Formation mechanism of deep groundwater at the Xinchang site of high-level radioactive waste geological disposal in China

The formation mechanism of deep groundwater is a key issue for the safety assessment of the high-level radioactive waste repository. The circulation characteristics and age of deep groundwater at the Xinchang site were characterized. The results show that the permeability of the deep parts of the faults at the site is low and the scale is small. Deep groundwater did not undergo deep circulation. The 14 C age of the deep groundwater was approximately 13.2 ka, and the deep groundwater circulation renewal rate was very slow. Therefore, the hydrogeological conditions at the site are beneficial to the selection of the site as a repository.