Uranium Supplies – Is there enough?

02Apr09

This post continues some of the reflections on the potential for nuclear to play a role in the supply of low carbon energy. Here we are considering the adequacy of uranium supplies.

Let’s start with estimates of global uranium reserves…

According to the Nuclear Energy Agency’s Red Book, there is 5.5 million tones of conventional identified uranium resource (which they classify as reasonably assured resources and estimated additional resources costing less than US$130/tonne uranium to extract). The majority of these resources are located in Australia, Canada and Venezuela.

The NEA estimate that there is a further 10.5 million tones of as yet unidentified uranium resource (which is estimated additional resources and speculative resources that are as yet undiscovered and which most likely will cost >US$130/tonne to extract). Again, the majority of these resources are thought to be located in Australia, Canada and Central Asia.

There is also an estimated 20 million tonnes of low grade uranium to be found in phosphate deposits. And a further 4.5 billion tonnes of uranium present in sea water – though in this latter case no such technology exists to extract that resource. The technical difficulties involved in extracting trace amounts of uranium from sea water are considerable – but they are not insurmountable.

There are also reserves of other nuclear fuels that can be used in nuclear reactors, most notably thorium. Thorium is three times more abundant in the earth’s surface than uranium. Current thorium reserves are in the order of 1.5 million tonnes and there is a further 6 million tonnes in estimated reserves. Turkey, Australia and India account for about two-thirds of the known global thorium reserves. Thorium is currently used in nuclear reactors in India. The 200MW Shidaowan high-temperature reactor which is currently under construction in China will also use thorium.

Now let’s consider the rate of consumption of uranium in a reactor…

The amount of uranium that is used to generate 1 MWhr of electricity in a nuclear is determined by two key factors:

  • the burnup rate – the rate at which uranium is converted to thermal energy, usually expressed as GWd/tonne uranium; and
  • the generator efficiency – the rate at which thermal energy is converted to electrical energy in a generator, usually expressed as a percentage.

Below, we calculate the amount of electrical energy that can be produced from uranium for various reactor types spanning Gen I to Gen +IV technologies assuming different levels of uranium supply. We show the burnup rate, the generator efficiency, electricity generation per tonne of fuel, and the number of years the fuel supply would last if we supplied all of the world’s current electricity consumption (about 19,000TWh) and all of the world’s forecast electricity consumption in 2030 (about 33,000TWh).

adequacey-of-uranium-supplies

So…Is there enough uranium? The answer depends upon how we frame the question.

Is there enough uranium to meet our current electricity needs, using current technology?

Yes, but only if we can exploit all of the estimated reserves. Current second generation technology, using current identified uranium resources, could supply about 44% of the world’s current electricity needs, but the uranium would be exhausted after 100 years. But if we considered estimated reserves plus the uranium in phosphate reserves, then current generation technology could meet the world’s current electricity needs for 300 years.

Is there enough uranium to meet our current electricity needs, using next generation technology?

Undoutedly, yes. If we use Gen III or Gen IV technology, even considering just the 5.5 million tonnes of identified reserves, we could supply all of the world’s current electricity needs for over 100 years in the case of Gen III technologies, and for over 600 years in the case of Gen IV technologies. If we consider also estimated unidentified reserves and phosphate deposits, those time frames would increase to more than 1,000 years in the case of Gen III technologies and more than 4,000 years in the case of Gen IV technologies.

But of course, our electricity consumption will not stay still, so…

Is there enough uranium to meet our future electricity needs using current technology?

No, not, if we consider just the identified uranium reserves. Gen II technology could meet 25% of our future 2030 electricity needs over 100 years, or all of those needs over 25 years. If we used all estimated reserves as well as phosphate deposits, then Gen II technology could supply electricity at 2030 levels for 173 years.

Is there enough uranium to meet our future electricity needs using next generation technology?

Again yes, but we would need to call on all estimated reserves. Even with the higher electricity needs forecast for 2030, Gen III technologies relying solely on identified reserves could supply all of the world’s electricity consumption in 2030 over 100 years. In the case of Gen IV technologies, the identified reserves would last about 400 years supplying electricity at 2030 levels. If we used the estimated reserves and phosphate reserves then we could supply the world’s total electricity needs on 2030 over a period of 500 years in the case of Gen III technologies, and 2,500 years in the case of Gen IV technologies.

But these questions avoid the important issue of equity.

Is there enough uranium to supply all of the world’s population with the same amount of energy as the average European using current technologies?

No, not even if we use all of the estimated uranium and phosphate reserves. The average European’s daily energy consumption is about 150KWh per person per day. Even if we used up all identified and estimated uranium and phosphate reserves, we would be able to supply just 17kWh/per/day, or 12% of our objective. And after 100 years, we would have exhausted our supplies.

Is there enough uranium to supply all of the world’s population with the same amount of energy as the average European using next generation technologies?

Yes, but only if we use Gen IV technology and all estimated uranium and phosphate reserves. If we used all estimated uranium and phosphate reserves in Gen III technologies we could contribute about 40% of our per capita objective and after 100 years we would have exhausted the world’s current estimated uranium reserves. But if we used Gen IV technologies, we could supply everyone in the world with 150kWh/per/day of energy for about 200 years.


So, is there enough uranium? If we simply want to supply a large proportion of the world’s current electricity needs, then yes just about, even using current Gen II technologies. If we want to supply a large proportion of the world’s future electricity needs, then yes, but we will need to commercialize Gen III technologies. And finally, if we want to provide everyone in the world with the same level of energy as an average European, then yes again, but in this case only if we can develop Gen IV technologies.

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One Response to “Uranium Supplies – Is there enough?”

  1. 1 SteveK9

    From David MacKays ‘Sustainable Energy – Without the Hot Air’

    Here’s what the World Nuclear Association said on the topic of uranium reserves in June 2008:
    “From time to time concerns are raised that the known resources might be insufficient when judged as a multiple of
    present rate of use. But this is the Limits to Growth fallacy, . . . which takes no account of the very limited nature of
    the knowledge we have at any time of what is actually in the Earth’s crust. Our knowledge of geology is such that we
    can be confident that identified resources of metal minerals are a small fraction of what is there.
    “Measured resources of uranium, the amount known to be economically recoverable from orebodies, are . . . dependent
    on the intensity of past exploration effort, and are basically a statement about what is known rather than what is there
    in the Earth’s crust.
    “The world’s present measured resources of uranium (5.5 Mt) . . . are enough to last for over 80 years. This represents a
    higher level of assured resources than is normal for most minerals. Further exploration and higher prices will certainly,
    on the basis of present geological knowledge, yield further resources as present ones are used up.”
    “Economically rational players will only invest in finding these new reserves when they are most confident of gaining
    a return from them, which usually requires positive price messages caused by undersupply trends. If the economic
    system is working correctly and maximizing capital efficiency, there should never be more than a few decades of any
    resource commodity in reserves at any point in time.”


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