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  • When you think of the word nuclear, what comes to mind?

  • It's probably some terrifying thought.

  • I can't blame anyone for being nervous.

  • It's a technology that we've been using for decades that can really reduce global

  • warming,

  • but it's not exactly something environmentalists are that excited about.

  • The first thing many people think of is nuclear war and mushroom clouds.

  • You add into that major events like Three Mile Island and Chernobyl and now most recently

  • Fukushima,

  • and those have had incredibly profound consequences on people's immediate feelings and images

  • and associations with this technology.

  • This isn't something where the public has the view wrong.

  • It is a technology with a reputation that's been earned.

  • I mean, if a nuclear power plant was being built in my town, I'd be pretty nervous

  • about it.

  • However, as a conservationist, that makes me feel really conflicted because these power

  • plants don't emit CO2,

  • and that's the main pollutant that's causing climate change.

  • When you look at the technology and you ask yourself:

  • How are we going to solve this problem of climate change?

  • To not have nuclear energy be on the table makes the job much harder.

  • Now for the most part these plants work really well.

  • They supply about 20 percent of the electricity on the US power grid.

  • But almost all of them in the US were built over 35 years ago.

  • In fact, they look like something out of a vintage movie set.

  • And historically they've had two big problems:

  • They produce radioactive nuclear waste and they can be vulnerable to a disaster like

  • a nuclear meltdown.

  • Nuclear meltdowns happen because water that's used to cool the radioactive fuel rods can't

  • be pumped in.

  • Usually due to something like a backup power failure.

  • This fuel heats up rapidly, and since these reactors operate at high pressure, there can

  • be explosions from all of this excess heat.

  • You can think of it like a balloon popping and releasing the air insidebut in this

  • case, radioactive air.

  • Leslie Dewan is trying to fix this.

  • She runs a startup company called Transatomic Power.

  • They're trying to build new power plants without this problem.

  • Our reactors operate at atmospheric pressure and you don't need that typical containment

  • dome.

  • You don't need the big stacks.

  • You have a lot more flexibility in the architecture of the plant.

  • And that low pressure also means there's no way to have that nuclear balloon pop scenario.

  • But it isn't just about stopping disasters.

  • The fuel itself is toxic and has to be stored underground for thousands of years.

  • And unfortunately we don't use it very efficiently.

  • The solid fuel can only stay in the reactor for a limited amount of time before it starts

  • to break itself down and you have to physically remove it.

  • You can only extract about 4 percent of the energy that you could conceivably get out

  • of the uranium, and the rest is left behind as waste.

  • This is like opening up a bottle of water, taking a sip, and then tossing it out.

  • But that's actually how older reactors use nuclear fuel.

  • The next-generation reactors are using fuel much more efficiently.

  • Transatomic's reactor design will use the fuel in a liquid form so that it can stay

  • in the reactor for a longer period of time.

  • A lot of the advanced nuclear reactors can consume much more of the energy from the uranium.

  • You can get much, much higher fuel utilization.

  • Which means that you're leaving significantly less waste behind.

  • And this is a trend in the field.

  • There's a huge interest to phase out conventional fuel rods for different forms of fuel, for

  • a variety of reasons.

  • In the last 20 or 30 years, we've developed different types of fuel, which cannot melt.

  • And which in fact

  • What do you mean by that?

  • Physically cannot melt.

  • That's Per Peterson, he's a nuclear engineer at the University of California Berkeley who's

  • working on a next-generation reactor design that uses an entirely different form of fuel.

  • Many older plants still use conventional fuel rods.

  • This new design, known as a fuel pebble, encases uranium in a golf-ball sized sphere.

  • It's made of a very strong ceramic material that can withstand much higher temperatures,

  • so it cannot melt and is safer to use.

  • Now this one was built to demonstrate that you can fabricate it.

  • So it does not have uranium in it, but every other way it is identical to the real thing.

  • Same weight and everything like that?

  • And they're designed to be very safe.

  • You can drop this thing from 10 meters onto a steel plate and it won't break.

  • Or if I wanted to I could drop it right now.

  • So essentially, that fuel pebble is designed to be its own self-contained system.

  • If a power failure does happen, the pebbles just empty into a holding tank where they

  • cool down on their own.

  • No need for backup generators or water to keep it cool to prevent a meltdown.

  • Okay, so why hasn't this happened yet?

  • I mean we have better materials, we have reactors with new designs and fuels that makes less

  • waste.

  • It actually sounds like we have the answers to our problems.

  • So what's the catch?

  • You know the old phrase, you never get a second chance to make a first impression?

  • People's first impression of nuclear energy and nuclear power was mushroom clouds.

  • And if it's got the word "nuclear" associated with it, it's just going to be very difficult

  • to convince people, no, no, we mean it this time.

  • This one's safe.

  • It puts nuclear energy in a very challenging place.

  • Right now even solar and wind are cheaper than nuclear power.

  • So there isn't a lot of economic incentive to build these power plants.

  • And if no one wants to build them, then companies that make the parts go out of business or

  • go somewhere else where new plants are being built, like China.

  • Those that are under construction now, the economics have been really grim.

  • The number of plants that have been started and the price overruns have been massive.

  • One of the problems is just simply transporting the components.

  • Instead of getting parts locally like we did in the 1960s and '70s, the parts today are

  • shipped from overseas.

  • And these aren't just basic nuts and boltsthese are huge complicated components.

  • If a section of a reactor vessel breaks during transport, it needs to be fixed or a new one

  • needs to be built and reshipped, taking more time and money to complete.

  • I think that it's going to be very interesting to see how startup companies tackle those

  • problems.

  • And this is a very different space from where the traditional technology evolved.

  • Now rapid innovation has happened in other industries.

  • Look at SpaceX for example.

  • They went from a concept rocket to delivering supplies to the International Space Station

  • in a matter of years.

  • The technologies that are being researched now that look very promising range from small

  • modular reactors where the whole nuclear power plant comes on the back of a flatbed truck,

  • gets parked, plugged in, and when the fuel is used up simply gets taken away as a unit

  • to be reprocessed.

  • These small modular reactors could have specific uses.

  • Like powering a data center that's using electricity around the clock.

  • We have startups building cheaper, smaller reactors that don't melt down.

  • We have engineers making fuel that doesn't produce much waste.

  • While the public image of nuclear energy is rooted in the past, the nuclear energy of

  • today is a whole different ballgame.

  • People like me view nuclear as being a necessary piece of carbon-free energy production.

  • There's less of that fear of nuclear, and more of, sort of a need to use everything

  • in our toolbox to combat climate change.

  • There are other energy sources that we may be overlooking.

  • For example, scientists are actually turning to poop to power cars.

  • Head over to climate.universityofcalifornia.edu for more.

When you think of the word nuclear, what comes to mind?

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