By Rick Stouffer
TRIBUNE-REVIEW
Tuesday, July 24, 2007

Westinghouse Electric Co. said Monday it acquired for an undisclosed price a South African company known for its work developing an alternative nuclear power technology that proponents say is extremely safe.

Once Westinghouse's purchase of IST Nuclear is approved by the South Africa Competition Commission, which is expected next month, the company will become Westinghouse Electric South Africa (Pty) Ltd. All 118 IST Nuclear employees will be retained.

"ISTN is a key participant in the development of the Pebble Bed Modular Reactor, and this acquisition will allow us to become even more involved as (the technology) moves toward commercialization," Nick Liparulo, Westinghouse's vice president of engineering services, said in a statement.

Westinghouse is a 15 percent equity partner in a proposed 165-megawatt pebble bed facility to be built in South Africa. Pebble bed plants are built in 165-megawatt reactor sections, about one-fifth the size of FirstEnergy Corp.'s 821-megawatt Beaver Valley 1 unit in Shippingport, Beaver County. The modular layout allows the plant to grow in incrementally.

"Pebble bed plants are smaller than our own AP 1000 plant design (165 megawatt vs. 1,100 megawatts), so this gives us expertise at both ends of the spectrum, plus at a time when nuclear power experts are at a premium, this gives us access to 100-plus highly skilled, highly experienced workers," Westinghouse spokesman Vaughn Gilbert said.

"I think this is a very forward-looking step for Westinghouse, it shows it's definitely looking to be a player in the future," said Jay Apt, executive director of Carnegie Mellon University's Electricity Industry Center.

Apt said the pebble bed technology has the potential to deal with one of the great problems associated with nuclear power: proliferation.

Liparulo said Westinghouse intends to expand IST Nuclear's scope to include working on existing light water nuclear reactors worldwide. "We see this as a growth business," Liparulo said.

A pebble bed reactor uses nuclear fuel encased in graphite "spheres" about the size of a billiard or tennis ball. Within the "pebbles" are 15,000 uranium particles, or kernels. During normal operation, the pebble bed contains about 456,000 pebbles.

Pebble bed technology is considered by its proponents to be extremely safe because of passive safety features that require no human intervention and that can't be bypassed.

The reactor is cooled with helium -- not water -- and the gas is used for energy transfer. Helium enters the top of the reactor at a temperature of 932 degrees Fahrenheit, moves between pebbles heated by nuclear fission, and leaves the bottom of the reactor vessel at a temperature of about 1,652 degrees Fahrenheit.

The hot gas enters a turbine that's connected to a generator. The coolant leaves the turbine and is cooled, recompressed, reheated and returned to the reactor core.

According to proponents, a feared meltdown of the nuclear reactor can't happen with a pebble bed system. There's no chance of overheating caused by radioactive decay because of the resistance to high temperatures of the billions of fuel particles within the graphite balls.

In addition, helium is chemically inert, meaning it doesn't react with other elements, and it's also noncombustible. No air can enter the core and corrode the reactor's graphite.

Rick Stouffer can be reached at rstouffer@tribweb.com or 412-320-7853.