Comparison of MC-based depletion codes used for radioactive inventories in proton beam accelerators
Accurate prediction of neutron yields and flux spectra is essential for assessing the radioactive inventory of irradiated components, structural materials, and targets/beam dumps used in proton accelerators. This evaluation plays a crucial role in planning decommissioning activities, waste management, and handling of active materials. MCNP, PHITS, and FLUKA Monte Carlo (MC) codes provide problem-dependent fluxes and spectra to their respective depletion modules, which performs depletion calculation and provide time-dependent material compositions, induced activities, decay heat, etc. Since the Monte Carlo codes utilize different physics models for particle-nucleus interactions for the proton beam energies above the maximum energy 200 MeV in available nuclear data libraries, variations in neutron yields, flux spectra, and consequently in radioactive inventories are inevitable. Additionally, differences in nuclear data used by different codes can further contribute to these variations.
This thesis proposes a comparative study of three depletion codes: ALEPH2 combined with MCNP code; DCHAIN integrated into the PHITS code; and the FLUKA depletion module. These codes are assessed based on the experimental benchmark data obtained with a 590 MeV proton beam impinging a copper (Cu) target of the Paul Scherrer Institute in Switzerland. This experimental benchmark is selected due to the similarity to the MYRRHA proton accelerator in terms of beam energy and also the target material composition.
By addressing discrepancies in calculation and the experimental data and understanding the impact of different physics models and nuclear data, the thesis will enhance the reliability of depletion codes used in proton accelerator applications.
Objectives
- Develop a PHITS and FLUKA inputs using the available MCNP code input developed for the experimental benchmark.
- Calculate, explore and understand the variations in neutron yields, flux spectra, and radioactive inventories resulting from different physics models employed by the Monte Carlo codes.
- Investigate the impact of differences in nuclear data utilized by ALEPH2, DCHAIN, and FLUKA on the accuracy of radioactive inventory predictions.
- Write a master thesis based on the findings.
Het vereiste minimumdiploma van de kandidaat
- Academic bachelor
De vereiste achtergrondkennis van de kandidaat
- Physics