The first fatal nuclear reactor accident in American history happened at a research station in Idaho in 1961—and is still the subject of debate and controversy.
"Hidden History" is a diary series that explores forgotten and little-known areas of history.
In the aftermath of the Second World War, the United States fell in love with the atom. The bombs at Hiroshima and Nagasaki had ended the most destructive war in human history, but they had also unlocked the promise of virtually unlimited energy that would be cheap, cheap, cheap.
The first nuclear reactors had been built as part of the wartime Manhattan Project for the urgent purpose of producing plutonium for atomic bombs, but it had already been recognized that they could also be used to produce electricity. So, to implement this new miraculous marvel, the Atomic Energy Commission (AEC) was established in January 1949, with the mandate to develop atomic energy for civilian use. The Atomic Age, it was hoped, would usher in a new era of unprecedented prosperity and plenty.
Commercial companies like General Electric and Westinghouse wanted in with what they assumed would be a bonanza, and several new designs for civilian nuclear reactors appeared. But even these corporate giants did not have the resources to build these prototypes and to evaluate which of them were viable and which would be discarded. That would fall to the AEC. And so, in 1949, construction was begun on an enormous new industrial facility, on 400,000 acres of empty lands around an old naval weapons proving ground near Idaho Falls, where new reactor ideas could be built and tested in safety without the dangers of exposing population or farmland to the hazards of radiation. It was dubbed the National Reactor Testing Station.
The first prototype to be completed was known as EBR-1, which started operations in December 1951. Experimental Breeder Reactor Number 1 had been designed to use uranium fuel to produce electricity, while at the same time producing plutonium as a by-product, which could then be extracted and put back into the reactor as additional fuel. The breeder reactor would be a sort of perpetual motion machine, constantly making its own new fuel supply. On its first test run, the EBR-1 successfully lit a string of four incandescent light bulbs. It was the first “peaceful” nuclear reactor.
Others designs soon followed, and by 1961 there were over 20 different reactors at the facility. One of these was the SL-1. Designated as a “Stationary Low-Power Reactor”, this was a very small design, intended to be air-transportable, with a planned output of 3 megawatts which was intended to serve as a mobile and modular power source. The Pentagon in particular was interested in this concept—they wanted to use it as a portable electricity generator in remote military bases, such as Arctic early-warning radar stations. The SL-1 was designed for up to 59 highly-enriched uranium fuel rods in its core and was intended to last for at least three years before requiring refueling. The prototype was first powered up in August 1958 and underwent several series of test runs. In testing, the reactor was ordinarily loaded with 40 fuel rods and five control rods.
Just before Christmas 1960, the SL-1 was shut down for the holidays. Eleven days later, on January 3, 1961, three technicians were assigned the routine task of starting the reactor back up again for a new series of tests. Two of these men, John Byrnes and Richard McKinley, were Army specialists, and the third, Richard Legg, was a Navy Seabee electrician.
During the start-up process, however, something went drastically wrong …
Shortly after 9 that night, alarms began ringing in the complex’s fire station, indicating an emergency in the SL-1 building. A team of seven firefighters raced to the scene. When they arrived, however, they saw no flames, no smoke, and no indications of trouble, aside from radiation alarms inside the building. Although the firefighters were garbed in anti-radiation suits, they were not really concerned, since low-level radiation releases which set off the alarms were a fairly common occurrence. Indeed, there had already been a false alarm earlier that day.
However, as they entered the building, they could not find any trace of the three nuclear technicians. At first, the rescuers assumed that the crew had left the building because of the radiation alarms, but a quick search outside found nothing. When they re-entered the building with Geiger counters, they found levels of radiation that were unsafe for prolonged exposure, and they knew something was wrong. Finding the control room empty, they cautiously made their way towards the reactor room, but as the radiation readings continued to climb, the firefighters decided to leave the building and call for help. Two military doctors arrived, and together they all re-entered the building and made their way into the reactor dome, where technicians had access to the top of the reactor core.
The first person they found was Byrnes, lying on the floor near the panel that operated the reactor’s control rods. He was barely conscious. Nearby, lying motionless next to the reactor core, was McKinley. The third operator, Legg, was nowhere to be seen. By now several other personnel had gathered outside the building, and five volunteers carried the two fallen technicians out of the building on stretchers. (Two of these volunteers would have respirator malfunctions and breathe in the radiation-laden air, which may or may not have caused the fatal cancer which they developed years later.)
McKinley was already dead, and Byrnes died shortly after being removed from the building. But the third man, Legg, was still unaccounted for. And so some of the volunteers went back into the reactor room to look for him. Here, one of them happened to glance up at the ceiling—and saw Legg’s body hanging down, pinned to the cement by pieces of the reactor core. It looked, they said, like a bundle of rags.
The Atomic Energy Commission instantly realized that the triple fatality could be enough to undermine the entire commercial nuclear enterprise, and it immediately began an investigation. As part of the reactor’s startup procedure, they found, one of the operators had to manually lift the 48-pound central control rod about four inches so it could be connected to a mechanical driver which raised and lowered it into the core to control the nuclear chain reaction. For some reason, though, it looked as if Byrne had lifted the rod some twenty inches--almost all the way out of its channel. Without the control rod, the uranium fuel melted, the nuclear core shot up to over 2000 degrees, the water coolant inside instantly flashed into steam, and the immense pressure tore apart the reactor. The steam explosion blasted Byrnes and McKinley against the cement walls, ejected the reactor head, and blew Legg, who had been doing some work atop the core, all the way up to the roof and impaled him there, while at the same time flooding the room with a lethal dose of radiation. (The bodies were so radioactive that they would be buried in a fenced-off section of the Station’s grounds in lead-lined coffins.) It had all taken less than a second.
But the AEC also found that the workplace at the test facility had become tense and that there was a lot of animosity between Byrne and Legg, with the two of them already having been involved in some altercations, including a fistfight that had to be broken up by a superior officer. There were also rumors that Legg had been having an affair with Byrne’s wife and she had been seeking a divorce, and that Byrne had been a sometime customer in one of the red-light bars in Idaho Falls. Legg himself, meanwhile, had been reprimanded just before Christmas for disciplinary issues and had been threatened with a transfer out of the nuclear program.
In the absence of any direct evidence of what actually happened, then, the AEC’s investigation concluded that the accident had most likely been an odd murder-suicide, with Byrne intentionally, perhaps impulsively, removing the control rod in order to kill both himself and Legg.
There was another equally compelling explanation, though. The entire design used for the SL-1 control rods was inherently risky. There were only nine control rods total in the design, and only five of these were in use during the accident, but nearly all of the work was actually done by the single central rod which, if pulled out too far, allowed the reactor to become uncontrolled. There had already been several incidents before when the SL-1’s cadmium rods had become stuck in their channels due to corrosion. So it was entirely possible that when Byrne tried to lift the central control rod into place, it had become misaligned, and, perhaps in frustration, he had to pull extra hard on it to move it—leading to an accidental withdrawal.
Another possible explanation is that Byrne was “exercising” the control rod---sliding it back and forth in its channel to remove any corrosion and allow it to move freely without sticking. He may then have accidentally pulled the rod out too far.
The whole matter has been the topic of spirited debate ever since, with some investigators concluding that the AEC went with the “murder-suicide” theory because it absolved the reactor design of any blame and protected the reputation of the fledgling nuclear industry. We will never know for sure.
NOTE: As some of you already know, all of my diaries here are draft chapters for a number of books I am working on. So I welcome any corrections you may have, whether it's typos or places that are unclear or factual errors. I think of y'all as my pre-publication editors and proofreaders. ;)