Small nuclear reactors are the mobile homes of the the nuclear power universe — they can be built in factories rather than on-site, then shipped to their destination and hooked up to the local power grid without any expensive upgrades to transmission infrastructure.

The Tennessee Valley Authority power company just signed a letter of intent to buy a half-dozen of them from Babcock & Wilcox, which has experience building them for use on ships. They're a known design — they use pressurized steam, just like every other power plant — so getting permits for them shouldn't be too hard.

That doesn't mean they're a good idea, though. While small nuclear reactors can be built and permitted more quickly than the big kind, no one knows what the ultimate cost of their electricity will be, and some of their costs are identical to conventional nuclear power plants. Even though they're smaller, they require the same amount of security, for example. Also, they are nuclear plants, which some people don’t like at any scale.

"If it were my money, I wouldn't invest in them," Michael Golay, professor of nuclear engineering at MIT, told Technology Review. Maybe what they need is a good marketing campaign and a catchy brand name — “Suitcase Nukes,” perhaps?