Wednesday, June 8, 2011

Arco and EBR-1

Tuesday, 7 June

We drove into Arco yesterday for a few groceries, and again this morning on the way to EBR-1 (more about that later). One of the most memorable things about Arco is the numbers painted on the mountain overlooking town.

These are done by the seniors of every Arco High School graduating class for almost 100 years. The oldest one we could see was 23, but we might have missed some.

This rock building is City Hall, I think. I took this photo because it leads into our next stop, EBR-I.

We drove southeast out of Arco about 18 miles, passing this really cool volcanic cone which was creating its own clouds.

We took the turnoff and drove up to EBR-I.

EBR-I, or Experimental Breeder Reactor-I, was the first power plant to produce usable electricity using atomic energy. It did so on December 20, 1951.

It has been decommissioned since 1964, but was dedicated as a Registered National Landmark in 1966. Is is open to the public for free guided or self-guided tours.

When you enter the building, you first see this mockup of a 1950s living room, with the television showing a short film about the reactor. We were greeted by a young woman who explained that she could be a tour guide or we could use the brochure and take the self-guided tour. We chose the latter.

The first lesson I learned on this tour was about nuclear fission. Short explanation (from the brochure): The universe is composed of tiny particles called atoms. Atoms of uranium-235 were used at EBR-I 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 in turn split, yielding heat and still more neutrons in a chain reaction."

Note: while this sort of makes sense, I have no idea what is done to make the neutrons go and strike the uranium-235 atoms, or where this chain reaction takes place. I just can't seem to wrap my brain around this part of the process and what a reactor core looks like.

What I did understand what how the electricity was generated-the heat was carried from the reactor core by liquid metal, which in turn heated a second system of liquid metal, which heated water to make steam to drive the turbine and generator.

I also understood why this place was a "breeder." again, from the brochure: "At EBR-I, 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 the property of natural uranium. Less than 1 per cent of natural uranium is the fissionable uranium-235. The rest is another kind 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-I was a 'breeder' because it 'bred' more plutonium-239 atoms than the uranium atoms it consumed.

This is the control room, from which scientists started and stopped the chain reaction and controlled the equipment for making electricity.

Some interesting milestones in the history of EBR-I.

There was lots of information about the reactor core, the fuel rods, and the whole process, but like I said, I just can't seem to get it. I saw what the fuel rods look like, and saw where they're lowered into the core, but just don't understand the rest of it. It's still fascinating, though!

In the last large upstairs room was a turbine and a generator, along with a string of 4 light bulbs. In 1951, the initial reaction created enough electricity to light up the light bulbs. It was a momentous occasion, and the men who were all involved chalked their names on the concrete wall to commemorate it. There's now a protective glass covering over those names.

I have to admit that the biggest reason for my lack of understanding is the absence of physical science classes in my education. I never took chemistry or physics, so my mind just doesn't go there. I did, however, take enough geology coursed in college to qualify it as a minor, so you'll understand when I say I have a passion for all things related to geology. That's why I'm having so much fun here at Craters of the Moon.

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1 comment:

Sue Malone said...

I mapped soils in Idaho, and yes, the geology of that world is completely fascinating! Loved the numbers above Arco