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Abstract  

A simultaneous sampling system for the speciation of atmospheric T and 14C has been developed. Firstly tritiated moisture together with all water vapor in air is adsorbed on Drierite after coagulation using an electric cooler. Then 14CO2 plus stable CO2 in the dried air is adsorbed on molecular sieve 4A. Elemental tritium gas (HT) plus hydrogen gas (H2) in the atmosphere along with H2 gas generated from electrolysis of groundwater which does not contain any T, are oxidized on Pd catalyst to water and adsorbed on molecular sieve 3A. Tritiated methane (CH3T) and 14CH4 plus stable methane in the atmosphere are oxidized on Pt catalyst to water and CO2 under 400 °C. Then, Drierite and molecular sieve 4A adsorb the oxidized T (HTO) and C-14 (14CO2), respectively. Tritium and C-14 in surface and soil air have been measured using this system

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Abstract  

Effective thermal conductivity of fireworks raw materials and their mixture have been measured by the temperature modulated DSC and the hot wire method, in order to predict spontaneous ignition properties precisely. As a result, an excellent linear correlation has been obtained between the density and the λe by the TMDSC method. Moreover, the low-density data by the hot wire method lie on the extrapolated point of the linear correlation. Thus, the λe within the ordinary limit of fireworks composition can be measured by the TMDSC method. Krupiczka’s estimation method shows a good agreement with the experimental values.

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Simulation of the atmospheric dispersion of 85Kr from a reprocessing plant over a coastal area

Performance examination of an emergency environmental radiation dose evaluation code system, SIERRA-II

Journal of Radioanalytical and Nuclear Chemistry
Authors: M. Takeyasu, T. Iida, H. Watanabe, M. Takeishi, and A. Yamamoto

Abstract  

The performance of the computer code system, SIERRA-II, for calculating the environmental radiation dose due to an accident was assessed over a coastal area, using the environmental monitoring data around the coastally located Tokai Reprocessing Plant (TRP) when 85Kr was discharged during its operation. The agreement within a factor of 5 between the calculated and observed air concentrations of 85Kr in areas of a few km from the TRP was achieved in 57% of the comparison data, disregarding the internal boundary layer. The mean fraction bias was −0.6, which meant a slight overestimation. According to the vertical profile of the atmospheric temperatures, the internal boundary layer was modeled with the SIERRA-II and the agreement became better than when the internal boundary layer was not considered.

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Abstract  

Liquid scintillation counting is the most popular method for tritium measurement, however, it takes much time and a lot of doing to distill off the impurities before mixing the sample water and liquid scintillation cocktail. We have investigated the possibility of an alternative method to the distillation. We have found out that the filtration can be an alternative to distillation for the environmental water samples before electrolytic enrichment.

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Abstract  

Capillary and skimmer interfaces in EGA-MS were compared by analysis of the carbon substances remaining in the hydrolysis products of aluminum alkoxides. Peaks with higher intensities were detected in the skimmer interface mode than those in the capillary interface mode. It was confirmed in particular that the skimmer interface is effective in increasing the sensitivity for species with higher mass, e.g. the evolved butyl group, as carbon substances remaining in the hydrolysis product of aluminum sec-butoxide.

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Abstract  

The radionuclide 67Cu was produced via the 68Zn(p,2p)67Cu reaction by irradiating enriched 68Zn targets with 70 MeV proton beam. Copper-67 was chemically separated from the zinc target by ion-exchange chromatography using Chelex-100 chelating ion-exchange resin. Procedure for recovery of the enriched 68Zn was developed. The target recovery yield of this method was evaluated to be more than 97%.

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Abstract  

The size distributions of 38Cl, 39Cl, 82Br and 84Br aerosols generated by irradiations of argon and krypton gases containing di-octyl phthalate (DOP) aerosols with 45 MeV and 65 MeV quasi-monoenergetic neutrons were measured in order to study the formation mechanism of radioactive particles in high energy radiation fields. The effects of the size distribution of the radioactive aerosols on the size of the added DOP aerosols, the energy of the neutrons and the kinds of nuclides were studied. The observed size distributions of the radioactive particles were explained by attachment of the radioactive atoms generated by the neutron-induced reactions to the DOP aerosols.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: S. Watanabe, Y. Iida, N. Suzui, T. Katabuchi, S. Ishii, N. Kawachi, H. Hanaoka, S. Matsuhashi, K. Endo, and N. Ishioka

Abstract  

Copper-64 was produced by the 64Ni(p, n)64Cu reaction using enriched 64NiO target. We investigated and compared the production yield of 64Cu for proton beams of various energies by using a thick target. Enriched 64Ni was recovered with high yield by simple procedures. Imaging studies using positron emission tomography (PET) and positron emitting tracer imaging system (PETIS) were performed. We obtained clear images in PET and PETIS studies. The results of this study indicate that 64Cu can be utilized as a biomedical tracer for the molecular imaging both in animals and plants.

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