The Mystery of SL-1

On the evening of January 3, 1961, nestled in the desert away from the rolling hills and titular waterfalls of Idaho Falls, Idaho, sat Stationary Low-Power Reactor Number One. There have been plenty of fascinating and infamous nuclear accidents over the years throughout the world, but this one might just plague me the most. At this point, you may be asking yourself what this has to do with true crime? Just hold on to your pantaloons and we’ll get there.

To get a feel for how gruesome this accident really was let’s go over the basics first. The SL-1 was an army-run reactor at this time in its history, and the design was such that it had a central control rod that highly affected reactivity in the reactor’s core known simply as “Rod Nine”. It also required that an operator manually adjust Rod Nine by removing it four inches from the core to attach it to an automated control mechanism from which it had been disconnected for maintenance. Or otherwise very simply put, when operating the reactor and especially Rod Nine, one had to be exceptionally careful.

Now, on this particular evening while an operator by the name of John A. Byrnes was removing Rod Nine an excursion occurred. Scientists were able to discern from the state of the rod after the accident that instead of four inches, the operator had withdrawn it twenty inches. The reactor thermal power shot up to 20 GW which was 6,000 times more than its normal operating limit. This had catastrophic results for Byrnes and his two fellow operators Richard Leroy McKinley and Richard C. Legg. The core suffered a complete meltdown and shot steam and debris so violently it killed Byrnes almost instantly and injured McKinley who survived in the wreckage for a few hours before succumbing to injuries. At the time of the excursion, Legg was standing on top of the reactor vessel and was impaled by a shield plug that came off with the other debris. The plug entered through Legg’s groin and exited his shoulder, pinning him to the ceiling and killing him instantly. When first responders appeared on the scene they were expecting a false alarm after dealing with many of them lately. However, upon realizing their radiation detectors spiked drastically as they climbed the stairs it became clear something was amiss.

The horrible fate of the three men could have been so terribly avoidable, and for many people, that is the big mystery about this case. Why did he pull Rod Nine out so far? There are several proposed theories, so let’s get into them.

The simplest theory that investigators settled on was that the rod became stuck in its channel and Byrnes was simply trying to unstick it, had pulled too hard, and killed them all almost instantaneously. However, there were never any reports of this particular rod sticking and all the other reports of sticking rods were during times the reactor was operating, not being started up like this. Not to mention that every operator knew very well the consequences of pulling out Rod Nine too far. This led many to consider the theory that perhaps Byrnes was suicidal and was using the reactor to end his life. Though all witnesses to his last hours of life are also dead, it was reported that Byrnes’ marriage was in trouble and had been made worse by the recent Christmas break. His wife called him at approximately 7:00 pm that day and asked him for a divorce over the phone.

There is yet another theory that adds to this that suggests Byrnes may have wanted to take Legg out with him. There was reported tension between the three men when they began their shift that day as Byrnes was likely dissatisfied with the fact that Legg had come to work at the reactor at the same time as he had years before and this was the first day of Legg having been promoted to be Byrnes’ supervisor. There are also sources reporting that this was not the first source of tension between Legg and Byrnes and that the two had gotten into a fistfight at a party the previous year. There are also rumors that suggest that Legg was sleeping with Byrnes’ wife and that perhaps this was one of the reasons for the divorce Byrnes’ wife had requested, and subsequently the possible murder-suicide.

Among the reactor operators it had also become a common saying among them that “if there was ever a Russian invasion they would just destroy the reactor with the main control rod.” So perhaps there was even some espionage at play. I personally favor the murder-suicide theory, though ultimately there is no way to know for sure with the reports and evidence that exist today. For the time being, we'll just have to continue to theorize, but to me, it remains the most interesting case of possible murder-suicide by nuclear reactor.