(Updated February 2010)
In Canada, notably northern Alberta, there is major production of synthetic crude oil from bitumen extracted from tar sands. Alberta's tar sands are one of the largest hydrocarbon deposits in the world. Production from them is expected to grow strongly, but may limited by the amount of greenhouse gases emitted during extraction and upgrading of the bitumen. Open pit strip mining remains the main extraction method, but two in situ techniques are likely to be used more in future: cyclic steam stimulation (CSS) and steam-assisted gravity drainage (SAGD). These methods inject steam into the formation to heat the bitumen, allowing it to flow and be pumped to the surface.
Gas is used as an energy source to make steam to liquefy the bitumen, enabling its separation, and to generate electricity for mining and treatment. It is also a raw material for hydrogen to break down the long-chain hydrocarbons to yield synthetic crude oil (about 5 kg – 0.6 GJ – is used per barrel). Hydrogen production is by steam reforming of the natural gas.
About 1.05 GJ of natural gas is typically required to produce a barrel of bitumen by in situ methods, and this must then be upgraded to oil. The extraction represents almost 30 cubic metres per barrel of oil (embodying 6 GJ), and in 2006 it accounted for more than 40% of Alberta's natural gas demand.
The Canadian Energy Research Institute (CERI) predicts an increase in gross bitumen production from 1.2 million barrels per day in 2006 to three million barrels per day by 2016 and five million per day by 2024. This means a fourfold increase in gas use being projected by 2016 and sixfold increase by 2024, with the cost exposure increasing dramatically. In fact, Canadian natural gas is inadequate to supply the anticipated expansion in oil sands output and its use has major carbon emissions implications which are creating public concern – almost 20% of the energy in the oil is required to produce it and about 80 kg of carbon dioxide per barrel is released.
From about 2003, various proposals have been made to use nuclear power to produce steam for extraction of the bitumen from these deposits and also to produce electricity for the major infrastructure involved.
Nuclear power could make steam and electricity and use some of the electricity for high-temperature electrolysis for hydrogen production. (Heavy water and oxygen could be valuable by-products of electrolysis.) The steam supply needs to be semi portable as tar sand extraction proceeds, so relatively small reactors which could be moved every decade or so may be needed. One problem related to the provision of steam for mining is that a nuclear plant is a long-life fixture, and mining of tar sands proceeds across the landscape, giving rise to very long steam transmission lines and consequent loss of efficiency.
One proposal from Energy Alberta suggested that a single Candu 6 reactor configured to produce 75% steam and 25% electricity would replace 6 million cubic metres (220 TJ) per day of natural gas and support production of 175-200,000 barrels per day of oil. It would also save the emission of 3.3 million tonnes of carbon dioxide per year. In the region of Energy Alberta's proposal there are leases held by a Shell subsidiary Sure Northern Energy Ltd over limestone containing an estimated 60 billion barrels of heavy bitumen which may recovered using a lot of heat. Shell paid $571 million in 2006 to acquire these oil shale leases, but early development is not expected.
In March 2007, the House of Commons Standing Committee on Natural Resources recommended that "no decision be made on using nuclear energy to extract oil from the tar sands until the repercussions of this process are fully known and understood."1 In its response to the report, the Government supported this view, but pointed out that "it will be industry, working within the framework of provincial laws and regulations, that will determine whether nuclear energy is used to extract oil from the oil sands."2
The committee's report estimated that a reactor of some 600 MWe capacity could supply a processing plant producing 60,000 barrels of synthetic crude oil per day. Hence almost 20 such reactors would be needed to meet the production growth planned to 2015, when Canadian oil output from tar sands is forecast to reach three million barrels per day. Smaller reactors, with capacities of some 100 MWe, could be more suitable for individual projects, given the limitations of supplying steam over more than 25 km.
In March 2008, the US Department of Energy's Idaho National Laboratory (INL) and the Alberta Research Council agreed to jointly study the potential role and implications of nuclear power for extracting and treating Alberta's tar sands – which seem set to become an increasingly important source of oil for the USA. In the initial phase of this collaboration a paper providing background scientific and engineering information aimed at informing industry, public and policy-makers was published.3 The paper was commissioned by Alberta's Nuclear Power Expert Panel, which was established by Alberta's Minister of Energy in May 2008.
The Nuclear Power Expert Panel had itself been requested to prepare a report for the government on the issues associated with the use of nuclear generated electricity in Alberta. Released in March 2009, the Panel's report4 forms the basis of a public consultation to gather views of Albertans on nuclear power in the context of the province’s electricity system.
Meanwhile, CERI published a report5 in February 2009 which says that employing nuclear energy with (so far untested) carbon capture and storage in tar sands extraction and processing could make oil from that source cleaner than conventional oil in respect to its greenhouse gas and other emissions. The CERI report looked at both very large (1600 MWe) and multiple very small (10 MWe) nuclear reactors.
Nuclear Power in Canada
1. The Oil Sands: Toward Sustainable Development, Report of the Standing Committee on Natural Resources, House of Commons Canada (March 2007) [Back]
2. Government Response to the Fourth Report of the Standing Committee on Natural Resources - Oil Sands: Toward Sustainable Development [Back]
3. The Nuclear Energy Option in Alberta submitted by Alberta Research Council and Idaho National Laboratory to the Government of Alberta Nuclear Expert Panel on October 1, 2008 [Back]
4. Report on Nuclear Power and Alberta, Nuclear Power Expert Panel (February 2009) [Back]
5. Green Bitumen: The Role of Nuclear, Gasification and CCS in Alberta’s Oil Sands, Study 119, Canadian Energy Research Institute (February 2009).[Back]
Facebook | Twitter | YouTube | Google+ | Blog | WNA Update | Jobs | Nuclear Portal | Glossary | eShop | Picture Library
© World Nuclear Association. All Rights Reserved 'Promoting the peaceful worldwide use of nuclear power as a sustainable energy resource'