Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Iwatsuki, Teruki; Onoe, Hironori; Ishibashi, Masayuki; Ozaki, Yusuke; Wang, Y.*; Hadgu, T.*; Jove-Colon, C. F.*; Kalinina, E.*; Hokr, M.*; Balvn, A.*; et al.
JAEA-Research 2018-018, 140 Pages, 2019/03
DECOVALEX-2019 Task C aims to develop modelling and prediction methods using numerical simulation based on the water-filling experiment to examine the post drift-closure environment recovery processes. In this intermediate report, the results of Step 1 (Modelling and prediction of environmental disturbance by CTD excavation) are summarized from each of the research teams (JAEA, Sandia National Laboratories, Technical University of Liberec). Groundwater inflow rates to the tunnel during the excavation, hydraulic drawdown, and variation of chlorine concentration at monitoring boreholes in the vicinity of the tunnel were chosen as comparison metrics for Step1 by mutual agreement amongst the research teams. It is likely to be possible to foresee the scales of inflow rate and hydraulic drawdown based on a data from the pilot borehole by current simulation techniques.
Soler, J. M.*; Landa, J.*; Havlov, V.*; Tachi, Yukio; Ebina, Takanori*; Sardini, P.*; Siitari-Kauppi, M.*; Eikenberg, J.*; Martin, A. J.*
Journal of Contaminant Hydrology, 179, p.89 - 101, 2015/08
Times Cited Count:39 Percentile:81.5(Environmental Sciences)Matrix diffusion is a key process for radionuclide retention in crystalline rocks. An in-situ diffusion experiment in granite matrix was performed at the Grimsel Test Site (Switzerland). Several tracers (HTO, Na, Cs) were circulated through a borehole and the decrease in tracer concentrations was monitored for 2.5 years. Then, the borehole section was overcored and the tracer profiles in the rock were analyzed. Transport distances in the rock were 20 cm for HTO, 10 cm for Na and 1 cm for Cs. The dataset was analyzed with diffusion-sorption models by different teams using different codes, with the goal of obtaining effective diffusivities (De) and rock capacity factors. There was a rather good agreement between the values from different teams, implied that De and capacity factors in the borehole damaged zone are larger than those in the bulk rock. However, HTO seems to display large discrepancies between measured and modeled results.
Soler, J. M.*; Landa, J.*; Havlov, V.*; Tachi, Yukio; Ebina, Takanori*; Sardini, P.*; Siitari-Kauppi, M.*; Martin, A. J.*
Materials Research Society Symposium Proceedings, Vol.1665, p.85 - 91, 2014/09
Matrix diffusion is a key process for radionuclide retention in crystalline rocks. An in-situ diffusion experiment in granite matrix was performed at the Grimsel Test Site (Switzerland). Several tracers (HTO, Na, Cs) were circulated through a borehole and the decrease in tracer concentrations was monitored for 2.5 years. Then, the borehole section was overcored and the tracer profiles in the rock were analyzed. Transport distances in the rock were 20 cm for HTO, 10 cm for Na and 1 cm for Cs. The dataset was analyzed with diffusion-sorption models by different teams using different codes, with the goal of obtaining effective diffusivities (e) and rock capacity factors. There was a rather good agreement between the values from different teams, implied that e and capacity factors in the borehole damaged zone are larger than those in the bulk rock. However, HTO seems to display large discrepancies between measured and modeled results, which have to be investigated in more detail.
Soler, J. M.*; Landa, J.*; Havlov, V.*; Tachi, Yukio; Ebina, Takanori*; Sardini, P.*; Siitari-Kauppi, M.*; Martin, A.*
Nagra NAB 12-53, 80 Pages, 2013/02
An in-situ long-term diffusion (LTD) experiment was performed at the Grimsel Test Site (Switzerland). Tracers, HTO, Na, Cs, were continuously circulated through a packed-off borehole and the tracer concentrations in the solution was monitored for 2.5 years. Subsequently, the borehole section was overcored and the tracer profiles in the rock analyzed. The drop in activity for Cs in the solution was much pronounced. Transport distances were about 20 cm for HTO, 10 cm for Na and 1 cm for Cs. The dataset was analyzed with diffusion-sorption models by different teams using different codes, with the goal of obtaining effective diffusion coefficients () and rock capacity () values. There was a rather good agreement between the values from different teams, implied that and values in the BDZ are larger than those in the bulk rock. However, HTO seems to display large discrepancies between measured and modeled results, which have to be investigated in more detail.