U.S. and Belgian officials have signed an agreement to install radiation detection equipment at Antwerp, one of Belgium's busiest seaports, to check for hidden shipments of fissile material, the two nations announced today. Antwerp will be the latest port to receive such equipment under the Megaports Initiative, which is run by the Energy Department's National Nuclear Security Administration. Placing radiation detection devices at overseas ports could prevent groups like al Qaeda from smuggling a nuclear bomb into the United States,...