Elutions of ^99mTc and ^113mIn have been performed subsequently with 10 mL of 0.9% NaCl solution and 10 mL of 0.1 M HCl solution, respectively, from 6-tungstocerate(IV) chromatographic column loaded with 0.54 MBq ⁹⁹Mo and 0.45 MBq ¹¹³Sn, using alumina-column filter in the case of ^99mTc. Radionuclidic purity of both eluates was ≥ 99.99%. Elution yields of 72.5±5.8% and 62.2±3.7%, and radiochemical purities of 96.9±1.0% (as ^99mTcO₄^-) and 88.4±2.5% (as ^113mIn³⁺) have been obtained for ^99mTc and ^113mIn, respectively. Al and W impurities in the ^99mTc and ^113mIn eluates, respectively, were found to be within the accepted limits, whereas no Ce impurities were detected in both eluates. Also trials have been carried out on a similar system to obtain mixed ^99mTc-^113mIn eluates from 6-tungstocerate column with different ^99mTc/^113mIn ratios using 0.9% NaCl-HCl eluents of different pH values. To separate ^99mTc and ^113mIn from each other, these mixed eluates were passed through a column of hydrous zirconium oxide which was then eluted with 10 mL of 0.9% NaCl solution and 15 mL of 0.1 M HCl solution, respectively. No W, Ce, or Zr impurities were detected in the ^99mTc and ^113mIn eluates obtained in these trials.

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To elucidate the environment of sedimentation in the Scotia and Ross Seas in the Antarctic Ocean during the period from upper Pleistocene to the present, sediments from the seas were investigated by ⁵⁷Fe Mössbauer spectroscopy, instrumental neutron activation analysis, and X-ray absorption near-edge structure. In Mössbauer spectra of Scotia Sea sediment, a specific doublet peak (isomer shifts of 0.57–0.59 mm s^-1, quadrupole splitting of 1.70–1.83 mm s^-1) was observed, suggesting the generation of primary glauconite by detailed speciation. In contrast, sediment cores from the Ross Sea and another sea area around Antarctica had no specific peak in Mössbauer spectra. Concentrations of iron and other elements in both sediments hardly fluctuated, that is, sedimentation matter in the Scotia Sea sediments containing iron species was not affected by the origin of specific iron species but by factors such as early-stage diagenesis.

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Uranium-gadolinium mixed oxides of four different compositions, (U_1-y Gd_y) O_2±x (y = 0.1, 0.2, 0.5, and 0.8), were synthesized. Single-phase fluorite structure was observed for the compositions (U_1-y Gdy) O_2±x (y = 0.1, 0.2, and 0.5). The room temperature lattice constants measured for (U_0.9 Gd_0.1) O_2.02, (U_0.8 Gd_0.2) O_2.00, and (U_0.5 Gd_0.5) O_1.98 are 0.5463, 0.5454, and 0.5433 nm, respectively. Heat capacity measurements in the temperature range 298 – 800 K were carried out using a differential scanning calorimetry. Considerable anomalous increases in the heat capacity values were observed for compositions (U_1-y Gd_y) O_2±x with y = 0.1, 0.2, and 0.5. The heat capacity values of (U_0.9 Gd_0.1) O_2.02, (U_0.8 Gd_0.2) O_2.00, and (U_0.5 Gd_0.5) O_1.98 at 298 K are 63.5, 61.1, and 65.7, respectively. Thermal expansion characteristics of (U_0.9 Gd_0.1) O_2.02, (U_0.8 Gd_0.2) O_2.00, and (U_0.5 Gd_0.5) O_1.98 were studied using a high temperature X-ray diffraction in the temperature range 298 – 1973 K.

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A mini review on the electrochemical applications of room temperature ionic liquids (RTIL) in nuclear fuel cycle is presented. It is shown that how the fascinating properties of RTIL can be tuned to deliver desirable application in aqueous and non-aqueous reprocessing and in nuclear waste management.

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Marine environments have been extensively contaminated by plutonium as a result of global fallout due to atmospheric nuclear-weapons testing. Knowledge of the levels and behavior of plutonium in marine environments is necessary to assess the radiological and ecological effects of plutonium. Such analytical techniques as radiochemical analysis, α-spectrometry, and mass spectrometry have been developed to analyze the plutonium in seawater over the past five decades. Because of complex chemical properties (e.g. high reactivity to particles), plutonium in the ocean exhibits more complicated behavior than other long-lived anthropogenic radionuclides, such as ¹³⁷Cs. In the present study, I reviewed the research history of plutonium in the ocean, including spatial and temporal changes of plutonium levels and distributions, and its oceanographic behavior.

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