TY - JOUR
T1 - Evaluation of Neutronic and Thermophysical Characteristics of Molten Salts Specialized for Long-Lived Fission Products Transmutation in a Fusion Reactor∗)
AU - KITASAKA, Taku
AU - SHISHIDO, Hiroki
AU - HASHIZUME, Hidetoshi
N1 - Funding Information:
The authors would like to thank N. Ohtori for advice on molecular dynamics simulations. This study was partly supported by JSPS KAKENHI Grant Number JP17H06231
PY - 2020
Y1 - 2020
N2 - This study proposes new molten salts, which are specialized for transmuting long-lived fission products (LLFP) using a helical fusion reactor FFHR-d1, as a neutron source. Molten salts are binary systems consisting of BeF2 and LLFP fluorides, such as BeF2–ZrF2, BeF2–PdF4, or BeF2–CsF. This study evaluates the effect of molten salts on the transmutation performance, and the amount of heat generated was evaluated by Monte Carlo-based neutron transport and burnup calculations. Therefore, when the transmutation area was fixed at 4% of the blanket system volume, the higher molar ratio of LLFP fluorides leads to higher transmutation performance. Also, the viscosity, specific heat, and thermal conductivity of BeF2–CsF were evaluated by molecular dynamics (MD) simulations. The heat transfer characteristics were evaluated by calculating the Prandtl number from MD simulation results. The Prandtl number of 50% CsF, which produced the lowest melting point (475°C), was evaluated to be 29.23, which was 60% larger compared to the Prandtl number of Flibe (LiF–BeF2) when the BeF2 molar ratio was 50%. This result suggested that the heat transfer performance was inferior to that of Flibe.
AB - This study proposes new molten salts, which are specialized for transmuting long-lived fission products (LLFP) using a helical fusion reactor FFHR-d1, as a neutron source. Molten salts are binary systems consisting of BeF2 and LLFP fluorides, such as BeF2–ZrF2, BeF2–PdF4, or BeF2–CsF. This study evaluates the effect of molten salts on the transmutation performance, and the amount of heat generated was evaluated by Monte Carlo-based neutron transport and burnup calculations. Therefore, when the transmutation area was fixed at 4% of the blanket system volume, the higher molar ratio of LLFP fluorides leads to higher transmutation performance. Also, the viscosity, specific heat, and thermal conductivity of BeF2–CsF were evaluated by molecular dynamics (MD) simulations. The heat transfer characteristics were evaluated by calculating the Prandtl number from MD simulation results. The Prandtl number of 50% CsF, which produced the lowest melting point (475°C), was evaluated to be 29.23, which was 60% larger compared to the Prandtl number of Flibe (LiF–BeF2) when the BeF2 molar ratio was 50%. This result suggested that the heat transfer performance was inferior to that of Flibe.
KW - BeF
KW - LLFP
KW - Monte Carlo method
KW - Prandtl number
KW - burnup calculation
KW - molecular dynamics
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U2 - 10.1585/PFR.15.2405077
DO - 10.1585/PFR.15.2405077
M3 - Article
AN - SCOPUS:85097519378
VL - 15
SP - 2405077-1-2405077-6
JO - Plasma and Fusion Research
JF - Plasma and Fusion Research
SN - 1880-6821
ER -