Nuclear cars, with help from thorium lasers

By Andrew Nusca | August 30, 2011, 8:53 AM PDT

Could radioactive elements power future cars?

To be sure, it’s a crazy concept chock full of problems — safety, infrastructure, sustainability, education — but suspend your skepticism for just a moment and consider.

In this week’s Txchnologist (theme: “Advanced Output”), Steven Ashley writes of a thorium laser power generation system that could one day (albeit in the distant future) provide electricity for the grid, power appliances or homes and most compelling of all, power a future car.

The man behind the work: inventor Charles Stevens, whose Massachusetts-based firm Laser Power Systems is working on the development of a turbine/electric generator system powered by “an accelerator-driven thorium-based laser.”

Thorium, a mildly radioactive metal, is abundant, especially in India. It’s considered a good stand-in for uranium in nuclear reactors because its fission is not self-sustaining — meaning it won’t become unmanageable.

By lasing, or exciting, the element, the thorium produces heat, which flashes a fluid to create pressurized steam that drives a turbine that turns an electric generator. It all happens inside a closed-loop system.

Ashley reports:

A 250-kilowatt unit (equivalent to about 335 horsepower) weighing about 500 pounds would be small and light enough to put under the hood of a car, Stevens claims. And because a gram of thorium has the equivalent potential energy content of 7,500 gallons of gasoline, LPS calculates that using just 8 grams of thorium in the unit could power an average car for 5,000 hours, or about 300,000 miles of normal driving.

To to mention that it would be free of emissions.

It sounds far-fetched, but Stevens isn’t alone in this thinking: at the 2009 Chicago Auto Show, General Motors unveiled a thorium-powered concept car under its Cadillac marque. Designed by Lorus Kulesus and named the “World Thorium Fuel Concept,” the concept wasn’t a working prototype but nonetheless was sufficiently provoking for GM to display the concept publicly.

For now, the most imminent hurdle is not concerning the laser proper but the turbine and and generator, which are too large for automotive use.

A laser-powered car? Sounds plenty futuristic to us.

Thorium lasers: The thoroughly plausible idea for nuclear cars [Txchnologist]

Photos: GM