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Suzuki, Satoru; Sato, Haruo
JNC TN8410 2001-028, 36 Pages, 2002/03
JNC-TN8410-2001-028.pdf:1.81MB
For a safety assessment of the high-level radioactive waste disposal, effective diffusion coefficients (D
) of radionuclides in bentonite have been accumulated by the through-diffusion method. It has been found recently that experimental results on Ds for several cations (cesium and strontium) by the fairly standard experimental method in JNC differ from those previously reported in several papers. Discrepancy can be considered to be due to different design of diffusion cell and system. In order to confirm influences of the experimental design on cation diffusivities in bentonite, a flow-through diffusion system was developed and several diffusion experiments were conducted.As a result, magnitude of D and its salinity dependence were relatively different between the standard and flow-through diffusion system. Since the latter system can control boundary conditions of the experiment more strictly than the standard method, we can conclude that the flow-through diffusion system provide correct results. In addition, we apply this flow-through diffusion system to a modification of controlling boundary condition during the experiment and to the diffusion experiment under controlled temperature.
; Miura, Akihiko; ;
JNC TN8410 99-043, 135 Pages, 1999/10
All result of chemical analysis and operators observation suggest non-chemical mechanism raised the filling temperature of the bituminized product at the incident. We, Tokai reprocessing plant safety evaluation and analysis team, performed the experiment using laboratory scale extruder and viscosity measurement to explain the high temperature of mixture. The result of the experiment using laboratory scale extruder showed that the phenomena of salt enrichment and salt accumulation oceured and they raised mixture temperature at the decreased feeed rate. These phenomena depend on the feed rate and they have large contribution of heat transportation and rise of operational torque due to the friction between screw and mixture. Based on the experiment result and all information, we investigated the operation procedure, operational records and machine arrangement to try to explain the behavior of the mixture in the extruder. Judging from each torque and temperature behavior, we succeeded in explaining a sequential behavior in the incident. It is estimated that mixture temperature was raised by physical heat generation in the extruder and this report explains each operation, investigated result and estimated event sequences.
Shigetome, Yoshiaki; ; ; Miura, Akihiko; Sato, Yoshihiko; Koyama, Tomozo
JNC TN8200 99-001, 128 Pages, 1999/07
None
; ; ; Isozaki, Tokuju;
PNC TN8450 93-004, 144 Pages, 1993/06
Generally speaking, two kinds of water plumes which have different temperature, salinity and so on are not easily mixturred and have special boundary. So, it is possible to predict ocurrence of special boundary of sea water from observation of temperature, salinity of sea water. Not only marine environmental monitoring such as radioactivity analysis of sea water, sea-bed sediment, marine products but also observation of water current, water direction, surface and ventical observation of water temperature, salinity and so on in Tokai coastal area are carried out with some observation instruments by Environmental Protection Section, Tokai Works, PNC. The results of vertical observation from 1990 to 1991 are recorded in this report.
Endo, Takashi*; Ishidera, Takamitsu; Terashima, Motoki; Tachi, Yukio
no journal, ,
To evaluate the colloid filtering function by compacted bentonite, colloidal stability tests and through-diffusion tests of dendrimer, a dendritic macromolecule, were carried out under high saline conditions. As a result, dendrimer can allow to evaluate the colloid filtering function of compacted bentonite under the high saline condition which has been difficult by conventional method.
Uchiyama, Shogo*; Matsushima, Ryotatsu; Koshigoe, Koki; Sato, Fuminori; Arai, Tsuyoshi*
no journal, ,
no abstracts in English