Yet more on small nuclear

I mentioned small nuclear power generators once already today, but I didn't realise that a good, fairly recent article had just appeared at Discover too.

There are several companies vying to get the lead in these new-ish breed of reactors. Toshiba's is small but has a long, long life:

Toshiba’s 10-megawatt reactor design promises to be a marvel of low maintenance. It is intended to be sealed and run for up to 30 years without refueling, relying on uranium enriched to nearly 20 percent uranium-235. (Typical reactors use a mix that is only about 5 percent energy-rich uranium-235; the rest is more common uranium-238.) Hyperion’s 25-megawatt prototype, which is based on technology developed at nearby Los Alamos National Laboratory and is similar to reactors long used on Russian submarines, gets by with more conventional levels of uranium enrichment but could still run 8 to 10 years without refueling.

There's another company working on a high pressure water cooled one, but the Toshiba and Hyperion designs use molten sodium and lead bismuth (respectively.) The article says:

Without the risk of water boiling, the reactors can run at higher temperatures, producing enough heat to extract hydrogen from water for use in fuel cells. And if one of these reactors melted open, there would be no venting, just a well-contained hot mess underground.

Well, I'm not sure residents nearby will feel so comfortable about such a leak.

This is the thing that does give me reservations: the articles about these usually say that mini nukes are intended to be buried. But surely that is an issue for an country or region that is earthquake prone. I'm not entirely sure why burying is seen as the attractive option (I think it is meant to provide terrorist resistance, but I am not sure if there are other operational reasons for it.) I suspect most people would prefer to keep the things above ground, even if it means paying for a well armed security force.

All very interesting anyway.