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J. A. BERRY*; M. BROWNSWORD*; D. J. ILETT*; Linklater, C. M.*; Mason, C.*; TWEED, C. J.*
JNC TJ8400 2000-060, 60 Pages, 2000/02
JNC-TJ8400-2000-060.pdf:2.95MB
Batch sorption experiments have been carried out to investigate the sorption behaviour of plutonium onto basalt and sandstone from the appropriate rock-equilibrated waters under different redox eonditions. Redox Potentials in solution were controlled by the addition of two reducing agents and one oxidising agent. Thermodynamic chemical modelling was undertaken to interpret the results. The sorption models were based on iron oxide. They adequately reproduced the data for sorption of plutonium onto sandstone, but tended to underpredict sorption onto basalt.
Takachi, Kazuhiko; Taniguchi, Wataru
JNC TN8400 99-042, 68 Pages, 1999/11
The buffer material is expected to maintain its low water permeability, self-sealing properties, radionuclides adsorption and retardation properties, thermal conductivity, chemical buffering properties, overpack supporting properties, stress buffering properties, etc. over a long period of time. Natural clay is mentioned as a material that can relatively satisfy above. Among the kinds of natural clay, bentonite when compacted is superior because (1)it has exceptionally low water permeability and properties to control the movement of water in buffer, (2)it fills void spaces in the buffer and fractures in the host rock as it swells upon water uptake, (3)it has the ability to exchange cations and to adsorb cationic radioelements. In order to confirm these functions for the purpose of safety assessment, it is necessary to evaluate buffer properties through laboratory tests and engineering-scale tests, and to make assessments based on the ranges in the data obtained. This report describes the procedures, test conditions, results and examinations on the buffer material of dynamic triaxial tests, measurement of elastic wave velocity and liquefaction tests that aim at getting hold of dynamic mechanical properties. MWe can get hold of dependency on the shearing strain of the shearing modulus and hysteresis damping constant, the application for the mechanical model etc. by dynamic triaxial tests, the acceptability of maximum shearing modulus obtained from dynamic triaxial tests etc. by measurement of elastic wave velocity and dynamic strength caused by cyclic stress etc. by liquefaction tests.
; Yamazawa, Hiromi
Journal of Nuclear Science and Technology, 34(8), p.835 - 846, 1997/08
Times Cited Count：2 Percentile：23.04(Nuclear Science & Technology)no abstracts in English
; Yamazawa, Hiromi
Journal of Nuclear Science and Technology, 32(7), p.671 - 682, 1995/07
Times Cited Count：4 Percentile：43.23(Nuclear Science & Technology)no abstracts in English
; Yamazawa, Hiromi
JAERI-Research 95-016, 22 Pages, 1995/03
JAERI-Research-95-016.pdf:0.88MB
no abstracts in English
; Yamazawa, Hiromi
JAERI-Research 94-040, 40 Pages, 1994/11
JAERI-Research-94-040.pdf:1.39MB
no abstracts in English
and CeONakamura, Akio
Journal of Nuclear Materials, 201, p.17 - 26, 1993/00
Times Cited Count：18 Percentile：83.19(Materials Science, Multidisciplinary)no abstracts in English
*; *
PNC TN941 85-44, 75 Pages, 1985/03
In the analysis of a core expansion (or postdisassembly expansion) phase by the SIMMER-II code, it was shown that there exist various thermo-hydraulic phenomena available for mitigating effectively the mechanical energy released in a hypothetical core disruptive accident. To utilize SIMMER-II as a standard tool in future safety assessment, the experimental validation of the code is crucial especially on the energetics-mitigating effects. In this study, a series of simulated core expansion experiments performed at Purdue University was analyzed by SIMMER-II as the first effort of the code validation program in Japan. In the experiments, either the nitrogen gas at room temperature or the flashing water at high temperature was injected and expanded into the water pool simulating the outlet plenum of the reactor vessel (a 1/7-scaled model of the Clinch River Breeder Reactor vessel). In the analysis of the nitrogen expansion experiments, SIMMER-II could reproduce the experimentally measured slug impact time without adjusting input parameters. This means that the overall fluid-dynamics model of SIMMER-II is valid. In the flashing water expansion experiments, on the other hand, SIMMER did not reproduce the experimental data very well due to the presence of complex rate-limited processes including heat transfer and phase transiton. This discrepancy is ascribed to lack of modeling the entrainment phenomenon occurring at the interface of a vapor bubble. The effect of the entrainment is very important since the entrained cold liquid efficiently enhances the vapor condensation and hence reduces the slug kinetic energy. It was shown that this effect can be approximated by increasing the heat transfer coefficient between liquid components. Obviously, this result cannot be directly extrapolated to the reacor condition, but implys that the nominal SIMMER parameters are conservative from the energetics point of view because of underestimation of the vapor condensation. ...
Nakayama, Hiromasa; Katata, Genki*
no journal, ,
Dry deposition is important process of chemical material input of gaseous and particulate forms from the atmosphere into the terrestrial ecosystem near the ground surface in the planetary boundary layer. It is difficult to accurately estimate dry deposition amounts for such areas. First, we incorporate our particle dry deposition scheme into the loca-scale high-resolution atmospheric dispersion model and perform test simulations in comparison to indoor experiments. Next, we apply to the hilly-terrain forest in a field-site to analyze the impact of topography and forest structure to dry deposition. It is found that the model successfully simulated the maximum values at the edge of the forest and exponential decrease with a downwind distance from the edge as well as the experiments. Furthermore, for the field-site, the distribution of dry deposition shows a peak at the forest edge, rapidly decreases with a downwind distance from the edge. Although the local decrease is observed at the forest gap, that shows nearly constant within the canopy.
