Nuclear fuel rod

A nuclear fuel rod for a nuclear reactor of the boiling water type, comprising:

• a cladding tube, defining a closed inner space and which is manufactured from at least one of the materials in the group zirconium and a zirconium-based alloy;
• a plurality of nuclear fuel pellets, arranged in the inner space in the cladding tube so that the nuclear fuel pellets fill part of the inner space;
• a fill gas arranged in the closed inner space in order to fill the rest of the inner space;
• whereby the fill gas contains a proportion of inert gas and a proportion of carbon monoxide;
• and wherein
• the internal pressure (Pfill) of the fill gas in the nuclear fuel rod amounts to least about 2 bar (abs) at room temperature (TR) and the proportion of carbon monoxide is at least about 3 volume percent of the fill gas.

A nuclear fuel rod for a nuclear reactor of the pressurized water type, comprising:

• a cladding tube defining a closed inner space and which is manufactured from at least one of the materials in the group zirconium and a zirconium-based alloy;
• a plurality of nuclear fuel pellets, arranged in the inner space in the cladding tube so that the nuclear fuel pellets fill part of the inner space;
• a fill gas arranged in the closed inner space in order to fill the rest of the inner space;
• the fill gas containing a proportion of inert gas and a proportion of carbon monoxide;
• and wherein
• the internal pressure (Pfill) of the fill gas in the nuclear fuel rod amounts to at least about 10 bar (abs) at room temperature (TR) and that the proportion of carbon monoxide is at least about 2 volume percent of the fill gas.

A nuclear fuel assembly comprising a plurality of nuclear fuel rods, each fuel rod including:

• a cladding tube, defining a closed inner space and which is manufactured from at least one of the materials in the group zirconium and a zirconium-based alloy;
• a plurality of nuclear fuel pellets, arranged in the inner space in the cladding tube so that the nuclear fuel pellets fill part of the inner space;
• a fill gas arranged in the closed inner space in order to fill the rest of the inner space;
• whereby the fill gas contains a proportion of inert gas and a proportion of carbon monoxide;
• and wherein
• the internal pressure (Pfill) of the fill gas in the nuclear fuel rod amounts to least about 2 bar (abs) at room temperature (TR) and the proportion of carbon monoxide is at least about 3 volume percent of the fill gas.

A method for manufacturing a nuclear fuel rod for a nuclear reactor of the boiling water type, comprising the steps of:

• providing a cladding tube that defines an inner space and that is manufactured from at least one of the materials in the group zirconium and a zirconium-based alloy;
• introducing a plurality of nuclear fuel pellets, that are arranged in the inner space in the cladding tube so that the nuclear fuel pellets fill part of the inner space;
• filling up the inner space with a fill gas, that contains a proportion of inert gas and a proportion of carbon monoxide, in order to fill the rest of the inner space and concluding the inner space when an internal pressure, that amounts to at least about 2 bar (abs) at room temperature (TR), exists in the inner space;
• and
• whereby the proportion of carbon monoxide is greater than about 3 volume percent of the fill gas.

A method for manufacturing a nuclear fuel rod for a nuclear reactor of the pressurized water type, comprising the steps of:

• providing a cladding tube that defines an inner space and that is manufactured from at least one of the materials in the group zirconium and a zirconium-based alloy;
• introducing a pile of nuclear fuel pellets, that are arranged in the inner space in the cladding tube so that the nuclear fuel pellets fill part of the inner space;
• filling up the inner space with a fill gas, that contains a proportion of inert gas and a proportion of carbon monoxide, in order to fill the rest of the inner space and concluding the inner space when an internal pressure, that amounts to at least about 10 bar (abs) at room temperature (TR), exists in the inner space;
• and
• whereby the proportion of carbon monoxide is greater than about 2 volume percent of the fill gas.