Novel DGT Configurations for the Assessment of Bioavailable Plutonium, Americium, and Uranium in Marine and Freshwater Environments

Abstract

Plutonium, americium, and uranium contribute to the radioactive contamination of the environment and are risk factors for elevated radiation exposure via ingestion through food or water. Due to the significant environmental inventory of these radioelements, a sampling method to accurately monitor their bioavailable concentrations in natural waters is necessary, especially since physicochemical factors can cause significant temporal fluctuations in their waterborne concentrations. To this end, we engineered novel diffusive gradients in thin-film (DGT) configurations using resin gels, which are selective for UO 2 2+ , Pu(IV + V), and Am(III) among an excess of extraneous cations. In this work, we also report an improved synthesis of our in-house ion-imprinted polymer resin, which we used to manufacture a resin gel to capture Am(III). The effective diffusion coefficients of Pu, Am, and U in agarose cross-linked polyacrylamide were determined in freshwater and seawater simulants and in natural seawater, to calibrate these configurations for environmental deployments.

Passive Sampling Tool for Actinides in Spent Nuclear Fuel Pools

“…All reagents used were of analytical grade, from Sigma-Aldrich, Merck, or DGT Research (Lancaster, UK). The KMS-1 and IIP-Y 3+ DGT sampling configurations were synthesized as described by Chaplin et al 1 Diffusive polyacrylamide gels, membrane filters, and the cross-linker solution were purchased from DGT Research. Boric acid stock solution (BASS), based on 4000 ppm B (pH 4.5), was prepared according to the composition of SFP at a nuclear facility with whom we collaborated for the practical deployments of samplers.…”

“…The eluates from radiochemical separations were evaporated to dryness and electrodeposited on stainless-steel discs according to the procedure reported by Bajo et al 5 D from diffusion cell experiments was calculated using eq 1 (below), where is the D calculated at the temperature of experimentation. was then normalized to 25 °C using the Stokes–Einstein correction, as previously reported for these analytes according to eqs 2 – 4 of Chaplin et al 1 …”

“…Here, is the activity or mass of the analyte isotope in the resin-gel eluate; for sampler deployments includes an additional of 0.049 cm for each actinide, as reported for Pu by Cusnir et al 4 and Am by Chaplin et al; 1 t is the exposition time (s), and S is the surface area of the exposed filter membrane of DGT samplers.…”

“…Herein, we present a technical note which calibrates and evaluates the recently developed KMS-1 and IIP-Y 3+ DGT configurations 1 for use in borated SFP waters. In this work, we make the diffusion coefficients ( D ) available for the major actinides (U, Pu, Am, and Cm) in simulated SFP water based on diluted boric acid (H 3 BO 3 ).…”

“…We also extend the scope of the DGT technique to measure Cm using the IIP-Y 3+ DGT configuration. 1 This is important for SFP measures as Cm isotopes are significant α-emitting sources present in spent fuel.…”