How Nuclear Power (Probably) Works

I saw this comment posted on the Freakonomics Blog by user AaronS (a frequent commenter), and I thought it served as a good explanation for how a nuclear power plant operates. Granted, I don't know much about nuclear power, but this sounds right. Here's the explanation (almost) verbatim:

A lot of folks see the world “nuclear” and get a bit concerned. That’s understandable. But some years ago, my cousin, who is an electrical engineer for TVA, took me on a tour and made it very simple. Here it is the elementary explanation (and the best one I understand):

A nuclear plant is really a huge steam engine. It’s sole purpose is to produce steam that will turn a massive turbine (or turbines), and which will, in turn, produce electricity.

To produce the steam, atomic material is submerged in a large tank of water. (This tank, by the way, along with all the pipes connected to it, is completely self-enclosed. This water never runs into the river or the ground, but stays in the pipe.) This atomic material, being active, has a lot of atoms/electrons flying around. They bump into each other at an increasing rate of speed, generating heat. Of course, being submerged in water, this heats up the water, generating steam.

Before I go further, lest someone think it might all get out of hand, to prevent overheating (a meltdown), each nuclear plant has, in the tank of water, “rods” of material that serve as a kind of magnet to these very active atoms. When those rods are lowered, those atoms stop flying around, stopping the heating process. And when it’s time to produce more steam, the rods are lifted as needed.

OK, so all that steam runs along these self-enclosed pipes and turn the turbine, producing electricity. But that water has to then be cooled. What happens is there is a parallel pipe of cold water that runs alongside the pipe filled with the steam. This allows the heat to transfer to the cooler water, thus turning the steam back into water for further use in the nuclear process.

This cool water (now hot), was likely drawn from a river and is not radioactive. But it is still hot. What to do with it? Well, it is pumped up to those huge cooling towers.

Inside the cooling tower, about halfway down, is a “field” of dimpled rectangular plates (about 4 inches by 12 inches, if memory serves). This non-radioactive hot water is sprayed on those dimpled plates, the dimples serving to provide more surface area for cooling purposes. As the water trickles down the plate, it is exposed to the cool air, and cools down. But it does produce the steam/condensation that you may see rising from these cooling towers. As big as they are, you think that is where the real work is being done, but it’s just cooling off water.

I know that won’t cut it with some of you engineers, but that’s the very simple version of how nuclear energy works…and perhaps shows that we should not be so fearful about it as we have sometimes been led to be.

— Posted by AaronS

Loading Image

Click anywhere to cancel

Image is Unavailable