Uranium in seawater

Tamada, Masao

One ton of seawater contains 3.3 mg uranium. Total weight of the uranium in seawater is 4.5 billion tons which equals 75,000 times of annual uranium consumption in the nuclear plant all over the world. The uranium adsorbent with high mechanical strength has been successfully synthesized by radiation-induced graft polymerization. This uranium adsorbent was evaluated in the sea areas of Aomori and Okinawa, Japan. At Aomori, 1 kg uranium as yellow cake was collected by soaking the adsorbent cloths. To reduce the recovery cost, a braid type adsorbent was developed. By using new braid type adsorbent, 1.5 g-U/(kg-adsorbent) was achieved after 30 days' soaking in Okinawa. The attainable cost is estimated at 25,000 yen/kg-U.