White House Chronicle Nuclear Reactors and French Cheese Have something in Common By Llewellyn King Published November 21, 2012 – 9:13 am Click here for link to source. 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 are 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 Adm. Hyman G. 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 has been gas cooling, sodium, thorium, liquid metal, graphite 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 on the drawing boards or under construction, its supremacy is inviolate. China alone is building 36 and plans many more. Now the Department of Energy is pushing – gently, to be sure — the miniaturization of light water reactors: the small modular reactor (SMR). On Tuesday, it chose one of four competitors, the Babcock & Wilcox Company (B&W) 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.