclear reactor. The receiver is configured to receive the response pulse and generate an output based on the received response pulse.

A nuclear system. The nuclear system includes a fuel rod for use in a nuclear reactor. The fuel rod includes a cladding comprising an interior region, unspent fuel pellets housed in the interior region of the cladding, and a resonant electrical circuit supported within the interior region of the cladding. The resonant electrical circuit is configured to receive an excitation pulse through the cladding, and responsive to the received excitation pulse, generate a response pulse in the form of a magnetic field signal that is structured to travel wirelessly from the interior region and through the cladding. The nuclear system also includes a receiver positioned outside of the cladding and within the nuclear reactor. The receiver is configured to receive the response pulse and generate an output based on the received response pulse.

An enclosure for non-organic electronic components is provided which includes an inner cavity for housing non-organic electronic components and a neutron shielding barrier surrounding the inner cavity and the electronic components housed within the cavity. The barrier is formed from a neutron reflecting material in solid or powdered form and a neutron absorbing material in solid or powdered form. An optional structural support is provided in certain aspects of the enclosure design.

A transportable nuclear power system is provided. The system includes a nuclear power generator. The nuclear power generator includes one or more fuel cartridges configured to form a critical core during a power generation operation, each of the one or more fuel cartridges containing a nuclear fuel. The nuclear power generator also includes a reactivity controller and one or more working fluid conduits, each work fluid conduit containing a working fluid circulating within each of the one or more fuel cartridges to cool the nuclear fuel and execute a thermodynamic cycle. The system also includes an ISO transport container including a support structure mounted inside the ISO transport container to support at least the one or more fuel cartridges of the nuclear power generator. The one or more fuel cartridges of the nuclear power generator are contained in the ISO transport container during the power generation operation.

Disclosed embodiments include fuel ducts, fuel assemblies, methods of making fuel ducts, methods of making a fuel assembly, and methods of using a fuel assembly. An inner hollow structure has a first geometry and an outer hollow structure has a second geometry different from the first geometry. The first hollow structure is configured to expand in at least one dimension under stress and cause the first hollow structure to contact the second hollow structure. The second hollow structure distributes at least a portion of the stress of the first hollow structure.