David Charles Hahn, who gained some notoriety in 1994 for attempting to build a homemade breeder nuclear reactor for a Boy Scout project in his mom's Michigan backyard shed, has died at the age of 39. He passed away on September 27, but his death did not draw much media attention until Monday.

Breeder reactors are a type of nuclear reactor that generate more fissile material than they consume. They have been researched extensively for decades, and a number have been built, but the approach has largely been abandoned.

Hahn’s travails were most notably chronicled in a 1998 article in Harper’s, which described his story in detail. (That article was later expanded into a book, The Radioactive Boy Scout.)

At the age of 17, Hahn wrote to numerous nuclear industry entities, including the Nuclear Regulatory Commission (NRC), posing as a high school science teacher. The Harper's article goes into some detail on his efforts. As Harper's wrote:

David hadn’t hit on the idea to try to build a breeder reactor when he began his nuclear experiments at the age of fifteen, but in a step down that path, he was already determined to “irradiate anything” he could. To do that he had to build a “gun” that could bombard isotopes with neutrons. … Again posing as a physics teacher, David managed to engage the agency’s director of isotope production and distribution, Donald Erb, in a scientific discussion by mail. Erb offered David tips on isolating certain radioactive elements, provided a list of isotopes that can sustain a chain reaction, and imparted a piece of information that would soon prove to be vital to David’s plans: “Nothing produces neutrons … as well as beryllium.” When David asked Erb about the risks posed by such radioactive materials, the NRC official assured “Professor Hahn” that the “real dangers are very slight,” since possession “of any radioactive materials in quantities and forms sufficient to pose any hazard is subject to Nuclear Regulatory Commission (or equivalent) licensing.” David says the NRC also sent him pricing data and commercial sources for some of the radioactive wares he wanted to purchase, ostensibly for the benefit of his eager students. “The NRC gave me all the information I needed,” he later recalled. “All I had to do was go out and get the materials.”

Hahn’s efforts were eventually halted after someone called the Clinton Township police on August 31, 1994—he had been stopped on suspicion of “stealing tires.” Authorities soon searched his car. Hahn warned that he had radioactive materials in the vehicle, and authorities proceeded to call in other agencies, including the Department of Energy, the Environmental Protection Agency, the NRC, and the FBI.

It took nearly a year from Hahn’s arrest until the backyard shed was dismantled and cleaned up as a Superfund site. Hahn later served four years in the United States Navy, including service aboard the USS Enterprise, a nuclear-powered aircraft carrier. He also briefly served in the United States Marine Corps and then returned back to his home state.

In 2007, some Ars forum members found an article that discussed Hahn's more recent efforts. Ars has filed public records requests with various federal agencies to learn more.

UPDATE Tuesday 12:32pm ET: We are still trying to ascertain the cause of death and will update this story when we have it.

The Macomb County Clerk's Office e-mailed Ars on Tuesday: "Unfortunately, the cause of death is still pending investigation."