Nuclear madness in Idaho

When the SL-1 nuclear reactor exploded in Idaho releasing a radioactive plume and killing three workers, a local paper reported the accident on page 12. That was 1961. Today some residents of Idaho are so worried about the nuclear accident 8000 kilometers away that they’re buying potassium iodide pills.

According to a history by Susan Stacey: "Editorial comment in Idaho and other newspapers categorized the SL-1 accident as a regrettable mishap, an inevitable occurrence if society were to accrue the benefits of a new technology." Today experts argue about whether the thick concrete containment around Fukushima Daiichi’s reactor vessel is safe enough and residents of inland American states worry about nuclear radiation from the accident. But the low-powered SL-1 boiling water reactor in Idaho had no containment. It was designed to be light weight — a prototype for reactors that could be shipped to the Arctic Circle to power remote military radar stations (pdf).

During the 1950s the US military looked to nuclear power as a practical way to solve problems. One problem was how to extend the range of its bombers. It sounds outrageous today, but the air force had plans to power aircraft using nuclear reactors. As a General Electric engineer, told Congress, a nuclear powered aircraft would be "limited in range only by sandwiches and coffee for the crew".

General Electric was one of a number of contractors engaged on the military’s aircraft nuclear propulsion program. At the National Reactor Testing Station (NRTS) in Idaho, GE’s engineers tested a nuclear power plant that sucked air directly into the reactor with the exhaust streaming out of a pair of specially modified jet engines. To test this ‘direct cycle’ engine, GE needed an outdoor test pad. According to Stacey:

Contaminated air could not be allowed to blow out the nozzle indoors—or near work areas. Rather, the reactor-cum-engine traveled back and forth between an assembly area and the test pad, a distance of a mile and a half. A man driving a shielded locomotive hauled a dolly carrying the eighty-ton assembly on four-rail tracks. At the test pad, the engine connected to a "coupling station"where the exhaust was filtered, went up a 150-foot stack, and was released to the open air (pdf).

Eventually GE engineers succeeded in running the turbojet engines without any help from chemical fuel. Stacey writes:

… the exhaust releases affected territory beyond the GE fence. Each time the jets operated, argon and other constituents of the air passing through the reactor became radioactive. Fuel elements occasionally ruptured or melted, discharging fission products. Some tests imitated accidents by deliberately blocking the flow of air to fuel elements, which also caused releases.

With contaminated exhaust being vented directly into the air, tests were limited to times when weather conditions made the tests less risky. According to Stacey the air force resented these restrictions and tried to have them relaxed.

At the time there seemed to be remarkably little concern about the testing. In 1960 Associated Press reporter Vern Hauglan described the tests without mentioning the risk of contamination. A local Idaho paper, the Lewiston Morning Tribune ran the story under the headline: "Plenty of elbow room available for test of nuclear plane."