Adsorption mechanisms and models of Sr, Np, Pu and Am in loess media (Joint research)

Tanaka, Tadao; Mukai, Masayuki; Maeda, Toshikatsu; Matsumoto, Junko; Ogawa, Hiromichi; Li, S.*; Wang, Z.*; Wang, J.*; Guo, Z.*; Zhao, Y.*

JAERI-Research 2002-034, 20 Pages, 2002/12

JAERI-Research-2002-034.pdf:1.1MB

Adsorption mechanisms and models of Sr(II), Np(V), Pu(IV) and Am(III) on the loess were investigated from their adsorption and desorption properties. The distribution coefficient of Sr and Np was 2 - 3 orders of magnitude smaller than that of Pu and Am. The adsorption of Sr and Np was mainly controlled by the ion exchange reaction. On the other hand, the adsorption of Pu and Am was mostly controlled by the selective chemical reactions with Fe and Mn oxyhydroxide/oxide and humic substances. On the basis of the experimental results, several types of adsorption models of the radionuclides, considering elemental concentrations, adsorption mechanisms and kinetics, were proposed for setting up the analytical systems of radionuclide migration in the loess media.

Improvement in production yield of Sr@C using nuclear recoil

Miyashita, Yuka*; Akiyama, Kazuhiko*; Hatsukawa, Yuichi; Kubuki, Shiro*

no journal, , 

To obtain an endohedral metallofullerenes with high specific radioactivity using nuclear recoil phenomena, many experiments have been performed so far. However, production yield of metallofullerene by nuclear recoil using high LET radiation was found to be very small because radiation damages to targeted fullerene molecule were not negligible. In order to increase the yield of radioactive metallofullerenes, it is very promising to employ the recoil of nuclear reaction by fast neutron from the viewpoint of reducing the radiation damage. In this session, we will report the synthesis of Sr@C using nuclear recoil of Sr(n,2n)Sr reaction by 14 MeV fast neutron. Mixture of C with strontium salts such as Sr(NO) and SrCO were employed for the target materials. These samples were irradiated by fast neutron in Fusion Neutronics Source at Japan Atomic Energy Agency. After the irradiation, CS, aniline, and HCl were passed through the irradiated samples on the filter to dissolve C, Sr@C, and strontium salts, respectively. The -ray from these solutions were measured by Ge detector. As a result, about 0.75 % of radioactivity was observed in the aniline solution from SrCO sample. This result strongly suggests that Sr@C was efficiently produced by fast neutron irradiation of SrCO/C target.