Uranium resources worldwide
By Bruno Comby, President of EFN
When speaking of uranium resources, one must distinguish between the proven resources (already discovered, also called "known conventional resources") the additional reserves (not yet discovered, but that quite certainly exist, also called "undiscovered conventional resources") and the speculative resources (which may exist, but more uncertainly).
The amount of uranium available also depends on the price one wishes to pay for it. If you are willing to pay more, then miners will be motivated to search out and win uranium with a greater expenditure of effort and money, using more expensive technology, exploiting it at lower concentrations and at deeper depths.
We are today only at the beginning of uranium exploration, similar to the case for oil at the beginning of the 20th century. Most oil fields were then still to be discovered, and in the first half of the 20th century both the proven and estimated reserves kept increasing for several decades.
The NEA (Nuclear Energy Agency) is among the most competent sources of information on this topic. The NEA publishes every year with the IAEA a document called the NEA Red Book "Uranium Resources, Production and Demand."
The Red Book tabulates Known Conventional Resources and "Reported Undiscovered Conventional Resources", and mentions unconventional uranium resources in passing. The latter are mainly the uranium recoverable from phosphate mineral and the uranium dissolved in the seas.
Thorium is also mentioned in passing. Thorium reserves and resources are estimated to be well over 4.5 million tons. Curiously there is no thorium dissolved in the seas.
The price of "yellowcake" U3O8 on today's spot market is about 20 US$/pound (see http://www.uxc.com/review/uxc_prices.html ). Since 1 pound = 0.45 kg, and 1 kg U3O8 contains about 850 g of U, we find that the current price of uranium is about 50 US$/kg).
The Red Book tells us that Known Conventional Resources of uranium are about as follows:
3,500,000 tons if one is willing to pay up to US$ 80/kg, and
4,500,000 tons if one is willing to pay up to US$ 130/kg.
Presumably a lot more can be found and mined if we are prepared to pay a higher price. Paying more for uranium would not significantly increase the price of kiloWatt-hour of electricity to the consumer, for the cost of uranium today constitutes only 5% of the cost of the kWh. That is, if the cost of uranium were to double, the cost of a kWh would increase only by 5%.
Reported undiscovered conventional resources (table 8 of the Red Book) :
Estimated Additional resources - Category II . . . . . . . . . 2.25 Mt
Speculative Resources . . . . . . . . . . . . . . . . . . . . . . . . . 7.5 Mt
Total (additional+speculative). . . . . . . . . . . . . . . . . . .. .10 Mt
conventional uranium reserves worldwide
(proven+additional+speculative) are about 15 million tons
at a price up to US$ 130/kg.
NON-CONVENTIONAL Uranium reserves: in phosphate mineral and dissolved in sea water
The Non-conventional Resources are:
- about 22 million tons of uranium which may be recoverable from phosphate mineral, and
- about 4000 million tons of uranium which are dissolved in the seas, discussed below:
At the present rate of consumption of 60 000 tons per year, the 4.5 million tons of PROVEN reserves (Known Conventional Resources) available at prices up to US$ 130/kg (about twice the present spot price) would last about 75 years.
Similarly, the 10 million tons of ESTIMATED reserves would last another 165 years, and the 22 million tons of NON-CONVENTIONAL reserves which might be recovered from phosphate mineral would last an additional 365 years. These reserves might add another 500 years to our supply of uranium for our present fleet of reactors, at a cost compatible with an economical use of nuclear energy.
Uranium dissolved in sea water: about 4 billion tons. A great deal of energy must be invested to win uranium from the sea, more energy than can be obtained by the fission of uranium-235 alone. So it is useless to seek uranium in the seas if we are limited to the fission of U-235. Uranium dissolved in the seas is a resource only if we can burn significant amounts of uranium-238; that is, if U-238 is loaded in fast neutron reactors.
Source : NEA/IAEA RED BOOK 2003 (the RED BOOK "Uranium 2003: Resources, Production and Demand" can be ordered from the NEA - www.oecd.org, click on online bookstore)
A few implications about the future and the necessity of fast neutron reactors:
Our world will begin to run out of oil and gas in a few decades' time, and of coal in a century or two. Without energy, our industrial civilization will not survive. Nuclear energy is the ONLY source of energy which is mature and capable of replacing a significant portion of the large amounts of carbon fuels burnt today.
Therefore, as the flow of oil diminishes and gas and coal are used up, it is very likely that we shall see a considerable expansion of nuclear power in the coming decades.
It is therefore important to take a look at the life of our uranium reserves, not only based on today's fleet of reactors, but also in the highly probable case of a "nuclear intensive" scenario.
When oil becomes rare in the next few decades, the nuclear installed capacity may be expected to expand 10-fold, say, to produce not 7% of the world's energy as it does today but perhaps 70% in 2050 and afterwards. The uranium reserves which are enough for 600 years at today's rate of consumption in our 450 reactors would then last only 60 years while fueling 4500 reactors (of one gigawatt each), using today's reactor technology. In this "nuclear intensive" scenario, there may seem to be no immediate risk of U shortage, but in the medium-term a shortage would become evident. We might then look forward to only one more generation of water-moderated reactors such as BWR's APR's, ACR's or EPR's which have a life span of about 60 years. With reprocessing and intensive re-enrichment of unburnt U235, at most one more generation of water-moderated reactors might be envisioned.
Although there is no short-term risk of U shortage, there is an important medium-term risk - in half a century or so. [When our grand-children reach the age we have today]
Fast neutron reactors such as MONJU in Japan, BN600 in Russia, and PHENIX in France are proven technology. PHENIX for example has been running for more than 30 years, and an industrial prototype was built and operated successfully: SUPERPHENIX, a 1400 MW fast neutron reactor, ran for 11 years before it was unfortunately shut down in 1997, prematurely and permanently, for strictly political reasons. Fast neutron reactors burn uranium much more efficiently, producing at least 50 times more energy from a given amount of natural uranium than today's water-moderated reactors. They can run on natural or depleted uranium and burn all sorts of plutonium, even degraded plutonium (i.e. recycled plutonium) and also long-term actinides such as neptunium, americium, curium, thus decreasing the long-term amount and toxicity of the nuclear waste.
With fast neutron reactors, the estimated and non-conventional uranium resources from phosphate deposits described above would be enough for 30 000 years of use. This would transform nuclear energy into a sustainable source of energy in the very long term.
Fast neutron reactors can be expected to become a major provider of energy in the next decades. Fast neutron technology is probably the ONLY SOLUTION, at least in the coming decades, and this equation will need to be solved in very few years from now. Therefore reactors such as MONJU, BN600, the EFR, and other fast neutron reactors SHOULD CONTINUE TO OPERATE (MONJU) or be developed (EFR) to maintain our expertise and build experience and to assure the continued development of sodium reactor technology.
To abandon MONJU and to decline to develop the EFR (European Fast Reactor, a 1500 MW sodium cooled reactor, successor to PHENIX and SUPERPHENIX) would be in total contradiction with our commitment to sustainable development.
Fast neutron reactors are the key to sustainable development and to the continuation and the development of our civilization. At this time no alternative is in sight, and the time horizon is a few decades.
Research and development on nuclear fusion, in particular the ITER project, should be continued although it is still extremely uncertain whether nuclear fusion will ever be commercially feasible, at least in this century.
An alternative, which is seriously considered by countries which are poor in natural uranium, but rich in thorium deposits, like India, Turkey, etc., is to use thorium reactors, which can run both on thermal or fast neutrons. A nuclear energy industry based on thorium, parallel to that based on uranium, is quite feasible and has been demonstrated. The state of industrial development of this thorium-based industry, however, is not yet as advanced as that based on uranium, and development work is still needed. India is now the world leader in this field, and is on its way to have the complete thorium cycle operating in a few years. As thorium in Earth's crust is about twice as plentiful as is uranium, the prospects for a sustainable nuclear energy are doubly justified when considering thorium resources.
In order to ensure the continuation, if not the survival of our civilization after 2050, fast neutron fission is the only PROVEN and SAFE technology today. The various fast neutron reactor proposals of Generation IV should be urgently developed - before it is too late.
In 1983 Professor Bernard L. Cohen, University of Pittsburgh (USA) showed:
(1) that one ton of uranium completely fissioned (with fast neutron reactors) at a thermodynamic (Carnot) efficiency of 40% produces one GigaWatt-year of electrical energy, and
(2) that uranium dissolved in the seas is replenished by 32 thousand tons per year of uranium eroded from the crust and carried down by the rivers.
Cohen argues that the potential 32 000 GigaWatt-years far exceeds any reasonable estimate of the long-term needs of a world population of 10 billion. Thus, the uranium dissolved in rivers flowing to the sea constitute a sustainable source of energy, that is, one that cannot be exhausted.
Uranium can therefore be considered as a sustainable form of energy.
In fact nuclear energy is the ONLY source of energy available that is able to ensure the continuation of our civilization when oil and gas resources will be depleted, in a few decades from now.