Improved multi-group cross sections with resonance treatment for future applications involving minor actinides

• Resonance self-shielding treatment of minor actinides.
• Improved resonance interference calculations for effective cross sections.
• Validation of interference correction effect in self shielding calculations.
• Resonance treatment of minor actinides on multiplication factor.
• Comparison of results from a transport code nTRACER with MCNP.

In the future study for thorium reactors and minor actinide transmutation reactors, resonance self-shielding treatment for them becomes remarkable issue for criticality and isotope depletion. Resonance treatment for important minor actinides and other resonant absorbers has been carried out with subgroup method. The updated multi-group cross sections and subgroup data is replaced with existing multi-group library. The results from neutron transport code nTRACER with updated multi-group cross section library were compared with existing library and solutions from MCNP. The resonance interaction of uranium with important minor actinides has been accommodated through modified interference treatment by interference correction in subgroup method. The results for cross sections and multiplication factor for pin and assembly problems showed improvement from systematic resonance treatment for resonant absorber nuclides including 237Np and 243Am.