Yang-Soon Park

Infrared Spectra of Uranium Oxides Measured by ATR-FTIR

The infrared spectra of uranium oxides (UOx) of various O/U ratios (x = 2–2:667 in UOx) were measured by using ATR-FTIR in order to investigate the applicability of ATR technology to the characterization of uranium oxides or nuclear fuel. The samples of uranium oxides (UOx) were prepared by heating UO2 powder in air atmosphere followed by weighing to determine the gains by oxygen. X-ray diffraction (XRD) patterns for the same samples of infrared spectra were measured to get information on their phases on uranium oxides (UOx) with increasing x. The measured characteristic bands from UOx samples could be assigned well by referring to the spectra reported in the literature and comparing with the diffraction patterns measured. The relationship between absorbance and O/U ratio (x) was determined. We discussed about using it for the O/U ratio estimation of uranium oxides of unknown composition. It was confirmed that ATR technology for infrared spectroscopy can be useful for the studies of radioactive materials that are difficult to handle using conventional methods.

Crystallographic characterization of irradiated U-10Zr and U-10Zr-5Ce metallic fuels

Crystal structures of irradiated U-10Zr and U-10Zr-5Ce metallic fuels at approximately 2.9 at.% burnup were probed by micro-X-ray diffraction, which identified the presence of UO2 and α-U phases in both fuels. Analysis of the lattice parameters of α-U phase region using Pawley refinement showed α-U lattice expansion in the b-axis direction, which was correlated with the irradiation growth of orthorhombic α-U. Furthermore, no FCCI and rim structure were observed in both irradiated metallic fuels.

Dissolution of vanadium pentoxide using microwave digestion system for determination of vanadium by ICP-AES

Dissolution procedure of vanadium pentoxide, which is widely used as a catalyst for production of sulfuric acid or an oxide reaction of the numerous organic compounds, was investigated. Reagent of vanadium pentoxide was completely dissolved in aqua regia--HF solution, but plate type of vanadium pentoxide sample was not clearly dissolved with mixed acids. Thus, in order to establish the dissolution procedure for plate type of vanadium pentoxide, the solubility of vanadium pentoxide was investigated through comparison of acid treatment-fusion and microwave digestion methods. The optimized acid for dissolution of vanadium compound was found to be mixing acids of aqua regia, and HF. Acid-fusion and microwave digestion methods have a similar property in the solubility of vanadium compound, but the latter was more quick and convenient procedure. The content of vanadium pentoxide was found to be using an inductively coupled plasma atomic emission spectrometer after dissolution of a sample with the microwave digestion system.