Reactivity temperature coefficients for the HEU and LEU fuel of the MNSR reactor

• Reactivity temperature coefficients of the MNSR using HEU and the LEU fuels were carried out.
• The FTC, MTC, and MDC were calculated using the GETERA code.
• The FTC average values were: −2.23E-03, −1.85E-02, −1.96E-02, −1.85E-02 mk/°C.
• The MTC average values were: −8.91E-03, −1.24E-04, −4.70E-03, 2.10E-03 mk/°C.
• The MDC average values were: −2.06E-01, −2.03E-01, −2.04E-01, −2.03E-01 mk/°C.

Analysis of the Reactivity Temperature Coefficients of the Miniature Neutron Source Reactor (MNSR) for normal and accidental conditions (above 45 °C) using HEU-UAl4 and the LEU: U3Si, U3Si2 and U9Mo fuel were carried out in this paper. The Fuel Temperature Coefficient (FTC), Moderator Temperature Coefficient (MTC), and Moderator Density Coefficient (MDC) were calculated using the GETERA code. The contribution of each isotope presented in the fuel cell was calculated for the temperature range of 20 °C–100 °C at the beginning of the core life. The average values of the FTC for the UAl4, U3Si, U3Si2 and U9Mo were found to be: −2.23E-03, −1.85E-02, −1.96E-02, −1.85E-02 mk/°C respectively. The average values of the MTC for the UAl4, U3Si, U3Si2 and U9Mo were observed to be: −8.91E-03, −1.24E-04, −4.70E-03, 2.10E-03 mk/°C respectively. Finally, the average values of the MDC for the UAl4, U3Si, U3Si2 and U9Mo were observed to be: −2.06E-01, −2.03E-01, −2.04E-01, −2.03E-01 mk/°C respectively. It's found also that the dominant reactivity coefficient for all types of fuel is the MDC.