2020 年 55 巻 4 号 p. 239-249
Monthly samples of atmospheric dust and depositions were collected at monitoring stations in the area surrounding Higashidori Nuclear Power Station. 7Be, 210Pb, and gross α and β radioactivity were measured to understand the effect of the nuclear power station on the surrounding environment and the amounts of air radiation and radionuclides in this area. The seasonal variation patterns of the 7Be and 210Pb atmospheric concentrations were similar and both had two peaks. The coefficients of determination of gross α and β radioactivity and 210Pb atmospheric concentration were high, suggesting that the contribution of 222Rn radioactive decay products was large for both types of radioactivity. The coefficients of determination of the 7Be and 210Pb deposition fluxes were high, and the total deposition velocity of both 7Be and 210Pb showed a seasonal variation pattern that had major peaks in summer and winter. However, the coefficient of determination of the 7Be total deposition velocity and monthly precipitation was higher than that of the 210Pb total deposition velocity, which suggests that precipitation was a more important factor for the deposition flux of 7Be than for 210Pb.
