The Traction of Small Reactors

The New York Times’ Matt Wald provides a nicely reported history and the state-of-play in the small reactor world. Just as the first domestic nuclear reactors were scaled up versions of small reactors, current versions of the tiny titans are scaled down versions of full-scale reactors (actually, some of them are – some are based on new ideas entirely).

“They offer the potential for a new paradigm in how we think about construction of nuclear power plants,” Peter B. Lyons, the Energy Department’s assistant secretary for nuclear energy, said of the so-called small modular reactors, also known as S.M.R.’s. He is supervising a program under which the government will pay up to half of the development cost of two different models. One manufacturer already has a contract to develop a plan for two small reactors in Tennessee.

That manufacturer would be Babcock&Wilcox, teamed with Bechtel and the Tennessee Valley Authority (interesting B&W video on this page).

Wald also provides some interesting details about the B&W mPower reactor, which makes clear that small doesn’t mean pee-wee.

Babcock’s reactor, 13 feet in diameter and 83 feet high, can produce 180 megawatts of power, about 15 percent of the power of a large new reactor, but can run far longer before refueling is required: four years, the manufacturer says, versus one to two years for a standard reactor. When a utility company needs more power, it can order another. Babcock refers to the basic design as a “two-pack,” as if the reactors were twin boxes of laundry soap.

The reactor’s emergency cooling system consists of the natural circulation of air. Conventional reactors require operators to start up pumps and align valves, something that was impossible in the Fukushima accident, when a tsunami wiped out electric power.

There’s a fact sheet about the mPower reactor here. And the Generation mPower site that it comes from is a treasure trove of information.

Some aspects of the article are speculative in nature:

And the regulatory structure is not so great for small reactors. Regulatory commission rules for control-room staff levels, emergency planning zones and security are all predicated on large, aboveground reactors. A small one built mostly underground might logically have smaller requirements, but a potential buyer would be reluctant to build one under the current regulatory regime, experts say.

Wald’s right – these are logical assumptions – but still largely unknown until the NRC finalizes its process for small reactors.

Amusing sentence:

But new approaches to nuclear power have been forecast far more often than they have been realized, and some worry that small modular reactors could fall into that category.

First, because what large industry doesn’t forecast more than it realizes – I want my hover car and now! – and second, small reactors seem to have really moved out of that category. Yes, they’re still at an early stage, but they have gained a good deal of traction and traction can carry a process a long way.

Very interesting and highly readable article. Well worth a look.