to tender, and the contract was awarded to the lowest bidder, G. Albin Pehrson, on March 16, 1943. Pehrson produced a series of standard house designs based on the Cape Cod and ranch-style house design fashions of the day. Pehrson accepted the need for speed and efficiency, but his vision of a model late-20th-century community differed from the austere concept of Groves. Pehrson ultimately had his way on most issues, because DuPont was his contractor, not the Army. The resulting compromise would handicap Richland for many years with inadequate sidewalks, stores and shops, no civic center, and roads that were too narrow. Unlike Oak Ridge and Los Alamos, Richland was not surrounded by a high wire fence. Because it was open, Matthias asked DuPont to ensure that it was kept neat and tidy. Construction Construction of the nuclear facilities proceeded rapidly. Before the end of the war in August 1945, the HEW built 554 buildings at Hanford, including three nuclear reactors (105B, 105D, and 105F) and three plutonium processing plants (221T, 221B, and 221U). The project required of roads, of railway, and four electrical substations. The HEW used of concrete and of structural steel. Construction on B Reactor commenced in August 1943 and was completed on September 13, 1944. The reactor went critical in late September and, after overcoming neutron poisoning, produced its first plutonium on November 6, 1944. The reactors were graphite moderated and water cooled. They consisted of a , graphite cylinder lying on its side, penetrated horizontally through its entire length by 2,004 aluminum tubes. containing of uranium slugs. They had no moving parts; the only sounds were those of the water pumps. Cooling water was pumped through the tubes at the rate of . This was enough water for a city of a million people. Production process Uranium arrived at the Hanford Engineer Works in the form of billets. In the Metal Fabrication and Testing (500) Area they were extruded into rods and machined into cylindrical pieces, in diameter and long, known as "slugs". The initial charge of the three reactors required more than twenty thousand billets, and another two thousand were needed each month. Uranium was highly reactive with water, so to protect them from corrosion by the cooling water they were canned in aluminum a molten bath of copper–tin alloy, and the cap was arc welded on. A defective can could burst and jam