Re: Could the ITER fusion reactor explode?

Hi Tommie (and your mum),

It is possible that your question is the greatest question that I have ever been asked on this website. You, your mum, and I are all watching history, technology, and civilization interact. In a hundred years, technology journals will be talking about the decisions and innovations that are being made right NOW, and with the benefit of perfect hindsight, they will say that we were being visionary, or being idiots. The short answer to your first question is that Fusion reactors are at an extremely low risk of exploding. It's practically impossible. The answer to your second question is that no explosion that humankind could currently produce would be able to shift the Earth's axis.

The long answer is quite long.

Some background to get the rest of the class caught up. The International Thermonuclear Experimental Reactor (ITER) is a project on which they have been working since 1985. The world powers (China, Europe, Japan, Republic of Korea, Russian Federation, and the United States) have been collaborating to decide how and where to build this, picking between Spain, France, Canada, and Japan. Right now, the European Union has said that they will go ahead and try it alone and are planning on building the ITER in France.

It's going to cost around $10 billion, be up and running by 2014, and they're not sure if it will work.

Wha????

Yes, they don't know if it will work. We (the human race) have never made a successful fusion reaction last more than two seconds, and even when we did, we used six times more energy to get the reaction to occur than we were able to harness from it. The fusion reaction (which is indeed just like the reaction that occurs in the sun to create light and heat, and is the source of energy for almost all of the life on this planet) is when you take two nuclei of hydrogen, smoosh them together to form helium, and harness the energy that is released from the reaction. The byproducts are radiation, energy (in the form of heat), and helium, an inert gas. So what's the snag? We need these to be at about a million degrees. I'm not making that up. It honestly has to be hotter than 1,000,000 degrees. I haven't found if that's Celsius, Farenheit, or Kelvin, but it's a million degrees, so I don't really care. That's so hot that a 4th state of matter (besides solid, liquid, and gas) exists. It's called plasma, and they're going to use 45 foot high superconducting magnets (which by the way, need to be at liquid helium temperatures (around -250 degrees Celsius)) to keep it contained in the shape of a donut (also known as a tokamak).

The good news:
1) We will eventually get it to work. Most of the previous experiments have failed for the same reason: They were too small. Fusion reactions have to be big to work. Researchers didn't have the funds or ability to construct the kind of equipment that was needed. The fact that national goverments have the foresight to fund a power plant that is basically a research project is exciting.
2) When we get it to work, it will be the cleanest, most reliable form of energy that we have ever used. The emissions and nuclear waste from Fusion plants are "better" (less damaging to humans and the environment, lasts for shorter amounts of time, and is in smaller amounts) than fossil fuels or nuclear energy. Plants could eventually be more productive and more reliable than solar, wind, or hydroelectric power.
3) While you could theoretically use the products and processes of the fusion plant to process nuclear material for nuclear bombs, or worse yet, turn nuclear bombs (A-bombs) into nuclear superbombs (H-bombs), it is NOT going to happen, and I'll tell you why. I could theoretically hammer nails in with a Ferrari. I'd have someone hold the nail, I'd get in the car, and crash into the nail. But I'd have to get access to someone's Ferrari, I'd have to damage it, and I'd have to do it over and over again until my house was built. Or I could use a hammer. There are a zillion ways for people to make radioactive stuff, and almost every one of them is easier and cheaper. As far as using Tritium and Deuterium (the fuel that Fusion plants will use) to turn nukes into super-nukes, that IS how supernukes work. But you can almost build a heavy water reactor in your basement, so building the ITER isn't going to lead to more bombs. And you still need to be able to build a nuke for the supernuke to work in the first place. Without it, you've just got water.
4) Safety. This is the main point of your question. These reactors won't explode. The nature of a fusion reaction is that if we lost containment, or turned everything off, or even if we intentionally overloaded the system and tried to sunburn everything, there wouldn't be an explosion. It's just going to turn off. The possibility of an explosion is so infinitesimally slim, we don't even consider it to be a possibility.
(Side note: An explosion big enough to shift the earth's axis or orbit is theoretically possible, but only from an asteroid impact bigger than any impact that has ever occurred in the geological history of the planet. We have no record of any impact that large. For example, the big honking asteroid that killed off the dinosaurs as well as about 90% of the lifeforms on this planet wasn't big enough to alter the axis. That said, the axis of rotation is changing by itself by about a degree or so every few million years, and the magnetic field reverses itself about the same time as well.)

Bad News:
1) The bottom line is that they are developing a new technology that has never been tested, that is far from being perfected, and in all likelyhood, won't work the first time. Or the second, and maybe not the third. However, this just means that Fusion will be just like every other technology that has ever been invented by the human race. The cool thing is that we'll keep trying, and we'll eventually get it right.
2) The unknown. It is in our nature to feel secure in what we are familiar with, and what we understand. I'm excited about ITER, but I'm also aware of what irresponsible scientists and irresponsible science has done in the past. We have just begun understanding the human genome and all of the benefits that come with that, but I don't like how some scientists are trying to misuse genetic manipulation. We began to understand the atom in this century, but when they first tested an atomic bomb, there were some scientists who genuinely feared that the bomb may ignite the atmosphere and destroy the world. It didn't, but we now have weapons that can and I don't like them one bit. However, there's a difference between fear and a healthy level of respect.
3) Public opinion influences goverment policy, which is what is driving the ITER project. If enough people are against this project, it won't get off the ground.

Please absorb everything that you read, but don't take ANYTHING (not even this article) as absolute fact. Weigh the facts, and make up your own mind. This goes for every issue, not just fusion. Stem cell research, cloning, nuclear power, environmental issues: every issue has two sides, and each side will try to make their point the best they can, even to the point of bias. I hope this helps!

Jeff Yap
Mad Scientist

References:
ITER Home page
BBC News - 11/26/04 - EU decision regarding Cadarache
Stop ITER (Canada) Home page