MINING FOR URANIUM Shinkolobwe

The name rises as a phantom from the heart of the Congo. The dawn of the nuclear age began there, though no one knew it at the time. King Leopold II of Belgium claimed the Congo as his colony during the surge of European colonization in the 1870s, promising to run the country for the benefit of the native population. Instead, he turned it into a giant slave camp as he raped the country of its riches. Leopold didn’t care much about mineral wealth, preferring the easy riches of rubber, but after he died in 1909, the Belgium mining company Union Miniere discovered ample resources of copper, bismuth, cobalt, tin, and zinc in southern Congo. The history-changing find, though, was high-grade uranium ore at Shinkolobwe in 1915. The real interest at the time was not in uranium—it had no particular use—but in radium, the element the Curies discovered and made famous. It was being used as a miracle treatment for cancer and was the most valuable substance on earth—30,000 times the price of gold (1). Radium is produced from the decay of uranium after several intermediates (see Figure 8.3 in Chapter 8), so it is inevitable that radium and uranium will be located together. The true value of the uranium would not be apparent until the advent of the Manhattan Project to build the atomic bomb during World War II.

Edgar Sangier, the director of Union Miniere, which owned the mine at Shinkolobwe, hated the Nazis and was afraid—correctly, as it turned out—that they would invade Belgium. In 1939, as Europe was sliding into war, Sangier learned that uranium could possibly be used to build a bomb. He secretly arranged to transfer 1,250 tons of the uranium ore out of the Congo to a warehouse in New York City. There it sat until 1942, when General Leslie Groves, the man whom President Roosevelt put in charge of the Manhattan Project, found out about it

and arranged to purchase it. Throughout the war, shipments of uranium continued from Shinkolobwe to the United States to be used in building the atomic bomb. The veins of uranium ore at Shinkolobwe were the purest ever found on earth—up to 63% uranium oxide, more than 200 times as rich as most uranium ores. Even the mine tailings1 could have up to 20% uranium. Without this incredibly rich ura­nium ore, it is doubtful that the United States could ever have developed the atomic bomb, at least not in time to end World War II in Japan. The mine at Shinkolobwe provided two-thirds of the uranium and most of the plutonium (derived from neu­tron bombardment of uranium) for the two bombs dropped on Japan (1).

The only other source of uranium known at the time was at St. Joachimstal in the Krusne Hory (Cruel Mountains) in the former Czechoslovakia. This is where Marie Curie got the pitchblende that led to her isolation and discovery of polonium and radium in 1898 (see Chapter 2). Hitler annexed the Sudetenland in Czechoslovakia in September 1939 and inadvertently gained the uranium ore there. Hitler also cap­tured some uranium ore from Shinkolobwe that was on the docks in Belgium when he invaded in May 1940. There was great fear in the United States and its European allies that Germany was trying to build an atomic bomb, and indeed it was working on bomb technology under the direction of Werner Heisenberg, but never came close to developing one. The closest they came was an incomplete reactor (2).

In one of his final acts before committing suicide, Hitler shipped 1,235 pounds of uranium oxide by U-boat to Japan to help them build an atomic bomb. The uranium was left over from their research in nuclear fission and presumably came from the tailings dumps at St. Joachimstal. But the war in Europe ended before the submarine arrived in Japan, and the commander headed to North America to surrender to the US Navy. In a historical irony, the uranium most likely ended up in one of the bombs dropped on Japan (1).

General Groves thought that uranium was an extremely rare element and he wanted to corner the world market for the United States, but he was wrong. It turned out to be one of the most common minerals on earth, about 40 times as abundant as silver and more abundant than tin (3). Uranium was formed in the cataclysmic explosions of massive stars known as supernovas and spread through­out the universe. As the earth coalesced from the rock, dust, and gas surrounding the sun, the uranium became part of the rocky interior of the earth. The heat from its natural radioactivity was, and still is, largely responsible for the molten center of the earth, helping to make the earth a livable planet. Through the long geological history of the earth, magma flows, plate tectonics, and other physical and chemical processes led to deposits of uranium in 14 different categories of rock structures, including rich veins such as at Shinkolobwe and St. Joachimstal, unconformities, sandstones, and conglomerates (4).

Shiprock

The reddish spire rises like a ghostly ship from the high desert lands of the Colorado Plateau in the Four Corners region where Colorado, Utah, Arizona, and New Mexico meet. To the Navajo Nation that encompasses Shiprock and surrounding areas, it is a sacred place. But the environs of Shiprock are also the home of Leetso, the powerful yellow monster as it is known to the Navajo (Dine), but uranium as it is known to the rest of us (5). In 1948 the US Atomic Energy Commission announced that it would pay a guaranteed high price for all the ura­nium that could be found in the United States to reduce its dependence on the Congo for uranium to build its nuclear arsenal. This led to a mining boom in the United States, centered on the Four Corners area, much of it in the Navajo lands. Over two decades, peaking in 1955-1956, uranium was mined from this area, producing the necessary ingredients for the plutonium bombs in the arms race with the Soviet Union, as well as the fuel for the nascent nuclear power industry. According to an Environmental Protection Agency (EPA) study done in 2007, there are 520 abandoned uranium mines in the Navajo Nation resulting from the flurry of mining activity, which are now being cleaned up as Superfund sites (6).

The mining took a toll in human lives, though it was far worse at Shinkolobwe and at St. Joachimstal—after it fell into Russian hands after the war and Stalin needed uranium for his bomb development—than in the Four Corners area. The Navajo were eager for the jobs provided by the uranium mines but were not pro­vided safe working conditions, even though it was known at the time that radon in uranium mines could cause lung cancer. The simple expedient of ventilating mines to reduce the radon levels made them much safer, but this was not routinely done until about 1960.

Underground miners who smoke have a far larger risk of lung cancer than those who do not (see Chapter 8). The Navajo workers smoked far less than the white workers and had far lower rates of lung cancer. Age-adjusted annual mortal­ity rates for lung cancer in Native Americans from New Mexico (Navajo, Pueblo, and Apache) rose from 5.3 (per 100,000) in 1958-1962 to 10.8 in 1978-1982. The white population had a far higher rate, however, going from 38.5 to 70.4 during the same periods because of higher smoking rates (7). The rate for Navajo people may be even lower than for Native Americans in general, since the age-adjusted lung-cancer mortality rate for Navajos was 4.8 in 1991-1993 (8). These are general lung cancer mortality rates, not specifically for miners. Navajo who were uranium miners had far higher rates of lung cancer. Among 94 Navajo who were diagnosed with lung cancer between 1969 and 1993, 63 had been uranium miners. The rela­tive risk for the miners was 28.6 compared to non-mining control populations of Navajo (9).

The US Congress passed the Radiation Exposure Compensation Act (RECA) in 1990 to compensate former miners who developed lung cancer or other lung dis­eases attributable to uranium mining. The RECA was amended in 2000 to reduce the radon exposure limits to qualify for compensation and to increase the com­pensation to $150,000 (10). As of September, 2013, 5,893 claims for compensation from uranium miners had been accepted and paid (11).

The traditional form of mining done in the Navajo Nation and other places was vertical or horizontal shaft mining, where miners dug into the earth and extracted the uranium ore. It is worth putting the danger to uranium miners in context compared to underground coal mining at the time. Mining accidents killed 450 coal miners annually in the United States in the 1950s, and black lung disease killed over 2,000 miners annually from 1970 to 1990 (see Chapter 3). While the incidence of lung cancer in Navajo and white miners was unneces- sary—and could have (and should have) been avoided with proper ventilation of the mines—the hazards of uranium mining pale compared to the hazards of coal mining. There were about 5,900 miners who developed lung cancer or other lung diseases (though many survived) over roughly 20 years of uranium mining compared to about 2,500 annual coal miner deaths during this time. This min­ing was done before the days of the EPA and the MSHA (Mine Safety and Health Administration), which now make all kinds of mining much safer for the workers and for the environment.