Backers, foes exchange dueling talking points

March 15, 2011

By Tom Fowler
Houston Chronicle

Japan’s ongoing nuclear power disaster may be giving the industry a Chernobyl-sized black eye, but to those in the business not all power plant projects are the same.

Advocates for the South Texas Project nuclear plant about 90 miles southwest of Houston near Bay City point to differences between it and the troubled units at Tokyo Electric Power Co.’s Fukushima Daiichi plant.

The first is location. Fukushima is on the coast in one of the most active seismic zones in the world, while STP is about 11 miles inland from Matagorda Bay in a seismic zone rated 0 — signifying the lowest earthquake probability.

Fukushima’s coastal location probably contributed to the catastrophe there. Officials reported that diesel generators responsible for providing backup power to cooling pumps were swamped by tsunamis that followed last Friday’s massive earthquake.

Fukushima’s coastal location probably contributed to the catastrophe there. Officials reported that diesel generators responsible for providing backup power to cooling pumps were swamped by tsunamis that followed last Friday’s massive earthquake.

3 redundant systems

The South Texas Project is about 29 feet above sea level, spokesman Buddy Eller said, and appears capable of withstanding extreme storm events that are most likely for the region.

A study looking at the possible impacts of a combined Category 5 hurricane storm surge and a 100-year flood on the Colorado River that runs adjacent to the plant site found water levels would rise to just under 28 feet.

The plant also has three separate, redundant diesel back-up systems to run all of its onsite systems, including the reactor cooling. They’re located in steel-reinforced concrete buildings designed to withstand hurricanes and storm surges, said Eller.

There’s also an age difference. The Fukushima units are 30 to 40 years old. South Texas Project Unit 1 went online in 1988 and Unit 2 in 1989, making them the sixth- and fourth-youngest units in the U.S.

The Japanese and Texas plants also use different reactor designs.

In Fukushima’s Advanced Boiling Water Reactors (ABWR), water runs through the nuclear reactor and boils into steam that turns power generation turbines.
In STP’s Pressurized Water Reactor, reactor water is heated under pressure but does not boil, and moves in a closed loop. The hot water in the loop boils water in a separate vessel into steam that runs the electric turbines.

In both designs, steam flows from the turbines to a condenser that cools it into a liquid to repeat cycle.

‘Lessons … the hard way’

South Texas Project operators want to add two new reactors, using an updated version of the ABWR design. Eller noted they would include the same triple-redundant power backup systems and have the same location advantages.

But opponents object to the expansion of the South Texas Project, and asked regulators in a filing this week not to extend the licenses for its existing units.

"We are learning the lessons of nuclear disaster the hard way right now, as the world watches in horror the meltdown of nuclear reactors in Japan," said Karen Hadden, executive director of the Sustainable Energy and Economic Development Coalition.

SEED contends the license extension fails to address adequately the plants’ ability to deal with serious fires and explosions, and fails to justify the extension in light of increased efficiency options.

Also raising concern in some quarters is the involvement in the proposed South Texas expansion of Tokyo Electric – operator of the Fukushima plants.

tom.fowler(at)chron.com