Abstract: A modular nuclear reactor comprises a plurality of sections arranged in a pattern and a side reflector material surrounding the plurality of sections. Each section includes a tank comprising a front plate, a back plate, side plates, a top plate, and a bottom plate. A plurality of grid plates are located within the tank. Each grid plate comprises a plurality of apertures and is vertically separated from an adjacent grid plate. The tank further includes a plurality of fuel elements extending through each grid plate. A plurality of heat pipes extend through each grid plate, the top plate, and an upper reflector. Methods of forming the modular nuclear reactor are also disclosed.

Abstract: A modular nuclear reactor comprises a central portion comprising a plurality of structures. Each structure comprises a fuel material surrounded by an outer cladding material, the fuel material defining an annular space at a center portion of the fuel material, a heat pipe disposed in the annular space, and an inner cladding between the fuel material and the heat pipe. The modular nuclear reactor further comprises a side reflector disposed around the central portion. Related modular nuclear reactors and related methods are disclosed.

Abstract: A nuclear fuel element includes a core formed from a high density solid solution fissile material that is substantially free of carbon and void space. A cladding substantially surrounds the core.