A method of refueling a nuclear reactor that includes the steps of removing the reactor vessel head and upper internals to a storage location and installing a cylindrical tank having open upper and lower ends, on the reactor vessel flange. The cylindrical tank is sealed to the reactor vessel and a penetration on the side of the cylindrical tank is sealed to a refueling canal that is connected to a spent fuel pool. The level of reactor coolant within the reactor vessel is then raised to at least partially fill the cylindrical tank to a level equal to that of the spent fuel pool. The refueling canal is then opened and a refueling machine supported on the reactor vessel is employed to transfer fuel assemblies between the core and the spent fuel pool.

A system and method for removing spent fuel assemblies from a fuel building and transporting them to on-site facilities. A cask transporter is moved into the fuel building with an empty spent fuel storage cask, spent fuel assemblies are loaded into spent fuel storage cask, the cask is sealed, and the cask transporter moves the loaded spent fuel storage cask to a handling area for final disposal. Components of the system include a penetration cover, a lifting mechanism, a control system, a valve system, and the cask transporter.

A system and method for removing spent fuel assemblies from a fuel building and transporting them to on-site facilities. A cask transporter is moved into the fuel building with an empty spent fuel storage cask, spent fuel assemblies are loaded into spent fuel storage cask, the cask is sealed, and the cask transporter moves the loaded spent fuel storage cask to a handling area for final disposal. Components of the system include a penetration cover, a lifting mechanism, a control system, a valve system, and the cask transporter.

Exemplary embodiments provide automated nuclear fission reactors and methods for their operation. Exemplary embodiments and aspects include, without limitation, re-use of nuclear fission fuel, alternate fuels and fuel geometries, modular fuel cores, fast fluid cooling, variable burn-up, programmable nuclear thermostats, fast flux irradiation, temperature-driven surface area/volume ratio neutron absorption, low coolant temperature cores, refueling, and the like.

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.

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.

Disclosed embodiments include nuclear fission reactor cores, nuclear fission reactors, methods of operating a nuclear fission reactor, and methods of managing excess reactivity in a nuclear fission reactor.

The present invention relates to passive cooling systems and methods for cooling a spent fuel pool in a nuclear power plant in the absence of onsite and offsite power, e.g., in a station blackout event. The systems include a gap formed along the periphery of the spent fuel pool, a heat sink, one or more thermal conductive members, a water supply system for delivering water to at least partially fill the gap and conduct heat generated from the spent fuel pool through the gap to at least one thermal conductive member for transporting heat to the heat sink, and a thermal switch mechanism for activating and deactivating the water supply system. In particular, the passive spent fuel pool cooling systems and methods of the invention are useful when the active spent fuel pool cooling system is unavailable or inoperable.

An insulated solution injector may include an outer tube and an inner tube arranged within the outer tube. The outer tube and the inner tube may define an annular space therebetween, and the inner tube may define a solution space within. The annular space may be configured so as to insulate the solution within the solution space. As a result, the solution may be kept to a temperature below its decomposition temperature prior to injection. Accordingly, the decomposition of the solution and the resulting deposition of its constituents within the solution space may be reduced or prevented, thereby decreasing or precluding the occurrence of a blockage.

An insulated solution injector may include an outer tube and an inner tube arranged within the outer tube. The outer tube and the inner tube may define an annular space therebetween, and the inner tube may define a solution space within. The annular space may be configured so as to insulate the solution within the solution space. As a result, the solution may be kept to a temperature below its decomposition temperature prior to injection. Accordingly, the decomposition of the solution and the resulting deposition of its constituents within the solution space may be reduced or prevented, thereby decreasing or precluding the occurrence of a blockage.