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Tanaka, Tadao; Mukai, Masayuki; Li, Z.*; Li, S.*
JAERI-Conf 2003-010, p.142 - 149, 2003/09
An environmental migration test of Sr-85 was carried out in natural unsaturated loess zone at the field test site of China Institute for Radiation Protection, China, and the migratory mobility of Sr was observed during 2 years. As laboratory experiments, the migration experiment of Sr by a column system and the sorption experiment of Sr by a batch system were carried out by using the loess taken from the field test site. We discussed about applicability of sorption data determined from the laboratory experiments to evaluating the Sr migration behavior investigated at the field test site. The Sr migration behavior at the field test site could be expressed by the equilibrium sorption model using distribution coefficients determined from the laboratory experiments. This supports that the valid distribution coefficient for the evaluation of Sr migration in natural environment is predicted from the laboratory experiments.
Ogawa, Hiromichi; Tanaka, Tadao; Mukai, Masayuki; Maeda, Toshikatsu; Munakata, Masahiro; Matsumoto, Junko; Bamba, Tsunetaka; Li, S.*; Wang, Z.*; Li, Z.*; et al.
Nihon Genshiryoku Gakkai Wabun Rombunshi, 2(3), p.332 - 335, 2003/09
The filed migration test using TRU nuclide was carried out as a cooperative research project between JAERI and CIRP (China Institute for Radiation Protection). This report introduced the outline of the filed migration test and described the outline of the special number of Field Test on Migration of TRU-nuclide and main results as a summary report.
Tanaka, Tadao; Mukai, Masayuki; Munakata, Masahiro; Maeda, Toshikatsu; Ogawa, Hiromichi; Wang, Z.*; Li, S.*; Yang, Y.*; Zhao, Y.*
Nihon Genshiryoku Gakkai Wabun Rombunshi, 2(3), p.350 - 360, 2003/09
Migration data of 
Sr,
Np and 
Pu in natural aquifer were collected by a field test, which was performed in an aquifer at 30 m under ground surface of the field test site. Migration parameters for analysis of the results obtained the field test were measured by laboratory column tests and batch tests. Diffusion coefficient corresponding to water velocity was determined from the relationship between water velocity and diffusion length, which obtained from the column tests. Distribution coefficient was determined by considering confident ability of data, test conditions, and environmental conditions. One dimensional migration behavior of the radionuclides in aquifer, calculated by using the migration parameters obtained from the batch and column tests, agreed with the results obtained from the field test. It was confirmed that the migration behavior of alpha-nuclides could be evaluated by applying the conventional equation for evaluating the radionuclide migration and the migration parameters obtained from laboratory tests.
Tanaka, Tadao; Mukai, Masayuki; Maeda, Toshikatsu; Munakata, Masahiro; Matsumoto, Junko; Ogawa, Hiromichi; Bamba, Tsunetaka*; Wang, Z.*; Yang, Y.*; Zhao, Y.*
Proceedings of International Symposium on Radioecology and Environmental Dosimetry, p.179 - 184, 2003/00
Migration behaviors of stable strontium element and radioactive nuclide strontium 90 in natural aquifer were studied by a field test, which was performed in the aquifer loess zone at 30 m under the ground surface of the field test site of China Institute for Radiation Protection. The migration behavior of stable strontium was a little different from that of Sr. The difference was evaluated by applying the distribution coefficient considering Sr and coexistent ion concentrations. Migration behavior of radionuclide in natural environment has been generally demonstrated on field tests without radioactive tracers and/or large-scale column tests with radioactive tracers. Such tests seem to be valuable to improve reliability of the migratory evaluation.
; *
JNC TN8400 2001-010, 25 Pages, 2001/03
Performance assessment in geosphere for the JNC's 2nd progress report was based on nuclide migration calculation results by discrete fracture network model. The channel network model approximated from fracture network model with considering fracture connectivity was applied for nuclide migration analysis, since fracture network model had too large data to calculate nuclide migration. However, there are many options in the process of approximation from fracture network model to channel network model. In case of analyzing nuclide migration for above report, so-called "base case", one option was chosen from many options, arbitrarily. In this report, the sensitivity of these options to nuclide migration calculation results was studied. As a result, there was no significant impact to nuclide migration although connectivity of channel and flow characteristics of the model slightly changed among different options. Based on above studies, we concluded that an option used for the base case was appropriate.
*; *; *; *
JNC TJ8400 2000-006, 232 Pages, 2000/05
JNC-TJ8400-2000-006.pdf:7.75MB
In this research, simulations with some parameters which characterize ground water flow and the reliability evaluation for the expansion of the calculation method of groundwater flow were carried out by using the radionuclide transport computations in nearfield heterogeneous porous media. Concretely contents are follows: (1)With the series of calculation method for three-dimensional saturated/unsaturated groundwater flow and one-dimensional radionuclide transport. the computational analyses with the parameters used in JNC report in 2000 was carried out and the influence of the different input flux was evaluated. (2)The examination of the application for the different ways of inverse laplace transformation which is used in one-dimensional radionuclide tansport analysis code "MATRICS" was carried out. (3)The examination of the application of multi-element "MATRICS" (m-MATRICS) for radionuclide transport computations in nearfield heterogeneous porous media was carried out. (4)The series of calculation methods from three-dimensional saturated/unsaturated ground water flow simulation code to one-dimensional radionuclide transport simulation code was integrated.
*; *; *; *
JNC TJ8400 2000-005, 71 Pages, 2000/05
In this research, simulations with some parameters which characterize ground water flow and the reliability evaluation for the expansion of the calculation method of groundwater flow were carried out by using the radionuclide transport computations in nearfield heterogeneous porous media. Concretely contents are follows: (1)With the series of calculation method for three-dimensional saturated/unsaturated groundwater flow and one-dimensional radionuclide transport, the computational analyses with the parameters used in JNC report in 2000 was carried out and the influence of the different input flux was evaluated. (2)The examination of the application for the different ways of inverse laplace transformation which is used in one-dimensional radionuclide transport analysis code "MATRICS" was carried out. (3)The examination of the application of multi-element "MATRICS" (m-MATRICS) for radionuclide transport computations in nearfield heterogeneous porous media was carried out. (4)The series of calculation methods from three-dimensional saturated/unsaturated ground water flow simulation code to one-dimensional radionuclide transport simulation code was integrated.
Sawada, Atsushi; Ijiri, Yuji; *; Watari, Shingo
JNC TN8400 99-093, 58 Pages, 1999/11
This paper decribes the results of PA studies considering heterogeneous fracture characteristics, for the purpose of contributing for the performance assessment of the natural barrier system PA in H12 report (The second progress report on research and development for the Geological Disposal of HLW in Japan). In this study, 3-D discrete fracture network mode1 (DFN) and 1-D multiple pathways model is applied for 100m scale of rock block. Although nuclide release rate calculated by DFN are widely distributed among the realizations, it is shown that several tens realizations are enough number to understand the stochastic characteristics of the nuclide release. From the data uncertainty analysis, there are no significant effects for the nuclide retardation in fracture geometry parameters such as fracture radius, density and etc. 1-D multiple pathways model is developed with focusing on the heterogeneity of the transmissivity, which has a large effect to the nuclide retardation effects. The nuclide release rate calculated by using 1-D multiple pathways model approximates to the results of DFN. This result also shows that the relatively large fractures/faults that connects disposal tunnel and downstream faults have an important role for performance assessment in natural barrier system.
Ijiri, Yuji; ; *; Watari, Shingo; K.E.Web*; *; *
JNC TN8400 99-092, 91 Pages, 1999/11
JNC has been developed the performance assessment approaches for both fractured rock and porous rock. An equivalent continuum model is incorporated for solving the radionuclide migration in porous rock, while a discrete fracture network model is incorporated for solving the radionuclide migration in fractured rock (see more detail in Sawada et al. [1999]). This report describes the methodology, the data and the results of the performance assessment of porous rock. From the results of radionuclide migration analyses that were based on the hydrogeological properties obtained from the Neogene sedimentaly rock at the Tono mine, it was found that the release rate of selenium-79 and cesium-135 are dominant in porous rock. The sensitivity analyses using one-dimensional porous model revealed that hydraulic conductivity has more influences on the results than porosity does. In addition, it was found that smaller distribution coefficients of sandstone yield higher release rate than mudstone and tuff, and smaller distribution coefficients of saline water conditions yield higher release rate than fresh water conditions. The radionuclide migration in Neogene sedimentaly rock, where flow in rock matrix as well as in fractures are significant, was evaluated by superposing the results of porous model and fracture model. Since fracture model tends to yield more conservative results than porous model, it is obvious that the performance of Neogene sedimentary rock can be conservatively assessed by fracture model alone. The nuclide migration analyses performed in this report were based on the hydrogeological properties obtained at the depth between 20 meters and 200 meters frrom the ground surface. Therefore, it should be noted that the release rate at the depth of a future repository in Neogene sedimentary rock, 500 m, will be smaller than that shown in this report due to peemeability decrease from 200 m to 500 m.
Amano, Hikaru
Purazuma, Kaku Yugo Gakkai-Shi, 73(12), p.1360 - 1361, 1997/12
no abstracts in English
