The Night the Desert Shook: The gruesome history and legacy of the SL-1 Meltdown

IDAHO FALLS, Idaho (KIFI) — Since the 1950s, the Idaho National Lab, known locally as “the site,” has been the testing grounds for nuclear reactors for both the Department of Energy and the U.S. Military. But producing any type of energy is not without risk of accidents, and the site has seen three.

The first was a deliberate destructive test at the Borax-1 reactor in 1954. The second was in 1955 at the now famous EBR-1 known for generating the first usable electricity from atomic energy. Neither of those accidents injured anyone, and there was no threat of radioactive contamination.

But the third accident, in January of 1961, was much worse. That accident was deadly.

65 years ago, on a cold January night in the west desert, three men were tasked with starting up the “stationary low power reactor number one” or SL-1 after it had been shut down for the Christmas and New Year holidays. What happened that night led to a gruesome chapter in nuclear energy history. 

The U.S. Army had dozens of manned radar stations at the Arctic Circle and this new form of electricity generation seemed like the ideal way to power those outposts.

"That particular reactor was designed - put on your Cold War hat again - for what is called the distant early warning line, (or) the dew line," explains Shelly Norman. "They (the federal government) were going to have reactors and these little outposts along northern Canada and they would use these reactors to power those outposts."

The SL-1 was the testing ground for a reactor that would power a warning system in case the soviets attacked.

On that night in January, army specialists Richard McKinley and John Byrnes, and navy electrician first class Richard Legg were the only men on duty responsible for restarting the reactor. This entailed pulling a single control rod upward between 3 and 4 inches from the bottom of the reactor, but no farther.

"They had just come back, first night from the break," explains Norman as she paints the scene leading to the accident. "It's 17 below zero. The night crew was attaching that control rod to a mechanical arm...instead of pulling it four inches, they pulled it out 20."

At the point where John Byrnes pulled the central control rod beyond 4 inches, a power surge ten million percent above normal operation vaporized the core of SL-1 sending the 26-thousand-pound reactor core over nine feet into the air and firing the control rods, like missiles, into the ceiling.  Sl-1 had just gone prompt critical.

Experiments would show that the explosion was equal to more than 70 pounds of TNT, and all of that energy was sent directly into the bodies of McKinley, Legg, and Byrnes. There were no survivors.

What followed was a lengthy and tedious process of recovering the dead soldiers whose bodies were now highly radioactive and then deconstructing and cleaning up the site. It took a year to complete.

In May of 1961, a burial ground was constructed 16 hundred feet from the original site, where 99 thousand cubic feet of material would be sealed underground. 

The only monument to the reactor, a fence with hazard warning signs encircling the area. Another monument memorializing the three men killed that night sits at the EBR-1 reactor museum overlooking the area where SL-1 once stood.

Lessons were learned from the SL-1 meltdown. No future reactor would ever be built using a single control rod to start operation, but one thing was never determined: Why? Why did John Byrnes pull the central control rod out so far?

The best explanation based on mock-ups and experiments to reproduce that moment is that the control rod was stuck, as it had been many times before, and Brynes simply pulled too hard to get it loose.

But you’d be hard-pressed to find a telling of this story that didn’t suggest it was a suicide or even murder. Earlier that evening, John Byrne's wife had called to tell him she wanted a divorce, and there were rumors that Richard Legg may have been having an affair with her.  

No evidence of foul play was ever found, and the final report that took over 2 years to complete concluded the cause was accidental.

While the failure of SL-1 will always be the focus of that project, SL-1's successes and failures continue to help shape the path of nuclear energy production today.

There have been conflicting reports on where the three men are buried.

However, credible reports indicate that the three men were placed in lead-lined coffins specially made at the site and sent to their families. John Byrnes was buried in New York, and Richard Legg was laid to rest in Michigan. Meanwhile, the body of Richard McKinley is buried in Arlington National Cemetery, Virginia, in a specially constructed, deep, concrete-lined vault. His headstone has an inscription on the back of it that says "Do not exhume: Contact the Department of Energy."