Study of hydrogeology in the Mizunami Underground Research Laboratory Project; Numerical prediction of recovery behavior of groundwater environment during groundwater filling test and underground facility closure

Onoe, Hironori; Kimura, Hitoshi*

In this study, predictive simulations were conducted in order to understand recovery behavior of groundwater environment during groundwater filling test and underground facility closure. As a result of predictive simulations of groundwater filling test, difference of groundwater environment changes around the closure test drift according to groundwater filling volume was confirmed quantitatively. As a result of the simulations, groundwater environment changes at 10 years after underground facility closure could be estimated. And, it was shown that up-corning of deep saline water through drift and shaft was occurred if hydraulic conductivity of backfill material is higher than host rock.