The Ebay Code — Charles A. Salter

An experimental army nuclear reactor mysteriously explodes in 1961 and tons of nuclear debris are hauled away and buried.  Decades later some of this radioactive material goes missing. Brad Stout, a US Army major and expert in radiation defense at the military's premier radiation defense lab, is assigned to monitor sales of radioactive materials on eBay in an effort to prevent terrorists from getting their hands on items that can make dirty bombs. He notes unusual online auctions written in code to bypass eBay censors. As he begins to unravel the code, Brad uncovers a sinister plot to assassinate the president of the United States using the radioactive remains of the reactor. But when? Where? Pursued by enemy agents, can Major Stout solve the full mystery in time to save the president's life? Based in part on the true story of the little-known SL-1 nuclear disaster, this compelling dramatization will keep you guessing until the final page.