UF's Reactor Returns

This original article was published in April of 2015. See the original article here: http://www.gainesville.com/news/20150413/ufs-nuclear-reactor-back-ready-to-assist-students

 

The small nuclear reactor on the University of Florida campus has been sleeping for about four years while the Nuclear Science Center was renovated.

Just over two weeks ago, it woke up — with upgrades.

And it’s still safe, UF officials said last week.

“The laws of physics actively prevent anything from going wrong,” Nuclear Training Reactor Director Kelly Jordan said.

UF’s reactor can’t make electricity like a normal nuclear power reactor because it runs with 10,000 times less power than a typical power-generating reactor, Jordan said. It also does not have the related machinery necessary to generate electricity.

The UF reactor — on the ground floor of the Nuclear Science center near Weimer Hall and the Reitz Union — is one of 31 reactors in the United States used for student training and research.

“There’s been a slight renaissance of nuclear power needs because of climate change,” said University of California Irvine Nuclear Training Reactor Supervisor George Miller. “So, there are somewhat more students going back into nuclear engineering and nuclear science programs than there were maybe 20 years ago.”

For these students, Miller said, training reactors are a way to apply what they learn in class to real life.

Previously, engineers at UF controlled the UF reactor without any digital instruments. The safety rules, enforced by the Nuclear Regulatory Commission, are strict.

“We have fairly detailed and extensive procedures where you literally do high-level diagnostics in every component of the entire system,” Jordan said.

Now, UF students and researchers will be able to monitor, start and shut down parts of the UF training reactor with the latest gadgets. There are built-in kill switches that stop the reactor if things like radiation levels reach a limit, the temperature gets too hot, or power goes out.

The UF training reactor doesn’t run all the time. When it’s not in use, metal plates called control blades absorb any extra neutrons.

When a researcher wants to test a nuclear experiment, a computer can remove the control blades from the reactor’s heart — the core. The researchers then insert fuel full of neutron-heavy elements into the core that will start a nuclear chain reaction.

Starting this reaction is like making the first shot in a game of pool. A player hits a white pool ball, knocking it into other balls. These other balls keep hitting more balls.

On the pool table, the force of friction slows the balls down until they stop moving. The control blades work similarly to friction, stopping a chain reaction when researchers are done or if things appear to get out of hand.

Along with 500 or so pages of safety analyses, Jordan co-authored a paper in a January 2015 issue of the Nuclear Engineering and Design journal.

He looked at the worst-case scenario: The UF reactor, running for 30 days straight, is hit by a falling concrete block weighing 4,500 pounds. Jordan proved, with a couple of assumptions, that somebody could stay inside the reactor cell for an hour before his exposure to radiation was more than the max allowed.

To the outside world, radiation released from such an incident would mean exposure much less than the yearly safety maximum.

“This reactor’s as safe as they come,” Jordan said.

The reactor makes barely any waste because it runs at 100 kilowatts — about the power of 100 everyday microwaves.

“We have our fuel,” Jordan said, “and that’s our fuel; we never use it up.”

Any spent fuel would be sent to the U.S. Department of Energy in Idaho, he said.

Jordan and his collaborators are now crossing things off a checklist to make sure all the systems are working.

Renovations to the Nuclear Science Center continue, but Jordan plans to start using the reactor for nuclear radiation research within the next two months.

“It should be in much better and safer and newer condition,” Miller said. “We only wish ours could get refurbished.”