One of the glories of nuclear technology is also one of its frustrations: You can design a reactor in a hundred ways. It is like the French cheese dilemma: Because there are some 500 cheeses in France, who is to say which is the best?
In the world of cheese, the decision has been made by those who have most successfully brought their cheeses to market, hence the domination by Brie, Camembert and Roquefort.
So it has been with nuclear reactors.
The man who made the market decisions was the late U.S. Navy Adm. Hyman Rickover, the crusty father of the nuclear navy. An autocratic visionary, Rickover feared that if too many reactor types came on the market, there would be expensive chaos, first in the Navy and then in the civilian nuclear industry. He believed that a standardized reactor concept was needed.
Rickover settled on so-called light water reactors: They are the world-standard for military and civilian nuclear reactors, with only the serious exception of Canada’s heavy water reactors. The fuel in these is unenriched natural uranium, but the moderator and coolant is heavy water — water composed of deuterium, the hydrogen isotope with a mass double that of ordinary hydrogen.
Largely left out of the reactor mix have been gas cooling, sodium, thorium, liquid metal, graphite, pebble bed and other concepts, which were tried and orphaned or never tried at all.
Light water is king. With 400 or so reactors working and almost 80 more on the drawing boards or under construction, its supremacy is inviolate. China alone is building 26 new reactors and plans many more.
Now the Department of Energy is pushing — gently, to be sure — the miniaturization of light water reactors in the form of the small modular reactor (SMR).
On Tuesday, it chose one of four competitors, the Babcock & Wilcox Co., to receive $225 million in matching funds for the design and licensing of the first of these SMRs.
The idea is that these reactors will be built in factories and then transported by rail, truck or barge to the site where they are to be installed in phases. They will use passive cooling, obviating the need for pumps in an emergency; will be buried underground; and will be fueled much less frequently than the 18-24 months their big sisters require.
The DOE says this new generation of reactor should produce under 300-megawatts of electrical power, but the manufacturers are hoping for much smaller units, as small as 45 MWe. A big nuclear power plant is 1,000 MWe and more.
To get an idea of the power of a nuclear plant, the average windmill being deployed today generates just 1 MWe when the wind is blowing.
Therein lies the real appeal of nuclear plants: They create just so much electricity.
DOE’s grant is not the final trip to its piggy bank. The three failed contestants, particularly NuScale Power and Westinghouse, say they are going to hang in for a second round, when another $225 million of matching funds will be coming along. DOE does not want to be accused of picking winners and losers, even if that is what it is doing.
U.S. nuclear industry types hope that the new initiative to push SMRs will reinvigorate the nation’s nuclear supply chain with new technology and more jobs. This chain has so deteriorated that, according to David Blee, executive director of the U.S. Nuclear Infrastructure Council, 30 percent of the components of new large nuclear plants have to be imported.
Industry observers believe that B&W won the award because its consortium of B&W, engineering giant Bechtel and the Tennessee Valley Authority (TVA) was especially powerful. TVA is prepared to build one of the new modular reactor plants on a site on the Clinch River in Tennessee, notably at a time when most utilities are relying on natural gas for new generation.