Authors:Kwang-Pill Lee, Keung-Shik Park, Duck-Won Kang, Yasuhiro Yamada, and Shin-ichi Ohno
The mechanism of the reduction reaction of lanthanide(III) ions by hydrated electrons in polar solvents has been investigated.
The theoretical rate constants for the reaction of hydrated electrons with a number of lanthanide ions have been calculated
using the energy gap laws of the charge shift reaction(D+−A→D−A+) and compared with experimental values. With these results, we have explained the large difference of the reaction rates
of lanthanide ions with hydrated electrons, which depend upon the kind of lanthanide ion. The calculated results agree almost
quantitatively with the experimental values.
Authors:Keung-Shik Park, Nak Kim, Hyung Woo, Kil Lee, Wan Hong, and Sang Chun
For the separation of rare-earth elements from steel, with a cation exchange resin, separation experiments were performed on NIST reference materials of SRM-363 and SRM-364. Iron, Na, Cr, Mn, Co, Cu, As, Mo, Sb and W were separated in 2M hydrochloric acid, five rare-earth elements, La, Ce, Pr, Nd and Sm and three other elements, Hf, Zr and Ba were separated using 8M nitric acid. Each element was determined by a single comparator method using two monitors, gold and cobalt.
Authors:Nak Kim, Keung-Shik Park, Hyung Woo, Kil Lee, Yoon Yoon, and Duk Kim
A radiochemical separation method using an anion exchange resin has been applied to 4N grade tungsten for determining U, Th and 4 other elements. While tungsten remained in the resin, Na, K and As were separated with 0.05M HCl and 1M HF and then U, Th and Cr were eluted with 1M HCl and 1M HF. The separation yield of neptunium (U) was influenced largely by the amount of thorium, but this influence could be neglected as the concentration of the thorium was below 0.5g/ml. The content of these elements were calculated by a single comparator method using monitors, gold and cobalt. The detection limits of U and Th are 4.0 and 1.2 ppb, respectively.
Authors:Kil-Oung Choi, Young-Seok Lee, Sun-Tae Hwang, Kwang-Pil Lee, and Keung-Shik Park
The manganese sulphate bath method is widely used for measurements of neutron source strength. In this study, the analytical
chemistry method based on the Inductively Coupled Plasma (ICP) spectrometry was used for examining the impurity contents of
MnSO4·H2O, to induce55Mn(n,γ)56Mn reactions. From the analytical results, mainly K, Co, and Zn as well as trace amounts of Cd, Li, etc., have turned out
to be the relevant impurities absorbing the neutrons and the fraction of neutron absorbed by the total impurities was determined
to be 1.37%.
Authors:Kwang-Pill Lee, Hyung-Gik Kim, Keung-Shik Park, Duck-Won Kang, and Eun-Hee Kim
The adsorption characteristics of carbon on a strong base anion and cation exchange mixed resin, Amberlite IRN-150 in OH+ and H− (1∶1) used in nuclear power plant, were investigated at 6, 30 and 50 °C at a concentration of carbon up to 0.02M. The expression
for the adsorption of carbon was well fitted to the Freundlich equation and the constants,k andn in the equation were deduced. Furthermore, we could explain that the adsorption capacity on the mixed resin increases with