Graph model under grey and unknown preferences for resolving conflicts on discharging Fukushima nuclear wastewater into the ocean

Abstract

Ten years after the Fukushima nuclear accident, on April 13, 2021, the Japanese government announced the discharge of nuclear wastewater into the Pacific Ocean starting from the late 2022 or early 2023. The implementation of this decision would harm the local and global marine ecology because of the radioactive substances in the nuclear wastewater, which has also triggered strong opposition from the Japanese people and neighboring countries. The discharge of nuclear wastewater is a complicated process. In the context of the COVID-19, options of decision makers (DMs) must take into consideration existing global uncertainty, potentially leading to a slew of uncertain outcomes. A novel grey and unknown preference framework of the graph model for conflict resolution (GMCR) was proposed in this study to resolve the conflict of discharging nuclear wastewater in the ocean. Four forms of unknown preferences were defined for different grey stability definitions fully considering consider the possibility of choosing unknown results by DMs and increasing the diversity of equilibrium results. The equilibrium results the other alternative methods to discharge or continue to store nuclear waste are more conducive to the development of various DMs, and the consultation and cooperation of all DMs would ensure effective conflict resolution.