Spatially resolved measurements of plutonium isotopes in environmental particle samples (MC-ICP-MS)

Spatially resolved measurements of plutonium isotopes in environmental particle samples (MC-ICP-MS)

The knowledge of chemical and isotopic compositions of nuclear materials, is of particular importance to nuclear forensics and nuclear safeguards. In the 20th century, large amounts of Pu were released into the natural environment as a result of stratospheric nuclear weapon tests.

A most commonly used and well-established technique for Pu isotopic analysis is alpha spectrometry. However, the vast majority of environmental samples have low activities and concentrations, for this type of samples the measurement time of several days or even weeks are often required. Measurements using the MC-ICP-MS offer easier sample preparation, relatively low costs and much shorter analysis time. When combined with a laser ablation introduction system, a sample’s inherent isotopic and elemental information as well as heterogeneity can all be revealed.

This study coupled a Nu Plasma HR instrument with a solid state laser, for spatially resolved Pu isotope ratio measurements of micro-samples (i.e. radioactive fuel particle clusters embedded in a soil matrix) emitted during the Chernobyl accident and sampled in the vicinity of the Chernobyl nuclear power plant in 1992.

The measured Pu isotopic ratios displayed in the plot are in good agreement with the expected ratios over the Chernobyl reactor core. The Daly detectors and full-size discrete dynode multipliers on the Nu Plasma instrument offer superior capability in the measurement of small beams, making Nu Plasma the instrument of choice for precise, accurate and spatially resolved actinide isotopic determination.

Data source: Stefanie Konegger-Kappel, Thomas Prohaska, Analytical and bioanalytical chemistry, January 2016, Volume 408, Issue 2, 431–440