A simple correction method for isobaric interferences induced by lead during uranium isotope analysis using secondary ion mass spectrometry

Research progress on the analysis and application of radioactive hot particle

Radioactive hot particle is the particulate form of nuclear material that exists in the environment. The U, Pu, Am, Cs, and other radionuclides isotope in the hot particle contain abundant and accurate fingerprint information, such as the origin and age of the nuclear material. The acquisition and analysis of the key information in the hot particle can be equivalent to the analysis of bulk nuclear material, which could directly reflect the real situation of nuclear activities. Therefore, the single particle analysis of hot particles has become an irreplaceable key technology in nuclear safeguards inspection. The rapid identification, screening, locating, and accurate isotope analysis of hot particles from a large number of particles dispersed in environmental media or on the surface of other materials are one of the most important research field in nuclear emergency. In this review, the research process of the analytical methods for hot particles in the last decade was summarized, including the physical character of hot particles, and the techniques of localization, screening, and extraction of hot particles. Furthermore, we also focused on the mass spectrometry technology for the analysis of hot particle. The advantages and disadvantages of the most used mass spectrometry were summarized. Finally, the research trend for hot particle analysis methods was proposed.

Progress of energy-related radiochemistry and radionuclide production in the Republic of Korea

The field of radiochemistry in the Republic of Korea has expanded greatly over the last three decades to meet the rapid growth of technological demands in various areas such as nuclear energy and nuclear technologies for human health and environmental protection. Major research activities, which were initially centered at the Korea Atomic Energy Research Institute (KAERI), have gradually spread to major universities and the commercial sector. In this review, progress and recent research trends in nuclear and radiochemistry in Korea are summarized. The main research outcomes achieved by KAERI scientists are highlighted, with emphasis on basic actinide chemistry in nuclear fuel cycles, the radioanalytical chemistry of various radionuclides from radioactive waste and the environment, and medical radionuclide production. In addition, recent efforts to promote radiochemical education and future perspectives are briefly outlined.

Determination of the isotopic composition of single sub-micrometer-sized uranium particles by laser ablation coupled with multi-collector inductively coupled plasma mass spectrometry

RATIONALE

A multi-collector inductively coupled plasma (MC-ICP) mass spectrometer coupled to a UV ns-laser ablation (LA) system was used to measure uranium isotopic ratios (²³⁴ U/²³⁸ U, ²³⁵ U/²³⁸ U and ²³⁶ U/²³⁸ U) in single uranium particles of various sizes and isotopic compositions, including home-made sub-micrometric natural uranium particles of narrow size distribution (415 ± 60 nm).

METHODS

The LA-ICP mass spectrometer was operated in wet plasma conditions thanks to simultaneous injection of the laser aerosol and water vapor through a desolvating nebulizer. The isotopic ratios were corrected for mass bias and gain factors between detectors. The ²³⁶ U/²³⁸ U ratios were also corrected for the presence of ²³⁵ U hydrides and tailing of the ²³⁸ U⁺ peak.

RESULTS

²³⁶ U/²³⁸ U ratios were successfully measured in micrometer-sized particles from the NBS U050 certified standard material with a ²³⁶ U/²³⁸ U ratio of ~5 × 10^-4 . The analysis of 77 natural uranium sub-μm-sized particles yielded a very good trueness with respect to the expected ²³⁴ U/²³⁸ U and ²³⁵ U/²³⁸ U ratios, while the measurement errors for single particles ranged from -2.7% to +2.1% for ²³⁵ U/²³⁸ U and from -17% to +33% for the ²³⁴ U/²³⁸ U ratios. Their relative combined standard uncertainties ranged from 3.3% to 32.8% and from 0.4% to 4.0% for ²³⁴ U/²³⁸ U and ²³⁵ U/²³⁸ U ratios, respectively. In addition, extremely low detection limits, in the attogram range, were achieved.

CONCLUSIONS

This study demonstrates that coupling of a ns-laser ablation system with a MC-ICP mass spectrometer allows measurements of the isotopic composition in natural uranium particles of a few hundreds of nm with very good trueness, average combined standard uncertainties of ~1% for ²³⁵ U/²³⁸ U ratios and 12% for ²³⁴ U/²³⁸ U ratios, and detections limits of a few ag for minor isotopes.