Study of criticality safety and neutronic parameters of UO2 fuel in MTR research reactors using the MCNP4C code

• Re-cycling of the ETRR-2 reactor by UO2 fuel elements.
• Using two forms of the fuel material plate.
• Neutronic traps were increased from one neutronic trap to three neutronic traps.
• Neutronic parameters of the ETRR-2 reactor were calculated for the studied fuels.

The low enriched uranium UO2 fuel performance in MTR-22 MW reactor is investigated in this paper with One Neutronic Trap (ONT) and Three Neutronic Traps (TNTs) to increase the scientific utilization of the reactor. The MCNP4C code was used to estimate the criticality safety and the neutronic parameters of the MTR-22 MW before and after replacing the U3O8-Al original fuel by the UO2 one. The re-evaluated criticality safety parameters and the new neutronic characteristics of this reactor showed that the replacement of U3O8-Al Fuel Elements (FEs) by UO2 FEs would not significantly affect the neutronic characteristics of the MTR-22 MW as well as its criticality for both the ONT and the TNTs. This result leads to say that the replacement of U3O8-Al FEs by UO2 FEs will not affect the safety of the reactor.