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Aosai, Daisuke*; Yamamoto, Yuhei*; Mizuno, Takashi; Ishigami, Toru*; Matsuyama, Hideto*
Colloids and Surfaces A; Physicochemical and Engineering Aspects, 461, p.279 - 286, 2014/11
Times Cited Count:10 Percentile:25(Chemistry, Physical)In studies of colloids in deep groundwater, a serious problem exists because the properties of the colloids are influenced by changes in the chemistry of groundwater upon exposure to the atmosphere and pressure release during sampling. Then, ultrafiltration technique, while maintaining in situ hydrochemical conditions was developed. As the result of the investigation using the method at the Mizunami underground Research Laboratory (MIU), different types of colloids consisting of inorganic and organic substances were observed and complex formation between the colloids and REEs was suggested. Furthermore, characteristic partitioning of REEs depending on colloids size was observed in complex natural environments without chemical disturbance. The current findings are useful for understanding migration of radionuclides.
Mukai, Masayuki; Tanaka, Tadao; Yukawa, Kazuhiko; Suryantoro*
Genshiryoku Bakkuendo Kenkyu, 12(1-2), p.41 - 51, 2006/03
To evaluate radionuclides migration through geologic media coexistent with colloids in groundwater, a model has been coded. To evaluate an applicability of four models to colloid transport through porous media, breakthrough curves (BTCs) from column experiments using sand and reddish soil have been analyzed. Instantaneous equilibrium model could not explain both timings of breakthrough and reach to C/C=1 concurrenyly, however 1st order kinetic reaction model successfully simulate them well. BTCs from the reddish soil column have a particular feature that shows step-wise rising pattern in response to alternately inflow of colloid. Both the instantaneous equilibrium, the 1st order kinetic reaction and filtration models could not simulate this feature, however a 1st order kinetic reaction with filtration capacity model reasonably simulates the feature. The model for colloid transport, given an important role as a part of colloidal migration model of radionuclide, has been validated on the basis of the laboratory experiments.
Hashimoto, Kazuyuki; Matsuoka, Hiromitsu
Radiochimica Acta, 92(4-6), p.285 - 290, 2004/07
Times Cited Count:1 Percentile:10.03(Chemistry, Inorganic & Nuclear)no abstracts in English
Chinju, H.*; Nagasaki, Shinya*; Tanaka, Satoru*; Sakamoto, Yoshiaki; Takebe, Shinichi; Ogawa, Hiromichi
Journal of Nuclear Science and Technology, 38(8), p.645 - 654, 2001/08
Times Cited Count:3 Percentile:27.1(Nuclear Science & Technology)no abstracts in English
; Murata, Eiichi*; Sawahata, Yoshikazu*; Saito, Akira*
JNC TN8430 2001-002, 43 Pages, 2001/02
Japan Nuclear Cycle Development Institute (JNC) is designing the Low level radioactive Waste Treatment Facility (LWTF) in the Tokai Reprocessing Plant (TRP). The low level liquid waste generated the TRP is separated salt (NaNO, etc) and radionuclide in liquid treatment process of LWTF. The process can get higher volume reduction than previous bituminization. Based on the engineering tests equal to the liquid treatment process of LWTF, the validity of operational condition in LWTF is evaluated. As the results, it is confirmed that all operational condition in the processes which is Iodine immobilization, Pre-filter filtration, Pre-treatment, Coprecipitation and Ultrafiltration are available.
Tanaka, Tadao; Ogawa, Hiromichi; Muraoka, Susumu
Materials Research Society Symposium Proceedings, Vol.663, p.1169 - 1177, 2001/00
no abstracts in English
Jitsukata, Shu*; *; ; ; Kurosawa, A.
JNC TN8410 2001-002, 66 Pages, 2000/12
It was required from IAEA to determine a small amount of plutonium in the high active liquid waste solutions (HALW) in the tokai reprocessing plant. High performance spectrophotometer (HPSP), which could be obtained lower detection limit than conventional spectrophotometer, is studied to be applied to the inspection and verification analysis by the IAEA. [Cold Test] Neodymium, showing an absorption peak near the absorption wavelength of plutonium (VI), was used as an alternative element to plutonium, in order to review the calculation method of the peak intensity. As a result, the three-point correction method was found to be simple and effective. [Hot Test] Plutonium nitrate solution was used the fundamental test of this method. Since the method is known to be influenced by acidity, suspended sludge and coexistent elements in a sample, each dependency was examined. It was found that measurement results varied about 14% at a nitric acid concentration of 2-4 mol/L. Sludge should be removed by filtration before the measurement. The effect of coexisting elements could be eliminated adjusting the optical balance between reference and sample beam intensity. In the case of measuring a low concentration plutonium solution sample, a ratio of the peak intensity to the background intensity (S/B ratio) is relatively small. Therefore a method should be improved the S/B ratio by analyzing the obtained spectra. Accumulated average method, moving average method and Fourier transform method was tested. The results showed that a combination of the accumulated average method and the moving average method was the optimum method for the purpose. Linearity of the calibration curve was found between 0-11 mgPu/L. Synthetic sample solution, which simulated the actual constituents of the HALW with plutonium showed a good linear relation at 0-11 mgPu/L. The detection limit for plutonium concentration was 0.07 mgPu/L. When the synthetic HALW solution containing plutonium was measured, the de
; ; *; *; *; *; *
JNC TN8440 2000-013, 179 Pages, 2000/04
The plutonium conversion development facility (PCDF) has been operated for 17 years and about 12 tons plutonium-uranium mixed oxide (MOX) powder has been converted since operation started in 1983. The first maintenance program for aging of apparatus was carried out from 1993 to 1994. The calcination-reduction fumace, liquid waste evaporator had been dismantled and renewed. The second maintenance program was carried out form 1998 to 1999. The microwave ovens, powder blender, ventilation control panel and so on were dismantled and renewed. Large volume radioactive wastes were generated during this maintenance such as the furnace, the filter casings and glove boxes. These wastes were too large to be packed into the waste container and these wastes were polluted by MOX powder unfixed on these surface. SO cutting and packing operation for these wastes and recovery of MOX powder from them were carried out. In this report, the method of this cutting and packing operation, the radioactive exposure to the operators in this operation, the estimation of nuclear material quantity migrated to filters, the evaluation of re-floating factor of radioactive material, etc. were discussed.
Sasamoto, Hiroshi; Yui, Mikazu; Savage, D.*; Bille, B.*
JNC TN8400 99-025, 32 Pages, 1999/06
Groundwater data used for modelling site or repository evolution need to be assessed for their quality and whether they are "fit for purpose", prior to utilization. This report discuss factors and issues which impinge upon the quality of such data. It is recommended that geochemical modelleres : (1)are aware of how groundwater samples were collected, whether during drilling, during hydraulic testing, or thereafter, by in-situ measurement, pumped from boreholes, or by pressurised sampler ; (2)are aware of what procedures (if any) were used to "correct" samples for drill fluid contamination and what errors were associated with those methods ; (3)are aware of whether samples were subject to de-pressurisation during sampling, and whether geochemical modelling techniques were applied to correct the compositions of samples for that process ; (4)request different measures of redox activity (e.g., electrode measurements of Eh, concentrations of different redox-sensitive aqueous species) to be applied to key groundwater samples to investigate the extent of redox equilibrium ; (5)are aware of how groundwater samples were filtered and preserved for off-site analysis ; (6)ensure that adequate methods of groundwater filtration ( 0.1m) and chemical analysis are applied to ensure accurate and reproducible analyses for dissolved aluminum at low levels of concentration (generally less than 0.2 mg/L) ; (7)are aware of elemental errors and detection limits in chemical analysis of groundwater samples and assess the quality of groundwater analyses via ion exchange balances and via a comparison of measured and calculated values for total dissolved solids contents. (8)ensure that detailed mineralogical analysis is carried out on rock samples from locations where key groundwater samples have been extracted.
Amano, Hikaru; Matsunaga, Takeshi; Nagao, Seiya; *; Watanabe, Miki*; Ueno, Takashi; Onuma, Yoshikazu*
Organic Geochemistry, 30, p.437 - 442, 1999/00
Times Cited Count:28 Percentile:52.71(Geochemistry & Geophysics)no abstracts in English
Amano, Hikaru; Hanzawa, Yukiko; Watanabe, Miki*; Matsunaga, Takeshi; Ueno, Takashi; Nagao, Seiya; Yanase, Nobuyuki; Onuma, Yoshikazu*
Proceedings of OECD/NEA Workshop on Evaluation of Speciation Technology, p.211 - 218, 1999/00
no abstracts in English
H.S.Shin*; J.H.Lee*; E.J.Hwang*; J.S.Shon*; G.N.Kim*; Matsuhashi, Shimpei; Kume, Tamikazu
Radiation Physics and Chemistry, 53(5), p.571 - 575, 1998/00
Times Cited Count:0 Percentile:0.01(Chemistry, Physical)no abstracts in English
Mineo, Hideaki; ; Nishizawa, Ichio; ; ; *; *; *; Takeshita, Isao
JAERI-Tech 96-050, 29 Pages, 1996/11
no abstracts in English
Yamaguchi, Isoo; Morita, Yasuji; ; ; ; ; *; *; ; Kubota, Masumitsu
JAERI-Tech 96-009, 51 Pages, 1996/03
no abstracts in English
Tanaka, Tadao;
Radioisotopes, 44(2), p.99 - 102, 1995/02
no abstracts in English