BIG CORRECTION: See below.

General Electric and Hitachi passed one of the key milestones on the long road to deploying a new type of what will arguably be a cheaper and safer nuclear reactor on Wednesday: the submitted for design approval with the Nuclear Regulatory Commission. If they can get design approval secured (the process takes years), a utility that wants to build a plant based on the reactor can then seek approval for a site and, potentially, start to build a nuclear plant with the reactor.

The Economic Simplified Boiling Water Reactor (ESBWR) effectively exploits passive cooling techniques more than older reactors, which means 25 percent fewer pumps and values. Fewer valves means more rapid construction – an entire power plant can be built in 42 months – and at the same time reduces the potential for something to go wrong.

Nuclear appears poised to make a comeback in the U.S. No commercial nuclear plants have been built in the U.S. since the '70s. However, the 104 existing commercial reactor provide 21 percent of the electrical power in the states. Nuclear plants do not emit carbon emissions when operating, but there is that waste problem. Nuclear has also risen in public opinion polls.

A whole host of companies, meanwhile, are developing small modular reactors, fusion reactors and even ones that burn spent nuclear waste (see our guide to new nuclear here). NuScale Power and other new companies are exploiting passive cooling too.

Still, the high costs of reactors, the potential for community opposition, and the long history of delays and cost overruns make both banks and utilities skittish about committing to new nuclear plants.

Correction: I stated in the first version of this that GE and Hitachi got approval. Read the release too fast and got excited. I deeply regret the error.