How to drive forever

What if eight grams of fuel could power your car for a lifetime? What if that fuel was a radioactive element? Would you still be excited? If you’re not, don’t worry. This time it won’t be anything like the ridiculous concepts in old issues of pop-sci magazines.

The dream of a nuclear-powered car reaches back to the mid-twentieth century, when Ford introduced the prototype Nucleon. It was to be powered by traditional uranium fission reactors — the same ones found on submarines and aircraft carriers. The concept was plagued with a multitude of well-founded safety concerns and never came to be.

However, a company in the U.S. wants to resurrect the idea of nuclear traffic. Laser Power Systems said it can bring nuclear powered cars onto the roads within two years. Nuclear powered cars that are safer, more efficient and more importantly, potentially cost effective.

The secret lies in the world’s favourite nuclear energy underdog — thorium. Despite being named after the Norse god of thunder, the element is stable, safe and silent. Some of you reading this may be asking “why aren’t we using it to power everything then!?” . . . before quickly reaching for your notebook, in which you no doubt have an exhaustive list of the reasons that thorium isn’t safe.

You may have read the Guardian’s piece on thorium during a late night reading binge in which you attempted to draft a Nobel-worthy thesis. You’ll exclaim, “Thorium cannot in itself power a reactor; unlike natural uranium, it does not contain enough fissile material to initiate a nuclear chain reaction. As a result it must first be bombarded with neutrons to produce the highly radioactive isotope uranium-233”!

It’s true, the previously attempted thorium breeder reactors were nothing more than uranium reactors that used a much more abundant fuel — and had limited weapons potential. Then there is the issue of dealing with the molten salt — the typical cooling agent in thorium reactors, as opposed to water in uranium plants. Though more stable, salt is corrosive and requires extensive care and special equipment.

It doesn’t really sound like anything you’d want on the roads, right? That is, until you realize the company has no intention of packing a nucleon-esque breeder reactor under the hood of your mom’s minivan. The solution lies in the company’s use of lasers. Who would have guessed with a name like “Laser Power Systems”?

Wardsauto.com explains how it works: “Small blocks of thorium generate heat surges that are configured by a thorium-based laser. [ . . . ] These create steam from water within mini-turbines, generating electricity to drive a car.” The unit weighs around 226 kilograms (a little bit more than a typical car engine) and produces up to 250 megawatts of power.

According to inventor Charles Stevens, one gram of thorium is enough to produce as much energy as 28,390 litres of gasoline. Add to this the fact that thorium has little natural radioactivity and “what isotopes there are could be blocked by aluminum foil, so the power unit’s 7.6 centimetre thick stainless-steel box should do the trick.”

There are still hurdles to overcome, though. The problems don’t concern the radioactive material or even the lasers. Thorium is incredibly difficult to process into weapons-grade nuclear material and laser technology is already compact and efficient. The issue lies with the power turbines, “which have to be made small enough to fit inside a vehicle while generating enough electricity.”

If this problem is solved — and Stevens believes it will be — he’ll have a working prototype by 2014. It could mean a revolution in automotive power. There would be no need for batteries and their hazardous, costly components; the power is created within 30 seconds of activation and is fed continually to the system.
Hopefully, we’ll see these on the roads soon, but until then the idea remains firmly in the realm of “too good to be true.”

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