Fifty one years ago today, just before 9pm on January 3rd 1961, 27-year old John A. Byrnes began lifting a control rod out of the SL-1 reactor located about 60 miles west of Idaho Falls, Idaho. The procedure Byrnes was supposedly attempting was a re-connection of the control rod to an automated servo mechanism. This would require that Byrnes pull the 88-pound rod four inches out of the reactor core. Instead Byrnes pulled the rod twenty six inches out of the core.
The SL-1 reactor had been renamed the Argonne Low Power Reactor (ALPR) the first of many designed to provide electrical power for remote posts. Pulling the control rod more than 20 inches out of the core was the central operation in a unpublished scuttle procedure for the ALPR-type reactors. One operator explained it: “If we were at a radar station and the Russians came. We’d yank it out.”
Once the central control rod was removed the reactor went “prompt critical” causing much of the coolant water to explosively vaporize. The twenty-six-thousand-pound reactor vessel jumped over nine feet in the air. Parts shot off the vessel as the steam sought escape; one part impaled one of three men (26-year-old Richard C. Legg) in the containment chamber. Steam shot out scalding the remaining men. 22-year-old Richard Leroy McKinley would survive until 11pm.
Investigation into Byrnes’s motivation suggests a possible suicide-murder involving an affair with one of the other operators and perhaps his wife with one of the other operators.
The bodies of the men were measured at 500 R/hr. They were buried in Arlington National Cemetery using special lead-lined coffins, sealed in concrete, placed in metal vaults, and given another concrete cover for extra safety.