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-1,2-dichloroethylene decomposition in low-humidity air under electron beam irradiationSun, Y.*; Hakoda, Teruyuki; Chmielewski, A. G.*; Hashimoto, Shoji*
Radiation Physics and Chemistry, 68(5), p.843 - 850, 2003/12
Times Cited Count：8 Percentile：49.8(Chemistry, Physical)no abstracts in English
Hamahara, Kazuhiro*; Shigemitsu, Masahito*; Noriki, Shinichiro*; Fukuyama, Ryuji*; Aramaki, Takafumi; Otosaka, Shigeyoshi
Engan Kaiyo Kenkyu, 41(1), p.53 - 60, 2003/08
no abstracts in English
Fukumoto, Masahiro; Nishikawa, Yoshiaki*; Kagawa, Akio; Kawamura, Kazuhiro
JNC TN8400 2001-002, 23 Pages, 2000/12
JNC-TN8400-2001-002.pdf:0.55MB
The soluble organic compounds generated by radiological degradation of asphalt (
ray) were confirmed as a part of influence of the bituminized waste degradation in the TRU waste repository. Especially, the influence of the nitrate was focused on. As a result, the concentration of the soluble organic compounds generated by radiological degradation of asphalt (10MGy, ray which is correspond to absorbed dose of asphalt for 1,000,000 years) were lower (each formic acid : about 50mg/dm
, acetic acid : about 30mg/dm and oxalic acid : about 2mg/dm) than that of the formic acid, the acetic acid and the oxalic acid which Valcke et al. had shown (the influence of the organic at the solubility examination which uses Pu and Am). Moreover, the change in the concentration of TOC and the soluble organic compounds (formic acid, acetic acid and oxalic acid) is little under the existence of nitrate ion. That is, the formic acid and acetic acid which can be organic ligands were generated little by oxidative decomposition of asphalt in the process that nitrate ion becomes nitrite ion by radiation. The influence of the soluble organic compounds by the radiological degradation of the asphalt ( ray) on adsorption and solubility by the complexation of radionuclides in the performance assessment can be limited.
*; Sato, Haruo; *
JNC TN8400 99-059, 59 Pages, 1999/10
Organic acids in groundwater are considered to form complexes and increase the solubility of radionuclides released from vitrified waste in a high-level radioactive waste (HLW) repository. To ivestigate whether the solubility of samarium (Sm) is influenced by organic substances, we measured Sm solubility in the presence of different organic substances and compared those values with results from thermodynamic predictions. Humic acid (Aldrich) is commercially available and soluble organic matter originated from bentonite were used as organic substances in this study. Consequently, the solubility of Sm showed a tendency to apparently increase with icreasing the concentration of humic acid, but in the presence of carbonate, thermodynamic predictions suggested that the dominant species are carbonate complexes and that the effect of organic substances are less than that of carbonate. Based on total organic carbon (TOC), the increase of Sm solubility measured with humic acid (Aldrich) was more significant than that in the case with soluble organic matter originated from bentonite. Since bentonite is presumed to include also simple organic matters of which stability constant for forming complexes is low, the effect of soluble organic matter originated from bentonite on the solubility of Sm is eonsidered to be less effective than that of humic acid (Aldrieh). Experimental values were compared with model prediction, propsed by Kim, based on data measured in a low pH region. Tentatively we calculated the increase in Sm solubility assuming complexation with humic acid. Trial calculations were carried out on the premise that the complexation reaction of metal ion with humic acid is based on neutralization process by 1-1 complexation. In this process, it was assumed that one metal ion coordinates with one unit of complexation sites which number of proton exchange sites is equal to ionic charge. Consequently, Kim's model indicated that carbonate complexes should be dominant ...
Nakata, Kotaro*; Hasegawa, Takuma*; Tomioka, Yuichi*; Tanaka, Yasuharu*; Hama, Katsuhiro; Iwatsuki, Teruki
no journal, ,
The technology development of groundwater dating has been carried out as a part of CRIEPI-JAEA collaboration. The carbon-14 in the organic matter dissolved in groundwater is used to estimate groundwater age. The estimated age is almost same as the age that estimated by the He-4 in groundwater. This suggested that the age estimation by carbon-14 in organic matter can be useful tool to enhance the reliability of the data on groundwater age.
Jeon, H.; Ogawa, Hiroshi*; Otosaka, Shigeyoshi
no journal, ,
Radiocarbon content of marine dissolved organic carbon (DO
C) can provide useful information on how organic carbon is produced, transported, and ultimately sequestered in the ocean interior. We conducted research to present the first set of full-depth profiles for DOC along a transect from the central South Pacific Ocean to Chukchi Sea. In order to measure radiocarbon contents of seawater samples, they should be processed with a specific preparation system consists of the custom quartz reactor, dedicated vacuum line and UV lamp followed by radiocarbon counting with an accelerator mass spectrometer. As the first step of the study, we have developed the irradiation procedure using a low-pressure Hg lamp and an oxidation catalyst. We present here how the system is progressing as well as what radiocarbon study in the central Pacific Ocean means for better understanding of oceanic carbon cycle.
