AUSTIN (KXAN) — Inside the J.J. Pickle Research Campus in north Austin is one of the most powerful power sources on Earth: a nuclear reactor. It’s a little known fact the city has an active reactor located so close to downtown, even though it has been here for decades.

The reactor on the University of Texas’ campus is one of the most active in the country for this kind of research, and it could teach us a lot about the future of space travel.

Last week, NASA announced three companies had been selected to design and build the next generation of nuclear fission reactors. Once completed, the reactors will be used to colonize the Moon and Mars in the next few decades.

The nuclear reactor at UT's J.J. Pickle Research campus is one of the most active in the country. (Courtesy: University of Texas)
The nuclear reactor at UT’s J.J. Pickle Research campus is one of the most active in the country. (Courtesy: University of Texas)

“Anytime we’re trying to travel in inhospitable environments for which there’s no oxygen, there’s no air, we need to have a power system that doesn’t rely upon oxygen, and nuclear power is one of those,” said Bill Charlton, director of the Nuclear Teaching Laboratory at UT.

He said nuclear reactors can last 20-40 years without maintenance, which is really important for space travel. “They are generally built without any moving parts, because once they’re in space, if they break, it’s gonna be very difficult to fix.”

Charlton said miniaturized nuclear reactors, like the type we will use in deep space travel, are already in use now. Many nuclear submarines are outfitted with these reactors, as well as military bases around the world.

Bill said the type the military uses now and will likely be used in space travel are about the size of a trash can.

Wait?!?! Go back! Austin, Texas has a nuclear reactor

For many, the fact we have a nuclear reactor is pretty shocking. This reactor isn’t even the first one that has operated in the city. Charlton said there was one on UT’s main campus in downtown Austin for decades, but it has since been decommissioned.

The one currently operating is located in UT’s Nuclear Teaching Laboratory and has been in use since the 1990s. “This reactor is purely a research reactor,” Charlton said.

“We do work on medical isotopes, so producing radioactive materials that get used to treat cancer or to diagnose heart problems. These are the kinds of things that we can try to contribute to using this research reactor,” said Derek Haas, an associate professor at the Nuclear Teaching Laboratory.

Haas also does experiments testing minerals exposed to radiation. The military uses this research to detect underground nuclear explosions tests around the world.

The Nuclear Teaching Laboratory develops isotopes used in medical research. (Courtesy: University of Texas)
The Nuclear Teaching Laboratory develops isotopes used in medical research. (Courtesy: University of Texas)

The reactor is several stories high and about 15 feet across. At the bottom, fuel rods filled with radioactive uranium fill the core. The fuel roads are surrounded by more than a foot of concrete, various pipes for inserting research samples into the core, devices for measuring the radiation occurring in the core and water — lots and lots of water. At the very top, a hatch can be opened to access the reactor.

A control room is separated from the core by a gangplank. Inside, researchers, students and professors can manipulate the radiation occurring in the core using control rods. The rods are controlled by magnets, except for one that can be launched into the core with an air pump.

By placing the rods further into the core, the amount of energy being produced is reduced by removing the rods the energy increases.

Is the reactor safe? Should we be worried?

Getting to this chamber involves multiple levels of security. A background check must occur before you’re let into the facility. Visitors must then be outfitted with a radiation monitor, pass though a radiation detector and then be guided past multiple checkpoints.

Despite all this, Charlton said reactors are designed to be inherently safe. “You can stand above our reactor, and there’s no radiation dose above that reactor core while you’re standing there.”

This is something I tested myself while gathering video for this story. With the hatch opened, I looked directly into the reactor just a few stories below me. The radiation monitor I wore around my neck for the two hours I toured the facility read .1 millisievert of radiation as I left. A millisievert or mSV is how experts measure a radiation dose. A CT scan of your belly has a radiation dose of 10 mSv.

The reactor was designed by General Atomics and was purchased by the state to be used by UT. Fuel rods are provided by the Department of Energy. The DoE also recovers spent rods.

Charlton said the reactor also has numerous safety measures in place designed to prevent disasters that have happened in the past. Reactors generate power by heating the water around them, turning that water into steam, which then turns a turbine.

The J.J. Pickle reactor doesn’t get hot enough for this to happen. Charlton said it stays at about room temperature and can even be swam in. It is that safe. A filter in the system removes any minerals from the reactor that could become radioactive, keeping the water exceptionally clean and safe.

Researchers, students and professors are able to operate the reactor from a control room located near the reactor. (Courtesy: University of Texas)
Researchers, students and professors are able to operate the reactor from a control room located near the reactor. (Courtesy: University of Texas)

On top of that, the fuel rods are designed to slow the fission reaction occurring within and around them. They are coated with a special material that slows things down once they get to a certain point.

Nuclear reactors: a quick breakdown of how they work

Nuclear reactors occur thanks to the power of fission. Inside of the reactor, neutrons bounce off of the water and materials around them. These materials could include things like graphite. As they bounce, they slow down and collide with the isotope in the fuel rods inside the reactor. In UT’s reactor, this is Uranium 235.

The water around the reactor glows blue as this occurs. The neutrons, traveling at the speed of light, slowed by the water and emitting blue light.

When the neutrons collide with the uranium, they cause this unstable atom to split. That split releases a lot of energy, about 200 million electron volts per reaction, according to Charlton. It also releases more neutrons.

Those neutrons then bounce around inside the reactor, colliding with more uranium atoms, which then release more neutrons, and so on and so forth. This chain reaction is self sustaining.

Nuclear reactors create very little waste. There are no emissions, like a car, and the only material needed to operate them are new fuel rods. The rods at Austin’s reactor are small, about the size of a rolled up movie poster. The ones used in nuclear power plants, however, are around 20 feet long and weigh several tons.

Once most of the uranium atoms have been split in a fuel rod, it must be replaced. This doesn’t mean it can’t be used again. Old rods can be used to power a reactor, but it takes more of them to do it. Nuclear power plants across the country have safely stored for decades. Charlton said all the waste generated at the nuclear power plant in Houston over several decades could fill a small parking lot.

Older fuel rods can also be recycled, their materials broken down and made into new rods. Some countries already do this, like France and Japan. The amount of waste France has produced over the last few decades could fit in a small room, according to Charlton.

The future of nuclear reactors

Haas said he is currently working on the next generation of nuclear fuel rods, ones made of molten salt fuel. “The ones that we have now are great. We’re just trying to go that next step further to make it safer, more efficient, and more cost effective.”

Charlton said education is important as we start to use more reactors for space travel and if we do so here on Earth.

“The better understanding people have of nuclear power, how nuclear power works, how the waste is produced, how the waste is managed, and even just going to and taking tours of nuclear facilities,” Charlton said. “I think that would help in terms of allowing people to have a better understanding of what the scale of this issue is.”