A method of loading fuel in multiple reactor cores associated with a plurality of fuel cycles. The method includes, in a first fuel cycle, loading a first reactor core with a first fuel assembly selected from a first batch of fuel, loading the first reactor core with a first partially spent fuel assembly from a second batch of fuel, loading a second reactor core with a second fuel assembly from the first batch of fuel, and loading the second reactor core with a second partially spent fuel assembly from the second batch of fuel. In a second fuel cycle, which is performed after a completion of the first fuel cycle, the method includes loading the second reactor core with a fresh fuel assembly, and loading the second reactor core with the first fuel assembly from the first batch of fuel.

Process for manufacturing a nuclear component comprising i) a support containing a substrate based on a metal (1), the substrate (1) being coated or not coated with an interposed layer (3) positioned between the substrate (1) and at least one protective layer (2) and ii) the protective layer (2) composed of a protective material comprising amorphous chromium carbide; the process comprising a step a) of vaporizing a mother solution followed by a step b) of depositing the protective layer (2) onto the support via a process of chemical vapor deposition of an organometallic compound by direct liquid injection (DLI-MOCVD).

Process for manufacturing a nuclear component comprising i) a support containing a substrate based on a metal (1), the substrate (1) being coated or not coated with an interposed layer (3) positioned between the substrate (1) and at least one protective layer (2) and ii) the protective layer (2) composed of a protective material comprising amorphous chromium carbide; the process comprising a step a) of vaporizing a mother solution followed by a step b) of depositing the protective layer (2) onto the support via a process of chemical vapor deposition of an organometallic compound by direct liquid injection (DLI-MOCVD).

There is provided a core of a boiling water reactor that can be operated without loading a new fuel assembly at an operation cycle before decommissioning. The core of the boiling water reactor includes multiple fuel assemblies loaded in a square lattice shape. The multiple fuel assemblies are arranged in the core based on the number of residence cycles of fuel assemblies laterally adjacent and longitudinally adjacent to a fuel assembly having the shortest loading period in core cross section. The arrangement of fuel assemblies is also based on the number of residence cycles of fuel assemblies diagonally adjacent to the fuel assembly having the shortest loading period.

There is provided a core of a boiling water reactor that can be operated without loading a new fuel assembly at an operation cycle before decommissioning. The core of the boiling water reactor includes multiple fuel assemblies loaded in a square lattice shape. The multiple fuel assemblies are arranged in the core based on the number of residence cycles of fuel assemblies laterally adjacent and longitudinally adjacent to a fuel assembly having the shortest loading period in core cross section. The arrangement of fuel assemblies is also based on the number of residence cycles of fuel assemblies diagonally adjacent to the fuel assembly having the shortest loading period.

When all fuel assemblies loaded in a region excluding an outermost periphery of the reactor core in an Nth operation cycle belong to the first fuel assembly, and all fuel assemblies loaded in the region excluding the outermost periphery of the reactor core in a (N+m) th (m>1) operation cycle belong to the second fuel assembly, the number of new loaded second fuel assemblies in the (N+m) th operation cycle is greater than the number of new loaded second fuel assemblies in a (N+m1) th operation cycle which is one operation cycle before the (N+m) th operation cycle, and a cycle burnup in the (N+m) th operation cycle is greater than a cycle burnup in the (N+m1) th operation cycle.

Some embodiments include a molten salt system comprising a reactor with a salt mixture. In some embodiments, the salt mixture includes uranium and a eutectic salt. The eutectic salt may include one or more of sodium fluoride, potassium fluoride, aluminum fluoride, zirconium fluoride, lithium fluoride, beryllium fluoride, rubidium fluoride, magnesium fluoride, calcium fluoride, sodium chloride, potassium chloride, aluminum chloride, zirconium chloride, lithium chloride, beryllium chloride, rubidium chloride, magnesium chloride, and calcium chloride. The eutectic salt may have a melting point less than about 800 C.

Some embodiments include a method comprising: flowing a molten salt out of a molten salt reactor at a first temperature, heating the molten salt reactor to a second temperature above the melding point of the second salt mixture causing the second salt mixture to melt; flowing the second salt mixture out of the molten salt reactor; flowing a third salt mixture into the molten salt reactor; and cooling the molten salt reactor from the second temperature to a third temperature causing the third salt mixture to solidify on the interior surface of the housing. In some embodiments, the molten salt may include a first salt mixture comprising at least uranium. In some embodiments, the first temperature is a temperature above the melting point of the first salt mixture.

Some embodiments include a method comprising: flowing a molten salt out of a molten salt reactor at a first temperature, heating the molten salt reactor to a second temperature above the melding point of the second salt mixture causing the second salt mixture to melt; flowing the second salt mixture out of the molten salt reactor; flowing a third salt mixture into the molten salt reactor; and cooling the molten salt reactor from the second temperature to a third temperature causing the third salt mixture to solidify on the interior surface of the housing. In some embodiments, the molten salt may include a first salt mixture comprising at least uranium. In some embodiments, the first temperature is a temperature above the melting point of the first salt mixture.

Process for manufacturing a nuclear component comprising i) a support containing a substrate based on a metal (1), the substrate (1) being coated or not coated with an interposed layer (3) positioned between the substrate (1) and at least one protective layer (2) and ii) the protective layer (2) composed of a protective material comprising amorphous chromium carbide; the process comprising a step a) of vaporizing a mother solution followed by a step b) of depositing the protective layer (2) onto the support via a process of chemical vapor deposition of an organometallic compound by direct liquid injection (DLI-MOCVD).

Nuclear component comprising i) a support containing a substrate based on a metal, the substrate (1) being coated or not coated with an interposed layer (3) positioned between the substrate (1) and at least one protective layer (2) and ii) the protective layer (2) composed of a protective material comprising amorphous chromium carbide. The composite nuclear component manufactured by the process of the invention has improved resistance to oxidation, hydriding and/or migration of undesired material.

The invention also relates to the use of the nuclear component for combating oxidation and/or hydriding.