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TEPCO's Fukushima Daiichi nuclear power plant accident prompted extensive decontamination work. The decontaminated soil and incinerated ash generated by the process are scheduled for final disposal by March 2045 outside Fukushima Prefecture. The final disposal is unprecedented worldwide. Clarifying their acceptability will contribute to the final disposal of decontaminated soil and incinerated ash, as well as add knowledge about the perceived risk of low-concentration radioactive waste. A questionnaire survey was conducted to assess the psychological factors influencing final disposal acceptability. The results of the structural equation modeling demonstrated stable results, with risk perception decreasing acceptability, social benefits increasing acceptability, and personal benefits having limited impact. The initiative for the final disposal of decontaminated soil and incinerated ash can facilitate the reconstruction of Fukushima Prefecture after the disaster. Trust and intergenerational expectations are critical factors influencing the acceptability of this disposal. The responses were classified based on the relevance of moral norms using cluster analysis and moral foundations. The influence of each element on acceptability varied depending on the cluster. Trust was identified as the most influential factor in acceptability, regardless of the level of importance placed on moral norms. [Display omitted] • Psychological factors affecting the acceptance of final disposal were evaluated. • Factors included risk/benefit perception, trust and intergenerational expectations. • Structural equation modeling was conducted to evaluate the influences. • Respondents were classified based on their moral foundations by cluster analysis. • Trust emerged as an important factor regardless of the degree of moral foundations. [ABSTRACT FROM AUTHOR]

Radionuclides released and deposited because of the 2011 Fukushima Dai-ichi Nuclear Power Plant accident caused an increase in air dose rates in Fukushima Prefecture forests. Although an increase in air dose rates during rainfall was previously reported, the air dose rates in the Fukushima forests decreased during rainfall. This study aimed to develop a method to estimate rainfall-related changes in air dose rates, even in the absence of soil moisture data, in Namie-Town and Kawauchi-Village, Futaba-gun, Fukushima Prefecture. Moreover, we examined the relationship between preceding rainfall (Rw) and soil moisture content. The air dose rate was estimated by calculating the Rw in Namie-Town from May to July 2020. We found that the air dose rates decreased with increasing soil moisture content. The soil moisture content was estimated from Rw by combining short-term and long-term effective rainfall using half-live values of 2 h and 7 d and considering the hysteresis of water absorption and drainage processes. Furthermore, the soil moisture content and air dose rate estimations showed a good agreement with coefficient of determination (R 2 ) scores >0.70 and >0.65, respectively. The same method was tested to estimate the air dose rates in Kawauchi-Village from May to July 2019. At the Kawauchi site, variation in estimated value is relatively large due to the presence of water repellency in dry conditions, and the amount of 137Cs inventory was low, so estimating air dose from rainfall remained a challenge. In conclusion, rainfall data were successfully used to estimate soil moisture and air dose rates in areas with high 137Cs inventories. This leads to the possibility of removing the influence of rainfall on measured air dose rate data and could contribute to the improvement of methods currently used to estimate the external air dose rates for humans, animals, and terrestrial forest plants. [Display omitted] • Soil moisture content and air dose rate were estimated using effective rainfall. • Air dose rate changes were estimated using measured soil moisture content changes. • Magnitude of soil shielding effect was elevated by preceding rainfall. • This method might reveal influences besides rainfall on air dose rate changes. [ABSTRACT FROM AUTHOR]

Ingestion of edible wild mushrooms collected in areas contaminated with radiocesium released from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident may pose a risk of internal dose to their consumers. A species-specific aggregated transfer factor (T ag), which is calculated using radiocesium concentration in a wild mushroom species (Bq kg−1 wet mass [WM]) divided by the total concentration in the soil surface area (Bq m−2), would be a useful tool to estimate the dose from wild mushrooms by ingestion. In this study, we especially focused on the T ag data collected in 2016–2020 to use these values for a long-term dose assessment. We assumed that 137Cs concentrations after that year were almost the same, thus the soil-mushroom system would be in an apparent steady-state condition. In all, we could obtain T ag values of 137Cs in 62 edible wild mushroom species native to Japan. The geometric mean (GM) values were 1.5 × 10−3 m2 kg−1 WM using GMs of 13 saprobic type species and 5.0 × 10−3 m2 kg−1 WM using GMs of 21 mycorrhizal type species (N > 2). On average, the GMs of species-specific T ag values were 1.9 ± 0.9 times higher than those reported in a previous study of wild mushrooms made after the FDNPP accident, probably due to the different approaches for T ag calculation. • Aggregated transfer factor (T ag) of 137Cs from soil to wild mushroom was calculated. • Open source in-situ soil measurement data of 137Cs were used for T ag calculation. • T ag values obtained before and after the Fukushima accident did not change much. • 137Cs could be estimated for each mushroom species by using T ag values. [ABSTRACT FROM AUTHOR]