Nuclear Science Center director says Narragansett Campus reactor is secure

03/07/08 - It's not a myth that radiation glows in the dark (it's blue). Even fewer people know that the University of Rhode Island can prove it with a nuclear reactor on its Narragansett Bay Campus.

But it's very small, said Terry Tehan, the director of the URI Nuclear Science Center. Tehan said the reactor is about three feet tall and has a two or three foot circumference. "It's about the size of a trash can," he said.

A nuclear reactor is a chamber where a reaction between a control substance and a radioactive material occurs, usually involving plutonium or uranium. The radioactive material generates heat, which boils water. The control rods regulate the amount of heat emitted.

The steam from the heated water creates a lot of pressure and spins a turbine, which generates electricity. Nuclear power is one of the most environmentally friendly sources of energy because it doesn't produce greenhouse gasses, and the fuel can last 40 years without replacement.

The problem with nuclear power is the risk of a "meltdown," when the reactor becomes so hot that the structure melts and releases radiation into the atmosphere. The risk is small, but a meltdown could be catastrophic.

However, the reactor on the Bay Campus is much smaller than a commercial reactor and contains very little radioactive material.

"At the levels we run [the reactor] at, we don't get any radiation at the top of the pool," Tehan said, explaining that the bay campus's reactor is suspended in a 30-foot pool of water, which insulates it.

Tehan said the reactor only produces neutrons, and is used for research purposes. Tehan said the neutrons have been used for studying ozone depletion in the atmosphere and cancer research.

Tehan said to study ozone depletion, researchers take a sample of the atmosphere, which is met and "excited" by neutrons. When the neutron activity dies down, decay of the sample begins and the result is measured.

For biological purposes, Tehan said the neutrons can be used to combat cancer by targeting specific cells in the body, as opposed to chemotherapy treatment, which can destroy good cells.

Producing neutrons doesn't take much nuclear fuel, which means there is less radioactive material, Tehan said. He declined to say exactly how much radioactive material there is in the reactor.

"People wouldn't understand if I told you," he said. "But these reactors don't have to have much material."

Other facts that illustrate the reactor's small size is the temperature of the pool. While commercial reactors can heat water up to 600 degrees Fahrenheit, Tehan said, the bay campus's reactor only heats water to about 125 degrees Fahrenheit.

"That's the temperature of your teapot," Tehan said, adding that a researcher once drank some of the water surrounding the reactor.

"He did that to prove how safe the water is," Tehan said.

Tehan said the pool is also encased in a 10-foot thick concrete wall, which would prevent any radiation from escaping. Tehan said that lead, a traditional barrier to radiation, isn't needed because of how thick the concrete is. He said that four inches of concrete is about equal to two inches of lead.

If radiation was to escape, Tehan said sensors would detect it. He explained that when workers arrive at the reactor in the morning, they turn on fans to ventilate the room because although the radiation levels are low, they are high enough to set off the sensors.

Other security measures are in place, and more have been added since the terrorist attacks of Sept. 11, 2001, such as cameras and security guards.

"I spent over $300,000 on all that stuff," Tehan said. He could not give more specific information about security measures. "That's classified. I could tell you but then I'd have to kill you," he said, laughing.

Tehan said if someone tried to sneak in, he or she would be detected within minutes.

The security measures required for the reactor are excessive, Tehan said. The bay campus and commercial reactors must both comply with the same standards. The U.S. Nuclear Regulatory Commission sets safety standards.

"It's like a one size fits all," Tehan said about the standards. "And you apply these standards to everything from a bicycle to a Ferrari."

The fuel in the reactor is not potent enough to be used for a nuclear weapon, Tehan said. The university made sure of that in 1992, when the reactor upgraded from high-enriched uranium, which can be used in a nuclear weapon, to low-enriched uranium.

Tehan said the upgrading process took two years, mostly because of paperwork and the overhaul the reactor received.

"We changed the pumps and the piping," Tehan said. "It really made the reactor almost new. We got a really good deal out of that."

Tehan said the federal government paid for the upgrade.