Uptake of Uranium from Seawater by Amidoxime-Based Polymeric Adsorbent: Field Experiments, Modeling, and Updated Economic Assessment

TLDR

Uranium recovery from seawater has been investigated for several decades to secure nuclear fuel for energy production. The study aimed to update the cost assessment of large‑scale uranium recovery from seawater using the ORNL amidoxime polymeric adsorbent. Field column experiments at PNNL employed the ORNL adsorbent packed in in‑line filters or flow‑through columns and compared its performance with a JAEA adsorbent under similar conditions. The ORNL adsorbent achieved a maximum uptake of 3.3 mg U g⁻¹ after 8 weeks—about three times the JAEA benchmark—and the updated production cost was estimated at $610 kg⁻¹ U, roughly half the JAEA cost.

Abstract

Uranium recovery from seawater has been investigated for several decades for the purpose of securing nuclear fuel for energy production. In this study, field column experiments have been performed at the Marine Sciences Laboratory of the Pacific Northwest National Laboratory (PNNL) using a laboratory-proven, amidoxime-based polymeric adsorbent developed at the Oak Ridge National Laboratory (ORNL). The adsorbent was packed either in in-line filters or in flow-through columns. The maximum amount of uranium uptake from seawater was 3.3 mg of U/g of adsorbent after 8 weeks of contact between the adsorbent and seawater. This uranium adsorption amount was about 3 times higher than the maximum amount achieved in this study by a leading adsorbent developed at the Japan Atomic Energy Agency (JAEA). Both adsorbents were tested under similar conditions. The results were used to update an assessment of the cost of large-scale recovery of uranium from seawater using the ORNL adsorbent. The updated uranium production cost was estimated to be reduced to $610/kg of U, approximately half the cost estimated for the JAEA technology.