TY - GEN
T1 - Development of a passive reactor shutdown device for prevention of core disruptive accidents in fast reactors
T2 - 2021 28th International Conference on Nuclear Engineering, ICONE 2021
AU - Morita, Koji
AU - Liu, Wei
AU - Arima, Tatsumi
AU - Arita, Yuji
AU - Kawase, Koharu
AU - Sato, Isamu
AU - Matsuura, Haruaki
AU - Sekio, Yoshihiro
AU - Sagara, Hiroshi
AU - Kawashima, Masatoshi
N1 - Funding Information:
This work was supported by MEXT Innovative Nuclear Research and Development Program in Japan. Special thanks to Dr. Yasushi Tsuboi of Toshiba Energy Systems & Solution Corp. We are deeply grateful to Dr. Hiroshi Endo for collaboration on the early stages of this work.
Publisher Copyright:
© 2021 by ASME.
PY - 2021
Y1 - 2021
N2 - After the Fukushima NPP accident in 2011, it has become increasingly important for reactor safety design to consider design measures to prevent the occurrence of severe accidents. In this study, a new subassembly-type passive reactor shutdown device is proposed to enhance the diversity and robustness of prevention measures for core disruptive accidents in sodiumcooled fast reactors. The proposed device contains pins with a fuel material that is kept in the solid state during normal operation but melts into the liquid when its temperature exceeds a prescribed value under the accidents. When a ULOF (unprotected loss of flow) or UTOP (unprotected transient overpower) accident occurs, the device can provide large negative reactivity passively by the relocation of liquefied device fuel into the lower plenum region of the pins by gravitation alone in a short time. The reactor, in which part of usual fuel subassemblies is replaced with the proposed devices, becomes subcritical before driver fuels are damaged, even if ULOF or UTOP transient occurs. In the present study, candidate materials for device fuel such as metallic alloy and chloride, optimum device pin structure for liquefied fuel relocation, and nuclear and thermal-hydraulic characteristics of the device-loaded core under accident conditions will be mainly investigated to demonstrate engineering feasibility of the proposed device. This paper describes the project overview and discusses preliminary results on nuclear requirements for negative reactivity to be inserted for reactor shutdown under expected device conditions.
AB - After the Fukushima NPP accident in 2011, it has become increasingly important for reactor safety design to consider design measures to prevent the occurrence of severe accidents. In this study, a new subassembly-type passive reactor shutdown device is proposed to enhance the diversity and robustness of prevention measures for core disruptive accidents in sodiumcooled fast reactors. The proposed device contains pins with a fuel material that is kept in the solid state during normal operation but melts into the liquid when its temperature exceeds a prescribed value under the accidents. When a ULOF (unprotected loss of flow) or UTOP (unprotected transient overpower) accident occurs, the device can provide large negative reactivity passively by the relocation of liquefied device fuel into the lower plenum region of the pins by gravitation alone in a short time. The reactor, in which part of usual fuel subassemblies is replaced with the proposed devices, becomes subcritical before driver fuels are damaged, even if ULOF or UTOP transient occurs. In the present study, candidate materials for device fuel such as metallic alloy and chloride, optimum device pin structure for liquefied fuel relocation, and nuclear and thermal-hydraulic characteristics of the device-loaded core under accident conditions will be mainly investigated to demonstrate engineering feasibility of the proposed device. This paper describes the project overview and discusses preliminary results on nuclear requirements for negative reactivity to be inserted for reactor shutdown under expected device conditions.
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U2 - 10.1115/ICONE28-64099
DO - 10.1115/ICONE28-64099
M3 - Conference contribution
AN - SCOPUS:85117823036
SN - 9784888982566
T3 - International Conference on Nuclear Engineering, Proceedings, ICONE
BT - Computational Fluid Dynamics (CFD); Verification and Validation; Advanced Methods of Manufacturing (AMM) for Nuclear Reactors and Components; Decontamination, Decommissioning, and Radioactive Waste Management; Beyond Design Basis and Nuclear Safety; Risk Informed Management and Regulation
PB - American Society of Mechanical Engineers (ASME)
Y2 - 4 August 2021 through 6 August 2021
ER -