Physical Insights

An independent scientist’s observations on society, technology, energy, science and the environment. “Modern science has been a voyage into the unknown, with a lesson in humility waiting at every stop. Many passengers would rather have stayed home.” – Carl Sagan

Posts Tagged ‘uranium resources

Funny Numbers.

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This is a chunk extracted from a recent post by Matt in the nuclear energy debate that is currently happening over at TalkClimateChange forums.

Rod Adams has already responded in the debate with his piece – but I was astonished by just how inaccurate these numbers are – so I wanted to have a look at these figures, and remind everyone exactly what the more correct figures are.

“Starting from this: A standard 100mw/eh nuclear reactor requires in the region of 160 tonnes of uranium fuel – processed from around 16 million tonnes of rock – each year.”

“100 mw/eh” ? Is that supposed to mean 100 MWe ? A standard nuclear power reactor, in the form in which they’re normally encountered, generates far more than 100 MWe – 1000 MWe is typical, for the standard currently popular designs of nuclear power reactors.

The amount of uranium required to fuel a nuclear power reactor, using currently widespread technology, i.e. LEU fuelled LWR, equates to about 200 metric tons of uranium oxide, before enrichment, per gigawatt-year of energy obtained.

Assuming 0.15% uranium oxide in the ore, that’s 133,300 tons of ore that needs to be processed per GW-yr.

“And knowing that An average [UK] home utilises 4700 kWh per year

The 100MW can provide 876,000,000 kWh. There are 25 million homes in the UK, or 117,500,000,000 kWh demand. Therefore to provide for just the electricity needs of the UK, requires 134 nuclear reactors.

(In reality, electricity demand is not 24/7. Since nuclear has to run continuously, you would need more fuel that the 134 x 160 = 21,440 tonnes of uranium per year.)”

Household electricity demand is estimated at 117.5 TWh. The actual total electricity consumption in the UK was 345.2 TWh as of 2004, according to the World Factbook – but this kind of estimate as made above isn’t too bad – it gives the correct order of magnitude.

Assuming that power reactors generate 1 GWe with a capacity factor of 90%:

345.2 TWh / (1 GW * 90% * 1 year) = 44 reactors needed to supply the UK’s electricity demand.

Obviously, it’s not entirely efficient if you somehow decide you want to use excess nuclear capacity to meet all the peak-load demand.

“(Note that this is also 134 x 16M = 2,144,000,000 or just over 2 billion tonnes of rock that need processing, transporting etc)”

133,300 tons of ore needs to be processed per GW-yr, assuming 0.15% uranium oxide content.

So, that’s 5.25 millon metric tons of uranium ore per year to supply the UK’s electricity.

The coal alternative is 177 million metric tons of coal.

“The McArthur River project is the world’s largest known high-grade uranium deposit. It is presently being developed to allow the start of production in late 1999. Located in northern Saskatchewan, Canada, the deposit is estimated to contain 416 million pounds of U3O8”

416 million pounds = 188 694.426 metric tonnes. Therefore the world’s largest known reserve of uranium has enough fuel to provide electricity to the UK domestic market – ignoring offices, industry, manufacturing and railways – for just under 9 years.”

Supplying the UK’s entire electricity needs from nuclear energy would consume about 8000 metric tons of uranium oxide per year.

That 416 million pounds of uranium oxide has an energy content corresponding to the UK’s total electricity consumption, at current levels, for 24,000 years.

I won’t really hold Matt responsible for such glaring inaccuracies, though – the bad data was taken straight from The Ecologist, here .


Written by Luke Weston

April 6, 2008 at 12:00 pm

Uranium extraction from coal waste.

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Sparton Resources has been making headlines recently, with their pilot-scale demonstration of Uranium leach extraction from coal fly ash waste.

A few extracts from the linked press releases, to set the background on this issue:

“Historical analytical data from the period 1992 to 1995 indicate that the fly ash in these deposits contains between 92 and 154 ppm U3O8. The bottom ash contains similar values. These are similar to those in a number of in situ leach type uranium deposits under evaluation in various parts of the world.”

“Research data by the two companies indicates that other very large radioactive waste ash deposits in the region may also be potential evaluation sites for the program. Work continues towards concluding additional agreements similar to the Ajka contract.”

“Meanwhile, Sparton said that a drilling program on the fly ash waste pile at Xiaolongtang was completed in September and the results indicated that pile is on average some 17 metres thick and contains around 5.3 million tonnes of ash. In July, Sparton suggested that the stockpile could contain up to 10 million tonnes of coal ash. Staff at the power plant had previously estimated there were some 5 million tonnes of ash. Initial tests by Lyntek indicated that the material contains some 0.46 pounds of U308 per tonne of ash (160-180 parts per million uranium), suggesting a total of some 2085 tonnes U3O8 (1770 tU) are contained in the Xiaolongtang ash piles.”

An furthermore, some interesting analysis of the value and scale of these Uranium resources, from Atomic Insights:

“It takes about 200 tons of natural uranium to power a 1000 MWe reactor for a year, so the ash pile mine could supply between 6-8 reactor years of fuel, producing about 48-64 billion kilowatt-hours of emission free electrical power. If you assume that power is sold for the average value in the US of 8.5 cents per kilowatt hour, the ash pile would help produce electricity worth 4-6 billion dollars.

I am sure that Sparton would have liked the price of uranium to have remained at or near its peak of $140 per pound – that ash pile would then be worth as much as $450 million dollars. However, uranium prices have dropped pretty quickly during the past few months; the current price listed at UXC is about $78 per pound. Even at that price, the uranium from a single ash pile might be worth as much as $250 million. Not bad for something considered to be at best a nuisance and at worst an environmental contaminant.”

Not bad at all, huh?

There’s also the possibility of economical extraction of molybdenum, vanadium and other metals of industrial interest – many of which are potential environmental hazards, in the fossil fuel waste, as well.

In 1997, the USA generated 1800 TWh of electrical energy from coal combustion, and generated 95 million tons of coal ash-type waste in the process.

Assuming 180 ppm Uranium in that material, that’s a fairly generous figure but not unheard of, that’s 17100 tons of Uranium, or enough uranium to fuel current technology, inefficient, uranium-235-fuelled nuclear power reactors for 86 GW-years, or 749 TWh, 42% of the energy output that was originally released in burning the coal.

When the Thorium content is considered, Generation IV or breeder reactors, the Uranium-238 content, or reprocessing are considered, the the coal ash waste has more energy accessible in it than you get burning the coal in the first place!

Here in Australia, we’re burying about 117 tons of Uranium each year, just in the Latrobe Valley in Victoria.

Australia exported 194 million tons of coal in 2000/2001 – hence as much as 349 tonnes of Uranium and 1358 tonnes of Thorium could conceivably be added to accepted uranium export figures, given a Uranium concentration of say 1.8 ppm in the coal. Such a quantity of natural uranium contains
2.5 tons of Uranium-235 – the equivalent of 39 simple vHEU-based Hiroshima-style nuclear weapons.

Given that nations including China have access to this technology, and are using it, and given that exports of mined uranium are always accompanied by concerns and outcries over the potential for weapons use, and the need for agreements to safeguard non-proliferation, why don’t we have nuclear nonproliferation safeguards in place for Australia’s coal exports?

I expect that other Uranium exporting nations such as Canada have similar scrutiny paid to their Uranium export industry.