Uranium update — a look at uranium
Michael Forrest talks to Steve Kidd, Director of Strategy and Research at the World Nuclear Association, London, UK.
The ever increasing demand for energy and the effects of its carbon footprint all feature in the debate about global warming. Although the science of carbon dioxide generation and its role in climate change is no longer seriously challenged, there are many aspiring people in the developing world that see this as no reason to curtail their economic growth and the improvement in lifestyles that it brings, while those in developed countries continue to consume most of the world’s energy.
Although renewable power is welcome, the scale of its contribution in the medium term will not meet current global energy requirements. Wind power is much favoured, but its variable output (50% at best, 30% on average, according to the weather) does not provide the base load. In many countries the provision of this base load is met by the burning of hydrocarbons. The obvious alternative is nuclear power.
The primary fuel for nuclear reactors is uranium, and although exploration during the past 30 years has been low, there are substantial known deposits and increasing uranium production. Exploration has revived and in the two years to 2007 it added 15% to resources.
Steve Kidd, Director of Strategy and Research at the World Nuclear Association, London, UK, says, ‘Uranium is not a rare metal, it is about as common as zinc or tin. World zinc production is 740,000t [source US Geological Survey] whereas mineduranium production is around 40,000t, with enough resources for over 100 years. This is based on uranium resources that can be economically recovered at US$80/kg (US$35/lb), well below the current market price, and provides a time-frame far in excess of those used for most metals, offering an unparalleled security of supply’.
He adds, ‘Using a price more akin to today’s spot price (US$64/lb in July), the International Atomic Energy Agency (IAEA) estimates that another five million tonnes could be included in reasonably assured and inferred resources, giving a 200-year supply at current consumption levels. These data do not take into account the more unconventional sources of uranium such as phosphate mining, which could add 22Mt of uranium as a by-product’.
The 65,000t of nuclear fuel used annually in nuclear power stations is sourced from operating mines and secondary supplies. The top seven producers, Cameco, Rio Tinto, Areva, Kazatomprom, ARMZ and BHP Billiton, produced 63% of the total 41,000t of mined uranium in 2007. In addition, there are a number of junior producers with a capacity of under 1,000t/y.
In 2003, the price of uranium began to rise strongly in response to demand and dwindling stockpiles that included diluted weapons-grade material. There was also a perception that nuclear power might be the answer to global warming, which created an expectation of increasing demand. Prior to that date, the spot price of uranium had been under US$20/lb since the early 1980s.
‘During the early 1990s the spot price was below the cost of production for most mines,’ notes Kidd. ‘The price reached US$140/lb in mid-2007, attracting new companies into uranium exploration, many of whom revived mining properties not looked at for decades.’
Although today supply and demand is reasonably balanced, the 41,600t of uranium contained in 49,000t of uranium oxide concentrate mined in 2007 accounted for 64% of utilities’ annual demand, with the remainder coming from reprocessed material and stockpiles that are now becoming depleted. Mined uranium can be enriched to provide the three to four per cent U-235 (the fissionable isotope in uranium, the remainder is U-238) required in processed fuel rods.
‘Increasing efficiencies through more productive running, higher capacity factors and reactor power levels, reduced the uranium demand per kWh by 25% over the 20 years from 1970 to 1990. These improvements are continuing by enriching the U-235 from 3.3% to four per cent and burning it harder or longer, leaving just 0.5% of U-235 in the spent fuel rods,’ comments Kidd.
Nevertheless, each gigawatt power equivalent (GWe) of increased capacity will require about 195t of mined uranium each year and three times this for the first fuel load. The high capital costs of nuclear stations and their low fuel costs (the cost of uranium is about 10% of coal on a contained energy basis) impose a regime on demand that is probably more predictable than any other mineral commodity. As reactors are most efficiently run at full capacity, their use tends to be more constant, despite other fluctuations in national economy or power demands.
Kidd cites the example of South Korea where, ‘Falling demand for power a decade ago resulted in increased nuclear generation and a decline in importing fossil fuels. Typically, some 36mkWh of electricity are produced from one tonne of uranium. This amount of electrical power from fossil fuels would require the burning of over 20,000t of coal or 8.5Mm3 of gas’.
There are 439 nuclear power stations operating in 30 countries with a combined capacity of 370,000MWe. They provide 16% of the world’s electrical energy. The amount of power these plants produce is increasing, not so much due to new reactors coming onstream, but because of growing efficiency. In the period 1999-2006, there was no net increase in the number of reactors, yet the power produced rose by 210TWh (1012), equivalent to 30 new large nuclear reactors.
Another factor in increased power production is operational availability. Almost one third of the world’s reactors have load factors over 90%, and more than two thirds do better than 75%, compared with about a quarter of them in 1990. For 15 years Finnish plants topped the performance tables, but now the USA now has the 25 most efficient reactors and is the largest producer of nuclear electricity.
Reactor technology has been steadily improving over the 50 years since the first commissioning of nuclear power plants. None of the first generation reactors built in the 1950s and 60s are operational (except in the UK), while the majority of the American reactors and many elsewhere are second generation. They are based on technology originally developed for naval applications.
Third generation reactors are now onstream in Japan, and have a standardised design for faster permitting and construction of a simpler, more rugged design. This has increased output and allows longer operating life, typically 60 years – and higher burn-up to reduce fuel use and waste. However, the greatest difference is that they incorporate passive safety features based on gravity, natural convection and resistance to higher temperatures which require no operational intervention.
A fourth generation of reactors is at the concept stage and offers higher outputs and greater safety. Technologies include light and heavy water, high temperature gas-cooled and fast neutron reactors.
There are around 34 new reactors under construction in 11 countries, notably China, Russia, South Korea and Japan. The IAEA has recently increased its forecast of nuclear power generation and anticipates 60 new plants in operation in the next 15 years, increasing global power to 17%. There are many more planned – over 90 in addition to those under construction – another 200 proposed. The impetus has been the Kyoto protocol, the international agreement on climate change and reducing greenhouse gas emissions.
The debate over nuclear, renewables and hydrocarbon-based power will continue. Each proponent will emphasise the effectiveness, power costs, capital costs, scale or green credentials of the power source. Trying to measure one against another will result in more heat than light, for example – should the cost of carbon sequestration be included in the price of hydrocarbon electricity? Should the price of decommissioning of nuclear plants be the responsibility of the generator and included in power casts? And should the cost of back-up generation be included in wind generated electricity?
In the meantime, global power consumption is rising along with global warming. The current world electrical power energy mix is – coal 39%, hydro 19%, nuclear 16%, gas 15%, and oil 10%, or 64% hydrocarbon based. In the UK, 19 reactors generate about one fifth of its electrical energy, and all but one will be retired by 2023. New generation plants are envisaged in the 2008 Government White Paper (Meeting the Energy Challenge: A White Paper on Nuclear Power). In the forward by UK Prime Minister Gordon Brown, he concluded that ‘the electricity industry should from now on be allowed to build and operate new nuclear power stations, subject to meeting the normal planning and regulatory requirements. Nuclear power is a tried and tested technology. It has provided the UK with secure supplies of safe, low-carbon electricity for half a century’.
World Nuclear Association