Shutdown dose rate analysis with the Shift Monte Carlo radiation transport code and modular verification workflow

• Published in: Fusion engineering and design 2023-09, Vol.194 (1), p.113895, Article 113895
• Main Authors: Bae, Jin Whan, Kos, Bor, Biondo, Elliott
• Format: Article
• Language: English
• Subjects: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ITER; MCNP; ORIGEN; R2S; SDDR; Shift; Shutdown dose rate analysis
• ISSN: 0920-3796; 1873-7196
• DOI: 10.1016/j.fusengdes.2023.113895

Calculation of the shutdown dose rate is crucial for safe fusion reactor operations. The Rigorous-two-step (R2S) method is a method that requires connected neutron transport, activation, and gamma transport. Shift has integrated variance reduction with a deterministic solver Denovo, supports multiple geometry formats, and is scalable. These features make it an attractive transport solver choice for an R2S workflow. An R2S workflow for the Shift Monte Carlo code is developed and compared to the existing Oak Ridge National Laboratory Shutdown Dose Rate Code Suite (ORCS) workflow. Also, a Python framework for integrating two R2S workflows is developed to mix and match each step in the R2S workflow for improved collaboration and verification experience. Results show that the Shift-Denovo R2S workflow and the ORCS workflow calculate the shutdown dose rate of the ITER Shutdown Dose Rate benchmark problem with an average relative error of 2.285%. •Developed Shift Monte Carlo code for Shutdown Dose Rate calculation.•Comparison between two independent R2S workflows, using Shift and MCNP.•Integrated Python toolkit for dissecting and combining R2S workflow steps.•Evaluation of differences for each R2S step between two R2S workflows.