Idaho may be best known for potato production, but 62 years ago a small, experimental nuclear reactor located between Idaho Falls and Arco generated electricity from nuclear energy for the first time.
This milestone occurred on Dec. 20, 1951, paving the way for the development of the commercial nuclear industry. This pioneering reactor operated for 12 years before shutting down to become the Experimental Breeder Reactor No. 1 (EBR -1) Atomic Museum located on U.S. Highway 20-26.
On Dec. 2, 1942, a team of engineers and scientists lead by Enrico Fermi achieved the first controlled nuclear chain reaction. Just two years later, Walter Zinn, at the urging of Fermi, his friend and colleague, began planning the first small-scale “proof-test” of a unique nuclear reactor even by today’s industry standards.
EBR-1 would prove the feasibility of a breeder reactor design using a liquid metal coolant, as well as incorporating a turbine and generator to produce just over one megawatt of electricity. Construction began in 1949 and the building housing the breeder reactor was completed in 1951.
From the start, electricity production was secondary to proving that a nuclear breeder reactor could actually produce more fuel than it consumed. By 1953, a detailed laboratory analysis showed that EBR-1 indeed created more than one new atom of nuclear fuel for each atom consumed.
For an energy hungry world, EBR-1 had achieved the energy “alchemist’s” dream. At that time, only limited quantities of uranium had been discovered. More than 99 percent of the naturally occurring uranium is the stable isotope U238 and the remainder U235, which has an unstable atomic structure that can be induced to split or fission in a nuclear reactor.
Breeder reactors that produced more fuel than consumed seemed the best option for building the foundation for a commercial nuclear industry. This design made sense considering the limited availability of uranium for fuel fabrication.
In pressurized or boiling water nuclear reactor designs, the unstable U235 atoms fission, releasing two or more neutrons that are slowed by a moderator (like water). These free neutrons collide with other U235 atoms creating heat to produce electricity from a steam-driven turbine.
In a breeder reactor such as the EBR-1, free neutrons are allowed to move faster and are absorbed by U238, which then becomes plutonium (PU239). PU239 is a “man-made” element that can also fuel nuclear reactors – allowing breeders to use virtually all of the energy from natural uranium.
As new uranium deposits were discovered and fuel was abundant, the interest in breeder reactors waned. Pressurized water and boiling water reactor designs became the foundation for the nuclear industry’s rapid growth 30 years ago.
Today, several countries operate breeder reactors and research continues in the field of “fast” reactor technology. Perhaps one day, the dream of limitless energy demonstrated in the Idaho desert in 1951 will become reality.