A thermal control system for a reactor pressure vessel comprises a plate having a substantially circular shape that is attached to a wall of the reactor pressure vessel. The plate divides the reactor pressure vessel into an upper reactor pressure vessel region and a lower reactor pressure vessel region. Additionally, the plate is configured to provide a thermal barrier between a pressurized volume located within the upper reactor pressure vessel region and primary coolant located within the lower reactor pressure vessel region. One or more plenums provide a passageway for a plurality of heat transfer tubes to pass through the wall of the reactor pressure vessel. The plurality of heat transfer tubes are connected to the plate.

An exemplary embodiment of the present invention provides a reactor system comprising: a reaction vessel comprising a reactant, a heat transfer fluid and a first reaction product, wherein the heat transfer fluid has a greater density than the first reaction product such that at least a portion of the first reaction product floats on a surface of the heat transfer fluid; a first outlet positioned at a surface level of the first reaction product, the first outlet configured to output a first outlet flow comprising at least a portion of the first reaction product and at least a portion of the heat transfer fluid; wherein the heat transfer fluid is configured to provide thermal energy to the reactant in the reaction vessel to form the first reaction product.

A passive shutdown system for a liquid metal cooled reactor may include a tube and a neutron absorber within the tube. The tube may be configured to extend through a core of the liquid metal cooled reactor. The tube has an upper end and a lower end. The tube defines a flow path for a liquid metal coolant. The neutron absorber is a mobile structure configured to partially obstruct a flow of the liquid metal coolant within the flow path. A method of operating a liquid metal cooled reactor may involve the use of the passive shutdown system.

A passive shutdown system for a liquid metal cooled reactor may include a tube and a neutron absorber within the tube. The tube may be configured to extend through a core of the liquid metal cooled reactor. The tube has an upper end and a lower end. The tube defines a flow path for a liquid metal coolant. The neutron absorber is a mobile structure configured to partially obstruct a flow of the liquid metal coolant within the flow path. A method of operating a liquid metal cooled reactor may involve the use of the passive shutdown system.

A rod transfer assembly has an outer rotating plug. A pick-up arm assembly extends from the outer rotating plug and includes a pivoting arm. An inner rotating plug is disposed off-center from and within the outer rotating plug and is rotatable independent of a rotation of the outer rotating plug. An access port rotating plug is disposed off-center from and within the inner rotating plug and is rotatable independent of rotation of the outer and inner rotating plugs. A pull arm extends from the access port rotating plug.

A rod transfer assembly has an outer rotating plug. A pick-up arm assembly extends from the outer rotating plug and includes a pivoting arm. An inner rotating plug is disposed off-center from and within the outer rotating plug and is rotatable independent of a rotation of the outer rotating plug. An access port rotating plug is disposed off-center from and within the inner rotating plug and is rotatable independent of rotation of the outer and inner rotating plugs. A pull arm extends from the access port rotating plug.

This invention relates to the monitoring and diagnosing of nuclear power plants for its thermal performance using the NCV Method. Its applicability comprises any nuclear reactor such as used for research producing a useful output. Its greatest applicability lies with conventional Pressurized Water Reactor and Boiling Water Reactor nuclear plants generating an electric power. Its teachings of treating fission as an inertial process, a phenomena which is self-contained following incident neutron capture, allows the determination of an absolute neutron flux. This process is best treated by Second Law principles producing a total fission exergy. This invention also applies to the design of fusion thermal systems regards the determination of its Second Law viability and absolute plasma flux.

This invention relates to the monitoring and diagnosing of nuclear power plants for its thermal performance using the NCV Method. Its applicability comprises any nuclear reactor such as used for research producing a useful output. Its greatest applicability lies with conventional Pressurized Water Reactor and Boiling Water Reactor nuclear plants generating an electric power. Its teachings of treating fission as an inertial process, a phenomena which is self-contained following incident neutron capture, allows the determination of an absolute neutron flux. This process is best treated by Second Law principles producing a total fission exergy. This invention also applies to the design of fusion thermal systems regards the determination of its Second Law viability and absolute plasma flux.

A method of stabilizing density wave oscillations in boiling water reactor cores is disclosed. The invention introduced a thin metallic fuel element made of fissile isotope baring metal encased and bonded with metallic cladding. The thin construction and the metallic material guarantee very short thermal time constant compared with the oscillation period. Although the feedback of the processes involved in density waves are negative, i.e. oppose any initial perturbation, sufficiently strong feedback may result in unstable behavior because of the time delay inherent in the propagation of the density wave and the heat conduction delay in the traditional fuel rods made of ceramic pellets encased in zircaloy tubes. The new fuel element of this invention introduces fast, not delayed, thermal energy to the coolant in response of any neutron flux perturbation, and thus introduces a stabilizing feedback. Boiling water reactor fuel bundles may benefit from this invention by including the new fuel element as part of its array of fuel rods, preferably filling in the space vacated by part-length fuel rods.

Illustrative methods are provided for annealing nuclear fission reactor materials, such as without limitation, a nuclear fission reactor core or fuel assembly or components thereof within the nuclear core. Annealing a metallic component of a nuclear fission reactor within the reactor core may include determining an annealing temperature for at least a portion of at least one metallic component of a nuclear fission fuel assembly of the reactor. The temperature of the core may be adjusted to affect the determined annealing temperature, which in some cases may be greater than the predetermined operating temperature range of the nuclear fission fuel assembly. The portion of the at least one metallic component of the nuclear fission fuel assembly is annealed within the core at the annealing temperature range.