Local and global trace plutonium contributions in fast breeder legacy soils.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33741911.
- Also identified by DOI 10.1038/s41467-021-21575-9 and PMC identifier 7979690.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Trace-level plutonium in the environment often comprises local and global contributions, and is usually anthropogenic in origin. Here, we report estimates of local and global contributions to trace-level plutonium in soil from a former, fast-breeder reactor site. The measured <sup>240</sup>Pu/<sup>239</sup>Pu ratio is anomalously low, as per the reduced <sup>240</sup>Pu yield expected in plutonium bred with fast neutrons. Anomalies in plutonium concentration and isotopic ratio suggest forensic insight into specific activities on site, such as clean-up or structural change. Local and global <sup>239</sup>Pu contributions on-site are estimated at (34 ± 1)% and (66 ± 3)%, respectively, with mass concentrations of (183 ± 6) fg g<sup>-1</sup> and (362 ± 13) fg g<sup>-1</sup>. The latter is consistent with levels at undisturbed and distant sites, (384 ± 44) fg g<sup>-1</sup>, where no local contribution is expected. The <sup>240</sup>Pu/<sup>239</sup>Pu ratio for site-derived material is estimated at 0.05 ± 0.04. Our study demonstrates the multi-faceted potential of trace plutonium assay to inform clean-up strategies of fast breeder legacies.