The Next Nuclear Reactor May Arrive Hauled by a TruckTHE first commercial nuclear plant in the United States, commissioned in 1957, was just a scaled-up version of the reactors that powered submarines, and for decades afterward engineers made them bigger and bigger to maximize economies of scale.
But the hot idea now is to think small — small enough to fit a reactor on a railroad car or even a heavy-haul truck.
Such a reactor could be built in a factory, sidestepping the problems of assuring high-quality fabrication in the field and allowing fast installation. And such reactors would have a built-in safety feature: in an emergency, natural convection could help a small core cool faster than a big one, just the way a cup of coffee cools faster than a pot of coffee. Proponents say that makes meltdowns far less likely.
“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.
Because the plants could be safer as well as faster and easier to install, they do not have to surpass big reactors in cost per kilowatt-hour, Mr. Lyons said in an interview. “If it is even equal, it is a winner,” he said. “If it’s better, it’s more than a winner.”
Rebecca Smith-Kevern, the Energy Department’s director for light water reactor deployment, estimated their cost at $800 million to $2 billion a unit, compared with $10 billion to $12 billion for a large reactor. “Basically they’re not a bet-the-farm proposition for a utility,” she said.
Small modular reactors could serve as “starter reactors” for countries that have no nuclear power now, no budget for a standard behemoth-size model and grids too weak to tolerate one anyway, proponents say. (Put a standard, 1,200-megawatt reactor on a small grid, and it could trigger a nationwide blackout every time it shut down unexpectedly.)
In addition to being small enough to ship, the reactors are small enough to be installed underground, offering the advantage of earthquake protection; buried structures are less vulnerable than those above the surface. They may also be easier to defend from attack.
And the ability to air-cool the reactors further distinguishes them from big nuclear plants, which, like coal and most natural gas plants that make steam to drive a turbine, require copious amounts of water to condense the steam back to water. S.M.R.’s make steam, like other reactors, but can condense it back to water using something a bit like a car radiator.
more at link belowhttp://www.nytimes.com/2013/04/25/business/energy-environment/the-next-nuclear-reactor-may-arrive-hauled-by-a-truck.html?pagewanted=all&_r=1&
