Uranium is widely distributed around the world in the earth’s crust and even in seawater. How much is available to power nuclear reactors, though, depends on economics as well as geology. As is true with virtually all kinds of geological resources, the amount that is available depends on the price people are willing to pay for it. There are more oil resources available at $100 per barrel than at $30 per barrel because lower quality resources become economically viable when the price goes up. Of course, the flip side is that the energy needed to get the resource goes up as the quality goes down. This is as true of uranium as it is of oil or gold. When the price goes up, exploration also goes up, so additional resources are found. With fossil fuel energy resources such as oil or coal, the cost of the fuel is the major part of the expense of producing power. With nuclear power, that is not true. Because so little fuel is used in a reactor, the cost of the fuel is only of sec­ondary importance to the cost of power produced by a reactor. According to the Energy Information Administration (EIA), the cost for variable operations and management (O&M), which includes the cost of fuel, is only 10% of the total lev — elized cost of energy from advanced nuclear reactors. In contrast, variable O&M cost is 57% for conventional natural gas power plants and 69% for conventional combined cycle natural gas plants (42). The major cost for nuclear power is the capital cost of building the reactor. Thus, the cost of nuclear power is fairly insen­sitive to the cost of uranium.

As an example, if the cost of uranium doubled from $50 per pound to $100 per pound ($110/kg to $220/kg), the fuel cost for a reactor would go up from 0.62 cents per kWh to 0.86 cents per kWh, raising the cost of electricity from an efficient nuclear reactor from 1.42 cents per kWh to 1.66 cents per kWh (43). Over the last five years, uranium spot prices have been volatile, ranging from about $100 per pound in late 2007 before the worldwide recession to about $40 per pound in mid-2010. As of early 2013, the spot price was about $42 per pound, but most uranium production is actually sold on long-term contracts to utilities with nuclear reactors. The long-term contract price in 2013 was $57 per pound, sufficient to produce uranium profitably in the United States via ISR methods for high-grade deposits (44).

Exploration for uranium has gone in phases. The major push in the 1940s and 1950s came from the military effort to build bombs in the Cold War. A second push for exploration came in 1974-1983 due to the need to power civilian nuclear reactors and a perception that uranium was a scarce resource, which turned out not to be true. Little exploration occurred over the next couple of decades as the price of uranium tumbled, but picked up from 2003 until the present because of the increasing interest in a “nuclear renaissance” and an increase in the price of uranium. Because of this additional exploration, from 2005 to 2006 the world’s known uranium resources increased by 17% (45, 46). So where is it found?

Every two years, the OECD Nuclear Energy Agency and the International Atomic Energy Agency publish the “Red Book“—a compilation of uranium resources, production and demand, with the latest edition published in 2010 (47). Identified resources include reasonably assured and inferred deposits of uranium; undiscovered resources include both prognosticated and speculative resources. Reasonably assured resources are known mineral deposits that are well character­ized by quantity and quality of ore, while inferred deposits have been geologically established but are not as well characterized. Prognosticated resources are based on expected deposits within a geological area that has some known deposits. Speculative resources are based on indirect evidence and extrapolation from types of geological formations that usually contain uranium. The identified resources are broken down in categories by the cost of uranium, since more resources are avail­able at a higher cost. The top ten countries in thousands of metric tons (tonnes, or 1.1 US tons) of uranium are given in Table 11.1. The availability of uranium is strongly dependent on the cost. At < $80 per kilogram there are 3.7 million tonnes available, but at < $260 per kilogram there are over 6.3 million tonnes.

The quality of the ores varies substantially in different countries. The highest grade ores ever found were at Shinkolobwe, with assays of over 60% uranium, but that is all gone. Canada has the world’s richest ores in Saskatchewan, with assays exceeding 20% uranium. Australia has by far the world’s largest resources and the largest mine in the world (Olympic Dam). Even though Olympic Dam has low grade uranium ore (0.05%), the mine also produces copper, silver, and gold, which increases the economic efficiency of the mine. Other mines in Australia have ores with concentrations greater than 0.1%. Nearly all of Australia’s uranium is available at $80 per kilogram (Table 11.1). Kazakhstan has mostly low grade ores in sandstone that are amenable to ISR mining, which can very efficiently extract low grade ores. Uranium in the United States is also mostly low grade sandstone deposits that are amenable to ISR mining (47, 48).

note: Reasonably assured and inferred deposits of uranium in metric tons ura­nium at different prices per kg of uranium. Source: Red Book 2009.

Actual production of uranium does not follow the same country order as the resources, though. While Australia has by far the largest uranium resources, it is the third largest producer, producing only 8,000 tonnes of uranium in 2009. The largest producer was Kazakhstan (29%), followed by Canada (20%), Australia (16%), Namibia (9%), Russia (7%), Niger (6%), and Uzbekistan (5%). About a third of uranium production is now done by ISR, with the rest by underground and pit mining. The United States is a net importer of uranium, producing less than 3% of the world’s uranium in 2008 but using about 28% of the total (47). The total world production for 2009 was about 50,000 tonnes, but the world’s reactors used about 69,000 tonnes (46). So where did the rest of it come from? Part of it came from stockpiles of uranium held by utilities and governments, some came from depleted uranium tailings that still have useful amounts of uranium, and some came from reprocessing spent nuclear fuel (see Chapter 9). But the largest amount came from a unique program to disarm nuclear warheads.