EBR-I Atomic Museum

Arco, Idaho, where atomic energy once lighted the town (for a very short period)

Like something out of the X-Files, the EBR-I Atomic Museum sits in the middle of a vast desert wasteland.

These gates were designed to keep secrets in and people out. They wouldn’t be hard to get through now.

We took this a tour of the EBR-1 Museum on September 5, 2015, while visiting the area around Craters of the Moon National Monument in Idaho.  For me putting this journal page together has been a bit like a school assignment I didn’t understand. The benefit is that in reading the brochure that went with the tour again and matching it to the photos I understand a little better what the facility did and how it worked.  I’m going to copy the brochure almost word for word and put the photos under each paragraph.

1.  The universe is composed of tiny particles called atoms. Atoms of uranium-235 were used at EBR-1 to generate electricity.  A uranium-235 atom splits or fissions when struck  by a neutron.  The splitting atom produces heat and waste products, and releases two or three neutrons  If those neutrons strike other uranium-235 atoms, they will also split, yielding heat and still more neutrons in a chaim reaction.

At EBR-1 such a chain reaction was harnessed to generate electricity and also to demonstrate that more new fuel could be created than the reactor “burned.”  Creating nuclear fuel is possible because of a property of natural uranium.  Less than 1 percent of natural uranium is the fissionable uranium-235.  The rest is another kid of uranium called uranium-238, which does not readily split.  Instead, a neutron is absorbed by a uranium-238 atom, which then changes into plutonium-239, a fissionable atom and a good reactor fuel.  Thus, EBR-1 was a breeder because it “bred” more plutonium-239 atoms than the uranium atoms it consumed.


2.  Compared to other power plants, EBR-1 was unusual mainly in the kind of fuel it used. Coal or oil-fired power plants burn their fuel to heat water to make steam.  This steam drives a turbine that generates electricity.  At EBR-1, the nuclear fuel created heat by means of a fission chain reaction.  The heat was carried from the reactor core by liquid metal, which in turn heated a second system of liquid metal.  This liquid metal was a combination of sodium (Na) and potassium (K) called “NaK”).  The second system containing NaK then heated water to make steam to drive the turbine/generator.


3.  Like all power plants, EBR-1 had a control room. From this room, operators started and stopped the chain reaction and controlled the equipment for making electricity.



4.  In this room above the reactor – a nuclear heat source or furnace.  When the reactor operated the thick concrete walls surrounding it shielded workers from radiation.  The uranium fuel was placed in long, thin, stainless steel rods like these.


The fuel rods were lowered into the reactor core through this hole.


Fission took place in the core, producing heat and breeding more fuel.  There is no fuel in the reactor now.  Notice the exhibit entitled “Breeding Blanket” located in the basement – directly beneath the reactor core – this reflector cup served as the reactor’s “on-off” control.  When the cup was raised to surround the core, the reactor heated up.  The reactor shut down when the cup was lowered away from the core.  Neutrons could escape easily from the small, basketball-side core and be absorbed by the surrounding shielding.


The uranium-238 reflector around the core absorbed some of the neutrons to make new fuel and bounced enough other neutrons back into the core to maintain the fission chain reaction.  Raising or lowering the reflector cup, by means of an elevator, controlled the rate of the reaction.

5.  Steam created by the reactor’s heat rotated this turbine.


The turbine turned the generator to make electricity.  The first electricity generated at EBR-1 illuminated four light bulbs. (In 1951)  On that historic day, EBR-1 staff members chalked their names on the wall to commemorate their achievement.


However, the women working on the project were not allowed to sign their names (even through a male janitor was).  Later to correct this slight a placard was put up with the women’s names on it.


6.  In this room, the heat from the second liquid metal system converted water into high-temperature steam.  The steam was then piped to the turbine/generator where it produced electricity as seen in stop #5.


7.  The nuclear fuel was inside stainless steel rods (actually only in the lower section of the rods).  Extra fuel rods were stored as you see them in this vault. IMG_4251

Before they were used in the reactor, the rods were not very radioactive and could be handled safely without shielding.  After the fission process occurs in the reactor, the rods become highly radioactive.  This is a large cask, which, when lifted by the crane overhead, safely moved the highly radioactive spent fuel rods from place to place.



8.  Some radioactive liquid metal remained on the fuel rods when they were removed from the reactor core.  Liquid metal was washed off in the hole covered by the bright metal place in the floor. (I don’t have photo of this).  Rods were then stored in the individually numbered holes, known collectively as the rod farm.  A chalkboard was used to keep track of the spent rod inventory.


9.  This is the hot cell, used for inspection and repair of radioactive materials.  The window’s 34-layers (total thickness of 39 inches) and 39 inch-thick walls provided radiation protection.

By using our flashlights on our cell phones we were able to light up the interior of the window. This shows the 34 layers of protection.

The manipulators are the first ever devised for remote handling of radioactive materials.  Mechanical “hands” inside the hot cell duplicated every motion applied to the controls by an operator who stood outside the cell, where protection from penetrating radiation was provided by the thick concrete walls and the specially designed windows.

The manipulators are in this window, but are difficult to see due to the reflection and the many layers of glass.

10.  Neutrons could escape easily from the small, basketball-sized core.  But the uranium-238 reflector around the core absorbed some of the neutrons to make new fuel and bounced enough other neutrons back into the core to maintain the fission chain reaction. Raising or lowering the cup-shaped reflector, by means of the elevator you can see through a window, controlled the rate of the reaction.  (No photo of this window, although it looks like the above one.)

I’ve probably missed things and/or made mistakes in this virtual tour, but I’ve tried to give a pretty good overview of the EBR-1Museum.  It was an attempt in the 1950’s to show that nuclear energy could be used for peaceful purposes.  The electricity generated at this plant eventually  powered the plant, as shown by this sign which was displayed in the plant during its functioning days.  The plant actually generated electricity for the little town of Arco for an extremely short time (less than a day) to prove it could be accomplished.


Outside the building these two gigantic engines were nuclear powered jet engines, prototypes to prove this type of energy could be used for different purposes, although they were never put in an airplane.  They were not always outside, but were put here for viewing before entering or when leaving the museum.



 Its apparent when observing the scenery around the nuclear power plant why this location was chosen for work with nuclear energy.



The road employees took in the 1950’s back to their homes and families.  Plans were originally made for housing near the plant for employees, but there was no demand.  People wanted to go back to civilization after work each day.