The National Nuclear Security Administration announced last week that it helped to remove 50 kilograms (111 pounds) of highly enriched uranium from Ukraine in the latter half of December. The material in now in secure storage in Russia. “[This] is a major milestone that brings us one step closer to achieving President Obama’s goal of securing all nuclear material around the world within four years,” said NNSA Administrator Thomas D’Agostino. Ukraine has pledged to relingquish all of its HEU by 2012. Back in May, NNSA assisted in the transfer of 56 kilograms from Ukraine to Russia. On Dec. 22, NNSA announced that the last HEU in Serbia left that nation for Russia. NNSA said it has now assisted with the disposition of 3,085 kg. of HEU and plutonium—enough material to make more than 120 nuclear weapons.
We looked back on the past 12 months to find the stories that resonated the most with you, our audience, and these 10 topped the list. Maybe you missed one the first time around, or perhaps you’d like to revisit a favorite.