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Kai, Takeshi; Yokoya, Akinari*; Fujii, Kentaro*; Watanabe, Ritsuko*
Hoshasen Kagaku (Internet), (106), p.21 - 29, 2018/11
It is thought to that the biological effects such as cell death or mutation are induced by complex DNA damage which are formed by several damage sites within a few nm. As the prediction of complex DNA damage at an electron track end, we report our outcomes. These results indicate that DNA damage sites comprising multiple nucleobase lesions with a single strand breaks can be formed by multiple collisions of the electrons within 1 nm. This multiple damage site cannot be processed by base excision repair enzymes. Pre-hydrated electrons can also be produced resulting in an additional base lesion over a few nm from the multi-damage site. This clustered damage site may be finally converted into a double strand break. These DSBs include another base lesion(s) at their termini that escape from the base excision process and which may result in biological effect. Our simulation is useful to reveal phenomena involved in radiation physico-chemistry as well as the DNA damage prediction.
Fujii, Kengo*; Ochi, Kotaro; Obuchi, Atsushi*; Koike, Yuya*
Journal of Environmental Management, 217, p.157 - 163, 2018/07
Times Cited Count:35 Percentile:77.62(Environmental Sciences)After the Fukushima Daiichi-Nuclear Power Plant accident, environmental recovery was a major issue because a considerable amount of municipal solid waste incineration (MSWI) fly ash was highly contaminated with radioactive cesium. In this study, MSWI fly ash was sampled in Fukushima Prefecture, and the physicochemical properties of radioactive cesium in MSWI fly ash were evaluated by particle size classification and the Japanese leaching test No. 13 (JLT-13). The results obtained from the classification of fly ash indicated that the activity concentration of radioactive cesium and the content of the coexisting matter (i.e., chloride, potassium, and sylvite) temporarily change in response to the particle size of fly ash. X-ray diffraction results indicated that water-soluble radioactive cesium exists as CsCl because of the cooling process and that insoluble cesium is bound to the inner sphere of amorphous matter.
Mezawa, Tetsuya; Mochizuki, Akihito; Miyakawa, Kazuya; Sasamoto, Hiroshi
JAEA-Data/Code 2018-001, 55 Pages, 2018/03
Japan Atomic Energy Agency has been conducting "geoscientific study" and "research and development on geological disposal" in the Horonobe Underground Research Laboratory (URL) for safe geological disposal of high-level radioactive waste. Geochemical parameters of groundwater pressure, pH, and oxidation-reduction potential in the deep groundwater has been continuously monitored with monitoring systems which were developed in the Horonobe URL Project. This report presents the physico-chemical parameters of groundwater which have been obtained by the monitoring systems installed at the 140 m, 250 m and 350 m gallery. The data obtained until March 31, 2017 was summarized along with related information such as the specifications of boreholes and the excavation of the URL.
Iwase, Masanori*
JNC TJ8400 2000-063, 78 Pages, 2000/03
This study is aimed at controlling oxidation reaction of molten metal by ash in incineration systems, and at positively utilizing the oxidation reaction for decontamination of slag. In this year, in order to investigate physico-chemical properties of mixed fused salt containing alkali sulfates, with special focus on the behaviour of oxygen anion in the melts, Cu / Cu redox equilibrium experiments were carried out. Among the effect of various parameters on Cu / Cu ratio in binary and ternary alkali sulfate melts, the effect of partial pressures of oxygen and SO was mainly investigated in the study. Variation in Cu / Cu ratio were presented as the function of partial pressures of oxygen and SO, respectively. Possible thermodynamic interpretation were made on the experimental results. In addition, the dissolution of CrO in mixed alkali sulfates were also investigated as a first step to elucidate the mechanism of hot corrosion. With this investigation, an important finding was obtained that the solubility of CrO for melts with same average ionic radius, in other words, oxygen ion activity, were essentially identical under constant temperature and atmosphere.
*; Shingu, Kazuki*; Takahashi, Eiichiro*; Nakajima, Toshihide*; Yamashita, Mitsugu*; *; *
PNC TJ7187 97-002, 586 Pages, 1997/11
None
Hoken Butsuri, 22, p.189 - 207, 1987/00
no abstracts in English
Maekawa, Fujio; Matsuda, Hiroki; Meigo, Shinichiro; Sasa, Toshinobu; Miyahara, Shinya*; Arita, Yuji*; Ohdaira, Naoya*
no journal, ,
To assess physicochemical composition of spallation products in Lead-Bismuth Eutectic (LBE) alloy which was to be used as a spallation neutron target and coolant materials of Accelerator Driven nuclear transmutation Systems (ADS), inventories of spallation products in an LBE loop of J-PARC ADS Target Test Facility (TEF-T) were evaluated.
Miyahara, Shinya*; Ohdaira, Naoya*; Arita, Yuji*; Sasa, Toshinobu; Maekawa, Fujio; Matsuda, Hiroki; Meigo, Shinichiro
no journal, ,
Representative spallation product elements in a lead-bismuth eutectic (LBE) loop in the ADS Target Test Facility (TEF-T) were selected. Chemical compounds of the elements and their concentrations which can be formed in the LBE were evaluated by one point equilibrium calculation by using the integrated thermodynamic calculation system Thermo-Calc.