The Making of the Atomic Bomb: 25th Anniversary Edition

by Richard Rhodes

delivered the first ton of pure uranium oxide processed from Joachimsthal ores to the War Office in January 1940. German uranium research was thriving. Acquiring a suitable moderator looked more difficult. The German scientists favored heavy water, but Germany had no extraction plant of its own. Harteck calculated at the beginning of the year that a coal-fired installation would require 100,000 tons of coal for each ton of heavy water produced, an impossibility in wartime. The only source of heavy water in quantity in the world was an electrochemical plant built into a sheer 1,500-foot granite bluff beside a powerful waterfall at Vemork, near Rjukan, ninety miles west of Oslo in southern Norway. Norsk Hydro-Elektrisk K vaelstofaktieselskab produced the rare liquid as a byproduct of hydrogen electrolysis for synthetic ammonia production.1282 I.G. Farben, the German chemical cartel assembled by Bayer’s Carl Duisberg in the 1920s, owned stock in Norsk Hydro; learning of the War Office’s need it approached the Norwegians with an offer to buy all the heavy water on hand, about fifty gallons worth some $120,000, and to order more at the rate of at least thirty gallons a month. Norsk Hydro was then producing less than three gallons a month, enough in the prewar years to glut the small physics-laboratory market. It wanted to know why Germany needed so vast a quantity. I.G. Farben chose not to say. In February the Norwegian firm refused either to sell its existing stock or to incre...