Rich, a student from Chicago, asks:
How much uranium is estimated to potentially exist? How many years of nuclear energy does this translate to for the operation of nuclear power plants?
The OECD Nuclear Energy Agency (NEA) and the International Atomic Energy Agency (IAEA) publish a comprehensive review every two years on uranium resources, production, and demand. According to the 2009 version of the "Red Book,"1 the known uranium resources total about 6.3 million tons U, including high cost resources (<260 USD/kg U). The OECD estimates that at the 2008 rate of uranium consumption, these resources would be sufficient to provide a 100 year supply.
Additionally, U occurs naturally in both the earth's crust and seawater at low concentrations: ~ 3 parts per million in the crust and 3 parts per billion in seawater. It is estimated that over 4 billion tons of uranium can be found in seawater, but it is currently un-economical to recover it since the concentration is so low. There are many active research programs around the world exploring U recovery from seawater, which would provide access to an enormous resource of uranium.
1 Uranium 2009: Resources, Production and Demand, A Joint Report by the OECD Nuclear Energy Agency and the International Atomic Energy Agency OECD, Paris, 2010.
Juan, a consulting engineer in New York, asks:
We know that nuclear energy has been the most efficient way to generate electricity to cover the demand of big cities. But, we found that risks are present. Therefore, my question is the following: Did you consider designing midi or micro reactors and locating them in different parts of big cities to minimize risks? If you did the study, was this study economically feasible?
This is a topic that is currently of great interest to the nuclear energy community, and there is a lot of research into the area of small modular reactors. The U.S. Department of Energy has an ongoing and active research program in Advanced Reactor Concepts (part of the Office of Nuclear Energy) that funds research into small modular reactors. This concept is gaining acceptance and has been endorsed by both President Obama and Secretary of Energy Chu. You can see a recent opinion piece by Secretary Chu which was published in Wall Street Journal here. A lot of the research is in the early stages and the economic feasibility is still being studied, but there is currently a bill in the Senate which was scheduled for debate before the Committee on Energy and Natural Resources earlier this week. This bill, Nuclear Power 2021 Act, is sponsored by Sen. Bingaman from New Mexico and calls for funding to develop a standard design for two modular reactors, one of which will not be more than 50 megawatts; obtaining a design certification from the Nuclear Regulatory Commission for each design by 2018; and obtaining a combined operating license from the Commission by 2021.