The invention belongs to the technical field of nuclear reactor materials design, and discloses a method for improving the withstanding capability of the cladding material in the fast neutron irradiation environment, comprising the following steps: selecting the cladding material with the annular structure and placing it on the outer side of the metallic fuel slug, with leaving a 0.2-0.8 mm gap between the metallic fuel slug and the cladding material; processing the operation in a reactor subsequently, with an annealing process of the fast neutron reactor fuel during the operation of the reactor; improves the withstanding capability of the cladding material in the fast neutron irradiation environment. The invention processes annealing treatment of the cladding material by balancing the internal and external stresses, multiple cycles of steady-state and transient operations, enhancing the withstanding capability of the steel in the high neutron irradiation environment, improving the lifetime of the cladding material.

The invention relates to the technical field of nuclear reactor materials, in particular to a processing method for improving the corrosion resistance of iron and steel materials in lead or lead-bismuth, comprising the following steps: selecting iron and steel materials containing Mn and Cr elements, using high-energy fast neutrons generated by fission as the radiation source, and performing irradiation on the iron and steel material so that Mn and Cr elements diffuse to the surface of the iron and steel material to form a dense oxide film, so as to complete the improvement of the corrosion resistance of the iron and steel material. The invention enhances the formation of the dense-structured oxide layer by irradiation. The oxide layer has good protection and self-healing properties in irradiation environment, and a new solution is proposed for enhancing the corrosion resistance of steel in lead and lead-bismuth coolant fast reactors.

A mobile heat pipe cooled fast nuclear reactor may be configured for transportation to remote locations and may be able to provide 0.5 to 2 megawatts of power. The mobile heat pipe cooled fast reactor may contain a plurality of heat pipes that are proximate to a plurality of fuel pins inside the reactor. The plurality of heat pipes may extend out of the reactor. The reactor may be configured to be placed in a standard shipping container, and may further be configured to be contained within a cask and attached to a skid for easier transportation.

A mobile heat pipe cooled fast nuclear reactor may be configured for transportation to remote locations and may be able to provide 0.5 to 2 megawatts of power. The mobile heat pipe cooled fast reactor may contain a plurality of heat pipes that are proximate to a plurality of fuel pins inside the reactor. The plurality of heat pipes may extend out of the reactor. The reactor may be configured to be placed in a standard shipping container, and may further be configured to be contained within a cask and attached to a skid for easier transportation.

A travelling wave reactor for a space exploration. A reactor core of the travelling wave reactor is dispersed into several modules in a travelling wave direction; a new reactor is sequentially provided with a starting source module and a plurality of new fuel modules at zero burnup; all the modules are coaxially assembled in the travelling wave direction by means of an assembling parts, and each module further includes a heat pipe; the heat pipe in each module positioned at a front part sequentially passes through all the modules positioned at a rear portion thereof and extends out of the module at a rear end; and after a period of time of burn-up, the reactor core of the travelling wave reactor is provided with the starting source module, a spent fuel module, a critical fuel module and the new fuel module sequentially in the travelling wave direction.

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.

A fuel assembly for use in a nuclear reactor comprising a fuel bundle, a plenum header connection positioned on the fuel bundle, a mast extending from the fuel bundle, and a common fission gas plenum extending from the mast is disclosed. The reactor includes a vessel and coolant situated within the vessel. The fuel bundle comprises a plurality of fuel elements including nuclear fuel material positioned therein. The plenum header connection comprises a plurality of passageways defined therein that are in fluid communication with the nuclear fuel material. The elongate mast comprises an internal passage connecting the common fission gas plenum to the plurality of passageways of the plenum header connection such that the common fission gas plenum is configured to receive an amount of fission gas generated by the nuclear fuel material during operation. The common fission gas plenum is positioned in an otherwise unused portion of the vessel.

The present invention relates to a travelling wave reactor for a space exploration. A reactor core of the travelling wave reactor is dispersed into several modules in a travelling wave direction; a new reactor is sequentially provided with a starting source module and a plurality of new fuel modules at zero burnup; all the modules are coaxially assembled in the travelling wave direction by means of an assembling parts, and each module further includes a heat pipe; during assembly, the heat pipe in each module positioned at a front part sequentially passes through all the modules positioned at a rear portion thereof and extends out of the module at a rear end; and after a period of time of burn-up, the reactor core of the travelling wave reactor is provided with the starting source module, a spent fuel module, a critical fuel module and the new fuel module sequentially in the travelling wave direction.

Methods and systems for stabilizing spent fuel assemblies from sodium-cooled nuclear reactors using Zamak are described herein. It has been determined that there is a synergism between Zamak and sodium that allows Zamak to form thermally-conductive interface with the sodium-wetted surfaces of the fuel assemblies. In the method, one or more spent fuel assemblies are removed from the sodium coolant pool and placed in a protective sheath. The remaining volume of the sheath is then filled with liquid Zamak. To a certain extent Zamak will dissolve and alloy with sodium remaining on the fuel assemblies. Excess sodium that remains undissolved is displaced from the sheath by the Zamak fill. The Zamak is then cooled until solid and the sheath sealed. The resulting Zamak-stabilized spent fuel assembly is calculated to have sufficient internal thermal conductivity to allow it to be stored and transported without the need for liquid cooling.

A fuel element has a ratio of area of fissionable nuclear fuel in a cross-section of the tubular fuel element perpendicular to the longitudinal axis to total area of the interior volume in the cross-section of the tubular fuel element that varies with position along the longitudinal axis. The ratio can vary with position along the longitudinal axis between a minimum of 0.30 and a maximum of 1.0. Increasing the ratio above and below the peak burn-up location associated with conventional systems reduces the peak burn-up and flattens and shifts the burn-up distribution, which is preferably Gaussian. The longitudinal variation can be implemented in fuel assemblies using fuel bodies, such as pellets, rods or annuli, or fuel in the form of metal sponge and meaningfully increases efficiency of fuel utilization.