Idaho Falls

On January 3, 1961, an explosion at the Nuclear Reactor Testing Station in Idaho Falls killed three military operators, two soldiers and one sailor. It was the first meltdown in the US. From the article:

"SL-1 Reactor Incident
SL-1
On January 3, 1961 a steam explosion and meltdown at an NRTS reactor named “SL-1” (short for Stationary Low-Power Reactor Number One) killed three Idaho Falls operators.

It was the first reactor malfunction that resulted in fatalities at any atomic-related site since the AEC’s founding in 1947. Immediate concern that the explosion could result in radioactive contamination of nearby towns was soon alleviated, as health physicians and NRTS management officials measured negligibly low levels of radiation beyond the immediate site of the reactor.

Nonetheless, the informality in which reactor operators had conducted their business would soon come to an end. The SL-1 explosion led to a major structural review of reactor procedures. The site manager, Allan Johnson, resigned and an internal investigation ensued. The AEC mandated stronger definitional responsibilities for site employees and limited operational parameters for contractors. Shutdown procedures and control systems for reactors across the nation came to the immediate attention of the AEC. One site supervisor stated:

“The SL-1 accident was a big watershed point. Up until then, our detailed procedures weren’t much, but we were able to get a lot done in a short amount of time. After SL-1, the reactor was shut down, and we had many, many reviews of procedures. Some reactors at the Site went two years before starting up again. There were committees, and everyone was reviewing procedures and developing formalized sign-offs. It turned into a totally new way of doing business with reactors” (Stacy, 2000).

The reactions of surrounding towns, though, were quite minimal. In the short term, public acceptance of nuclear power went largely unchanged despite the unprecedented nature of this event. An estimated 790 people were eventually exposed to harmful doses of radiation throughout the explosion and subsequent cleanup (Maslin, 1984), but local residents did not seem to muster any considerable alarm that the laboratory posed a threat to their safety.

As criticism of nuclear power become more widespread in the late 1970s and early 1980s, the SL-1 incident came under increased public scrutiny. As public support for nuclear power waned, the incident became one example to which protesters referred in order to argue that nuclear power posed a threat to public safety and that the exploration of its potential uses must be curbed."