Looking out over the flat expanse south of Arco, its understandable why it has been used for nuclear reactor experimentation and development. Any slip ups would render uninhabitable a plain already devoid of trees or towns. It's pretty empty here still, with most of the 900-square mile Idaho National Engineering Laboratory closed to the public.
A historical marker at a scenic pull-off boasts that "Since 1949, more nuclear reactors -- over 50 of them -- have been built on this plain than anywhere else in the world."
The world's first peacetime use of nuclear power occurred when the U.S. Government switched on Experimental Breeder Reactor #1 (EBR1) near Arco, Idaho, on December 20, 1951. The town of Arco* became the first city in the world to be lit by atomic power from a reactor built near EBR-I, the BORAX III, on July 17, 1955. It was only temporary, but the way was paved for commercial use of nuclear power. The Arco reactor later suffered a partial meltdown -- another World's First. There's no highway sign bragging about that.
At EBR1, tours are self-guided. See "the hot cell," sealed from the rest of the world since 1974, and protected from you by multiple layers of oil-separated glass four feet thick. They made plutonium-239 in this blocky building. You can take pictures, try your skill at operating a robotic arm, and act out your own China Syndrome in the main control room.
Outside, picnic tables are thoughtfully provided under a pair of house-sized atomic jet engines, another experiment. Nowadays the site likes to promote its peacetime mission and environmental charter.
*A yearly highlight in Arco is its annual "Atomic Days" celebration, usually held the second or third weekend in July.
