The power of the sun is (nearly) within grasp

After more than 60 years of work, scientists have made a breakthrough that could potentially change the future of energy.

The Lawrence Livermore National Laboratory and the Department of Energy announced this week that they had successfully achieved energy-producing nuclear fusion that produced more energy than they put into it.

U.S. Energy Secretary Jennifer Granholm called it a huge achievement for science and for clean energy.

Marketplace’s Kimberly Adams spoke with Carolyn Kuranz, an experimental plasma physicist at the University of Michigan’s department of nuclear engineering about how the experiment worked.

The following is an edited transcript of their conversation.

Carolyn Kuranz: We are literally fusing two light atoms together to make a heavier atom. And then there’s a slight difference in the mass between the atoms and that is released in energy. And actually the amount of energy is from Einstein’s famous equation – E=MC^2. So mass contains an absolutely enormous amount of energy that can be released using the fusion process.

Kimberly Adams: And so, whereas the typical nuclear reactions that we all know about are involved in splitting atoms apart – nuclear fission – nuclear fusion pushes them together and makes energy that way?

Kuranz: That’s exactly right.

Adams: So based on what we know, from the Lawrence Livermore National Laboratory, can you explain how scientists achieved this particular breakthrough that actually resulted in a meaningful energy gain?

Kuranz: Yes, so the National Ignition Facility has 192 laser beams for a total of 2 million joules of energy. And those are focused inside a small gold canister or cylinder. And inside that cylinder is a tiny, peppercorn sized amount of fuel and the fuel are isotopes of hydrogen. So essentially, hydrogen with extra neutrons. The laser beams create a strong radiation environment that heats and compresses that fuel, or essentially squeezes it. And if it squeezes it for long enough, and it stays hot enough, eventually the atoms will fuse and release energy.

Adams: Department of Energy scientists and lots of other scientists are really describing this as not just a scientific advancement, but an engineering marvel. Can you talk about the scale of effort it took to pull this off? You’ve got this teeny, tiny canister, but there’s a lot of infrastructure around it.

Kuranz: Yes, absolutely. So just the laser itself, the laser fires in about a few billionths of a second, and there are 192 beams that all have to be synced together and arrive at a extremely precise location all at the same time. But then the targets themselves, so they construct these small peppercorn sized capsules that has a thin layer of diamond, and inside that is actually a hydrogen fuel layer, that’s actually solid ice, so it’s cryogenically frozen. And then inside that is actually a hydrogen or deuterium-tritium gas [filling] as well. The filling that they do is also really amazing. The fill tube is just a few microns in diameter, where human hair is about 100 microns in diameter. So you have a fraction of a hair width that you’re filling with this cryogenically cooled fuel. So the engineering that has gone into this facility in general and these experiments is amazing. The field has been working on this for, you know, six decades. Their accomplishments are truly amazing.

Adams: Why, though? Why is this such an important advancement that so many scientists have been willing to devote their whole careers to it, and obviously, there’s been a lot of money put into this as well.

Kuranz: The pursuit of fusion is, essentially, it’s the Holy Grail of energy production. So fusion uses light elements, so one is deuterium. Deuterium is naturally found in water. One gallon of seawater actually contains enough energy from deuterium as 300 gallons of gasoline. So we have a naturally abundant source of energy, that can create a zero carbon energy source. And a lot of people didn’t think that they would see these results in their lifetime, it wasn’t clear that they would ever achieve this, and that the laser actually wasn’t even a high enough energy. So it’s really, just truly amazing that they were able to do this.

Adams: This isn’t even the fanciest laser on the market these days.

Kuranz: Well, that is true. There’s a lot of investment, especially in Europe and Asia, in lasers, and what they’re able to do and the National Ignition Facility, while exquisite in what it can do, construction started in the 1990s. And it’s really based off of technology from the 1980s. So if it were to be rebuilt today, it would be a completely different facility with completely different technology. So I think that in itself is also very exciting because, you know, what we’re able to do with this type of technology – with the right investments and the right resources – what could be possible is pretty amazing as well.

Adams: What are some of the disadvantages of using fusion reactions as a power source for electricity for our homes?

Kuranz: So probably the number one disadvantage is that we actually can’t use it to power our homes at the moment. This was a scientific achievement, to move from that into something that’s powering our homes is going to take a lot of work, investment from both the federal government but also partnership with private industry as well. There is certainly a lot of work to be done. But we can really begin to envision what that work is now that we have created a fusion ignition in the laboratory for the first time.

Adams: Fusion has been described as this game changer, this Holy Grail for clean energy, because this process does not produce greenhouse gases. But there is still, you know, material being used. And frankly, a lot of people are just going to be scared because the word “nuclear” is in it. How do you get past that?

Kuranz: Yeah, that’s absolutely true. With fusion, there is some a small amount of low level radioactive waste that’s created, but it’s not something that would need to be stored off site. And in fact, one of the byproducts of the reaction is tritium, and that actually is used for the fuel so you can reprocess it to become part of the fuel, but all of the waste would just be can be stored on site as well. So in that respect, it is very different from fission technology. But I do think that nuclear energy, whether it be fission or fusion, really needs to be a part of you know, our zero carbon future.

Related Links: More insight from Kimberly Adams

You can visit the Lawrence Livermore National Laboratory website if you want to get more details about their work and a closer glimpse of the massive test chamber.

And just in case you want more details on fusion and its potential benefits, here’s a FAQ from the International Atomic Energy Agency, a group which also hopes to see the development of fusion power by the second half of this century.

Nuclear fusion through the use of tritium is also an important plot point in the 2004 Sam Raimi movie “Spider-Man 2,” which I won’t spoil … but it did lead to a memorable line from one important character:

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