Determination of U, Pu and Am isotopes in Irish Sea sediment by a combination of AMS and radiometric methods

Samples from a marine sediment core from the Irish Sea (54.416 N, 3.563 W) were analyzed for the isotopic composition of uranium, plutonium and americium by a combination of radiometric methods and AMS. The radiochemical procedure consisted of a Pu separation step by anion exchange, subsequent U separation by extraction chromatography using UTEVA® and finally Am separation with TRU® Resin.Additionally to radiometric determination of these isotopes by alpha spectrometry, the separated samples were also used for the determination of 236U/238U and plutonium isotope ratios by Accelerator Mass Spectrometry (AMS) at the VERA facility.

► Investigation of Irish Sea sediment samples for their 236U/238U and 240Pu/239Pu isotopic ratios.
► The 236U/238U results are between (1.35–4.36) × 10−5 which indicate an anthropogenic contamination.
► The mean 240Pu/239Pu value along the core is 0.23 ± 0.04 and represents no weapons-grade Pu.
► Additional 241Am/243Am was measured via AMS and compared with alpha spectrometry.