Enlarge (credit: Bloomberg / Getty Images News) David Charles Hahn, who was nicknamed the “Radioactive Boy Scout,” received regular visits from the FBI for nearly a decade from 2005 through 2015, Ars has learned. Hahn, who was profiled by Harper’s Magazine in 1998 for his attempts to build a homemade breeder nuclear reactor in his mother’s backyard shed, passed away late last year in Michigan at the age of 39.