@article{oai:repo.qst.go.jp:00079828,
 author = {Ni, Youyi and Guo, Qiuju and Huang, Zhaoya and Zheng, Jian and Li, Sixuan and Huang, Wenna and Bu, Wenting and Zheng, Jian},
 journal = {Chemosphere},
 month = {Apr},
 note = {In this study, the distribution and migration of 237Np and 239+240Pu in soils in the vicinity (<5 km) of Qinshan and Tianwan Nuclear Power Plants in China were studied. The 237Np and 239+240Pu concentrations in surface soils showed large spatial inhomogeneity. A remarkable 239+240Pu activity concentration (4.783 mBq/g) was observed in a surface soil near Qinshan NPP and stands for the ever reported highest value in the Chinese soils. The inventories of 239+240Pu in two Qinshan and Tianwan soil cores were estimated to be 128.8 Bq/m2 and 121.0 Bq/m2, respectively; while the 237Np inventories were 0.039 Bq/m2 and 0.035 Bq/m2 at these sites, respectively. The 240Pu/239Pu atom ratios in these soils indicated that the global fallout is the main source of Pu in these regions. However, the non-isotopic 237Np/239Pu atom ratio is not a sensitive and indicator for source identification. Furthermore, we conducted pilot study on the migration behaviors of 237Np and 239+240Pu in soil core at Qinshan site with the Convection-Dispersion Equation (CDE) model. The obtained apparent dispersion coefficients of 237Np (2.82±2.06 cm2/y) was 5 times higher than that of 239+240Pu (0.57±0.16 cm2/y), proving 237Np has stronger migration mobility than Pu isotopes. Finally, we predicted that with the increase of migration time, both 237Np and 239+240Pu activity concentration in the soil will gradually become homogeneous among different soil layers due to the dominant dispersion effects. This work is the first study on the distribution and migration of global fallout 237Np in Chinese soils.},
 title = {First study of 237Np in Chinese soils: source, distribution and mobility in comparison with plutonium isotopes},
 volume = {253},
 year = {2020}
}