How long will global uranium deposits fuel the world's nuclear reactors at present consumption rates?

Steve Fetter, dean of the University of Maryland's School of Public Policy, supplies an answer:
If the Nuclear Energy Agency (NEA) has accurately estimated the planet's economically accessible uranium resources, reactors could run more than 200 years at current rates of consumption.

Most of the 2.8 trillion kilowatt-hours of electricity generated worldwide from nuclear power every year is produced in light-water reactors (LWRs) using low-enriched uranium (LEU) fuel. About 10 metric tons of natural uranium go into producing a metric ton of LEU, which can then be used to generate about 400 million kilowatt-hours of electricity, so present-day reactors require about 70,000 metric tons of natural uranium a year.

According to the NEA, identified uranium resources total 5.5 million metric tons, and an additional 10.5 million metric tons remain undiscovered—a roughly 230-year supply at today's consumption rate in total. Further exploration and improvements in extraction technology are likely to at least double this estimate over time.

Using more enrichment work could reduce the uranium needs of LWRs by as much as 30 percent per metric ton of LEU. And separating plutonium and uranium from spent LEU and using them to make fresh fuel could reduce requirements by another 30 percent. Taking both steps would cut the uranium requirements of an LWR in half.

Two technologies could greatly extend the uranium supply itself. Neither is economical now, but both could be in the future if the price of uranium increases substantially. First, the extraction of uranium from seawater would make available 4.5 billion metric tons of uranium—a 60,000-year supply at present rates. Second, fuel-recycling fast-breeder reactors, which generate more fuel than they consume, would use less than 1 percent of the uranium needed for current LWRs. Breeder reactors could match today's nuclear output for 30,000 years using only the NEA-estimated supplies.

Editor's Note: This question was submitted by G. Peck of Seward, Alaska and will be printed in the March 2009 issue of Scientific American.

Dear editor,

I'm a great fan of Sciam and am usually content with the content. However, having done a bit of research on nuclear power myself, I found this months Ask the Experts article on global uranium deposits anything but expert. This answer lacks integrity at best and is otherwise simply misleading. First of all an expert would have pointed out that consumption of uranium deposits is rising, so while valid as an exercise, calculating future reserves at current consumption will overestimate reserves.

From: http://www.rcresearch.com.au/documents/uranium/reports/0/australia/
"There are 376 new nuclear reactors planned or proposed globally as of Dec ’08, up from 318 Aug ’08 (+58 units, +18%). The main increases are UAE (11), Italy (10), UK (6), Vietnam (6), and Poland (5). ... Currently there are 439 nuclear power reactors in operation and 39
under construction. A total of 61 new reactors are expected to be
commissioned by 2014."

Secondly Steve Fetter uses the NEA as his single source of information. This would be fine if the source were an independent organisation with balanced information. However, the NEA is an organisation which is focused on the expansion of nuclear power as an energy source. Deposits as reported by the NEA are presumed to be of equal quality, however the quality of deposits are known to vary and the highest quality deposits are consumed first and will finish in decades. This means counting tonnes of uranium left is not to count energy equivalent tonnes of uranium. The last paragraph of the article is simply unworthy of Sciam. Price is far from the only problem with these technologies. Fastbreeders are not technologically feasible now and safety concerns mean they might never become feasible. As for extracting uranium from sea water, this is a fallacy. The energy required is simply more than will be produced from the collected uranium.

See the following for an example of a more complete analysis of uranium deposits:
http://www.stormsmith.nl/publications/Energy%20from%20Uranium%20-%20July%202006.pdf

For the love of Sciam, please make sure your experts have more than 15 minutes to research their topic of expertise next time.

Thank you,
Chimed Jansen
Vrije Universiteit
Amsterdam

Climate change is a massive problem that needs big and bold solutions, says Professor Tim Lenton. In this week's Green Room, he outlines the reasons why "geo-engineering" projects, such as reflecting sunlight back into space, could help win the battle against dangerous climate change.

The climate is undoubtedly changing, and it is changing faster than many scientists thought it would, especially in the Arctic.

Regardless of the ineffectual Kyoto Protocol, carbon dioxide emissions from human activities increased by 3% per year during 2000-2006.

Even if we can globally get our act together and reduce CO2 emissions by 80% by 2050, we are still heading for at least a 2C (3.6F) warmer world.

Who today is willing to commit future generations to collectively controlling the planetary thermostat?

This may be too much for elements of the climate system, including the Arctic sea ice and Greenland ice sheet, which could pass a tipping point on the way there.

The resulting climate change may well be "dangerous"; and if so, mitigation alone cannot avoid it.

But reducing CO2 emissions is not the only way. There are two "geo-engineering" approaches that could complement it: reflecting more sunlight back to space, or actively removing CO2 from the atmosphere.

Both aim to cool the planet; but one tackles the symptoms (higher temperatures) while the other, like mitigation, addresses the underlying cause (elevated CO2 concentrations).

But do these approaches really offer a silver bullet to solve the climate problem?

From mirrors in space to reflective roofs on our homes, reducing the amount of sunlight the Earth absorbs could counteract (to varying degrees) the extra heat radiation trapped by the increasing greenhouse effect.

For a given option, the strength of the cooling effect is determined by the change in reflectivity applied, the area it is applied over, and the altitude of application.

Air-cooled

Among the most potent options is injecting tiny sulphur particles into the stratosphere to scatter more sunlight.

In principle, this could counteract the projected warming resulting from the future concentrations of atmospheric CO2 up to at least twice the pre-industrial level.

Volcanoes show us what impacts some schemes might have

Such options might be developed within decades, and if they are deployed, their cooling effect would be very fast acting.

However, the cooling effect will also be short-lived, so if activities start on a global scale (which is necessary for them to be effective), there will need to be a commitment to maintain them for many centuries.

Stopping the activity would result in dangerously rapid climate warming, far worse than the steadier warming they were designed to counteract.

In effect, such technologies imply an unprecedented duration and level of international co-operation to maintain them.

Who today is willing to commit future generations to collectively controlling the planetary thermostat?

There are also undesirable side effects of this kind of medicine.

We know from past volcanic eruptions that reducing incoming sunlight weakens the water cycle, promoting drought in regions including India and the Sahel in northern Africa.

Growing attraction

So, what about the other geo-engineering approach?

There is no simple silver bullet among the geo-engineering options, but some could make an invaluable contribution

From planting trees or fertilising the ocean to chemical "scrubbing", there are several ways of creating carbon "sinks" to remove CO2 from the air.

In general, these options act more slowly and progressively than those that reflect sunlight.

CO2 removal activity has to be ramped up and maintained for several decades (and in some cases centuries) for it to have a significant effect on atmospheric CO2 and climate.

For it to be truly effective, the carbon must be transferred to a long-lived reservoir such as charcoal in soil, or geological storage for liquid CO2.

The proposals vary greatly in their potential effectiveness, which of course also depends on the area or scale of application.

Perhaps the most potent option, on the century timescale at least, is to grow plants to get CO2 out of the air and then convert their biomass to both charcoal and (bio)fuels.

Hold the climate fixes

The charcoal would be added to soil as "biochar" and the fuels used for combustion, but ideally with capture of the CO2 and transfer to geological reserves.

The attraction of such an approach is that it produces energy and heat as well as agricultural benefits, and might (according to some estimates) generate revenue.

Most, if not all, other geo-engineering schemes will cost money and thus rely on willingness to pay.

The climate side-effects of creating carbon sinks are generally less than for sunlight reflection options, but the socio-economic side effects may be considerable.

Follow the money

So where do we go next? Many fear that even discussing geo-engineering options undermines mitigation efforts.

But mitigation alone may not be able to avoid dangerous climate change, so we must consider what other activities could complement it.

There is no simple silver bullet among the geo-engineering options, but some could make an invaluable contribution.

Adding iron to sea water could stimulate the growth of algae

Potent and rapidly deployable sunlight reflection options could be held in reserve as an emergency response should we get some early warning of approaching tipping points.

The creation of significant CO2 sinks is just as valid as reducing the sources of the greenhouse gas, because the atmosphere cannot tell the difference.

Together, they give the best chance to stabilise atmospheric CO2 and ultimately reduce it.

But economic assessment of the various geo-engineering options is badly needed, because cost will likely determine which, if any, are deployed.

Ultimately climate change is a problem of risk management. There is already a substantial risk of dangerous impacts, even if we do start meaningful global mitigation of CO2 emissions.

Given this context we must weigh up the balance of risks of using, or not using, geo-engineering.

Professor Tim Lenton is an Earth system scientist based in the School of Environmental Sciences, University of East Anglia, Norwich, UK

The Green Room is a series of opinion articles on environmental topics running weekly on the BBC News website

All geo-engineering projects contain great uncertainty and applying them risks compounding the many challenges facing humanity instead of alleviating them. To be effective such efforts will require great effort and international cooperation. If this effort were applied to mitigation, through for example, reducing damage to primary forests, reducing fossil fuel consumption, changing dietary habits, controlling population, etc, the effective change in CO2 levels might well be the same. Mitigation has the additional benefit that most methods result in positive 'risks' which may aid humanity, such as protecting biodiversity, reserving fossil fuels for alternative uses or alleviating poverty.
Chimed, Amsterdam

I decided to collect my statements on various topics in one place, hence this blog. Why choose The First Law as a title? First of all this is a reference to The First Law of thermodynamics which states that energy can neither be created or destroyed, only transformed.

This can be applied on the individual level or the level of society. On the individual level I see this as a statement that transformation has to occur in a sustainable manner. Destroying what you don't like about yourself won't work. While trying to reinvent yourself won't work either. Both these processes divide the mind delivering instability at best and insanity at worst. Transformation has to come from within the working of the ordinary state of mind.

My interpretation of its application to society is that to bring about the change you desire you should neither attempt to create an external society to replace the original, nor should you destroy the existing society in the hopes of replacing it. Rather society must be transformed from within. External societies which hope to show the way are ridiculed or ignored by the masses. Or if they are acknowledged the life styles of those societies are seen as too radically different and the paths to them are seen as too difficult to follow. On the other hand destructive changes focus solely on the problems with the current society without cultivating a meaningful alternative. This means their success will inevitably be their destruction with the additional cost of disillusioning, alienating and causing suffering to both members and the society they objected. Of course acting from within has its own dangers. Conformity is subtle and while one may begin with the idea of changing society, once integrated the seduction of security, distraction of the meaningless and comfort of sloth can dull any ambitions of change you may have had. Time will tell.

So how does this relate to me? Well I see several problems in our current society which I would like to acknowledge, describe and ultimately change. Not alone of course, because in a society nothing happens alone, however every group is made of individuals and its important to make statements yourself once in a while. Voting once every few years alone is to do mere lip service to democracy. The great freedom of democracy is that we can make our views known and spread ideas which, if they reach critical mass, become part of politics and have a chance to be realised.