Early stages, but current state of the art involves putting fabric out that captures the uranium passively. [1]

> Mining of underground uranium has environmental challenges not encountered with extracting it from the oceans. And Wai says the fibers, which have affinity for more heavy metals than just uranium, can likely be used one day to clean up toxic waterways themselves. He says the fibers have potential to extract vanadium, an expensive metal used in large scale batteries, from the oceans instead of mining it from the ground.

[1] https://www.pnnl.gov/news/release.aspx?id=4514

Yes, filtering ocean water for material is a well known technique. You need a massive throughput of ocean water for a small output and you also filter salts, other metals, polymers, and sea life. You must further refine those materials to get the stuff you want. You also change the ph of the filtered water in a way that would be disastrous if reinjected, and you consume filter media quickly. That all adds up to a huge waste and massive ecological damage.its simply not practical at scale.

I'm curious why you think deploying some of these fabrics would change the pH of the ocean? There are geological processes which replenish dissolved uranium in the ocean per the article I linked. I haven't seen any particular waste or sustainability concerns. The nice thing about uranium is that it's so incredibly energy dense that you don't really need to pull out all that much. I'm not ready to be so defeatist.

I defer to the researcher.

> "We have chemically modified regular, inexpensive yarn, to convert it into an adsorbent which is selective for uranium, efficient and reusable," said Chien Wai, president of LCW Supercritical Technologies. "PNNL's capabilities in evaluating and testing the material, have been invaluable in moving this technology forward."