Virtual analogue of Uranium-Water Subcritical Assembly (UWSA)

 

Virtual analog prototype

For many years, students of NRNU MEPhI have been studying at unique experimental facilities. One of these stands is an installation for determining the optimal pitch of the uranium-water lattice. The basis of the subcritical assembly is a water-filled cylindrical tank mounted on a graphite pedestal. Nuclear fuel (blocks of metallic uranium of natural isotopic composition in a sealed aluminum shell) is placed in channels fixed in the tank on a special device - a "beam shield". There are 162 channels filled with blocks. The central channel is empty. A detector is installed in it. The "beam shield" allows you to quickly mix the channels and precisely fix the hexagonal lattice pitch of 45, 50, 55 or 60 mm. The ratio of the volume of water to uranium in the unit cell varies from 0.4 to 2.5.

 

At the Uranium-Water Subcritical Assembly of MEPhI, students perform the laboratory work "Experimental determination of the dependence of the material parameter on the pitch of the uranium-water lattice", the purpose of which is to study the dependence of the material parameter on the lattice pitch.

Experimental facilities with nuclear materials are expensive and must undergo complex certification procedures to be usable. The virtual analogue allows you to carry out laboratory work even in the absence of a real assembly, which makes it possible to significantly expand laboratory work at much lower costs, taking into account the preservation of all competencies obtained during laboratory work.

 

Virtual analogue of 2009 year

The previous version of the virtual analogue of the subcritical assembly is a two-dimensional program written in Delphi, which allows changing the spacing of the fuel element lattice, fuel enrichment (which is impossible in a real subcritical assembly), fuel type, and measuring the axial distribution of the neutron flux density along the central axis. The values ​​of the neutron flux density, which are displayed to the user as a measurement result, both in the previous version of the virtual analogue of the subcritical assembly and in the virtual reality version, were obtained during the simulation of the subcritical assembly in the MCU program. 

A two-dimensional version of the virtual analog can be found here.

 

USWA in virtual reality

In 2019, a virtual analogue of a uranium-water assembly using virtual reality technologies was created in the framework of the joint project with Rosatom "Creation of virtual analogues of elements of nuclear facilities for personnel training".

A virtual analogue is a complex of interactive models that allow laboratory work to experimentally determine the dependence of the material parameter on the lattice spacing.

 

Laboratory work on a virtual Uranium-Water Subcritical Assembly can be carried out completely in accordance with real work on an experimental assembly.

 

 

Additional functionality

The virtual analog also provides additional opportunities for laboratory work:

• Measurement of radiation dose rate using a portable dosimeter;
• Measurement of the accumulated radiation dose during the laboratory work;
• Visualization of the distribution of the neutron flux in the uranium-water assembly;
• Visualization of the distribution of the radiation dose in the room.

Distribution of radiation dose in the assembly room

 

Distribution of the neutron flux in the assembly