Uranium economy

from Wikipedia, the free encyclopedia

Under uranium market , all economic activities are understood to be from the processing of uranium ore rich to a usable product on trade in uranium products to its industrial and military use. Because of their great importance for energy supply and for the power and security issues of states, economic activities are largely shaped by political influences.

Uranium mining

Uranium is extracted in open-cast mining , underground or by in-situ leaching , occasionally also as a by-product of other mineral resources (e.g. copper). The world annual production in 2017 was almost 60,000 tons of uranium.

processing

After extraction, the uranium ore is crushed in processing plants , floated and extracted with ion exchangers. The end product is yellowcake , a yellow solid concentrate that contains more than 80% uranium compounds (measured as uranium (V, VI) oxide U 3 O 8 ).

enrichment

Uranium occurs naturally as a mixture of three isotopes : 234 U, 235 U and 238 U. The proportion of the fissile isotope 235 U is only 0.7% and must be increased through enrichment for use in a light water reactor . For enrichment, gaseous uranium hexafluoride (UF 6 ) is separated into a lighter and a heavier fraction either in gas centrifuges or by gas diffusion. The required degree of enrichment depends on the type of reactor and is usually between 2 and 5%. Heavy water reactors such as the CANDU reactor , on the other hand, do not require any enrichment, but process uranium in its natural isotopic composition. An enrichment level of at least 85% is necessary for the construction of effective nuclear weapons .

Manufacture of fuel assemblies

Fuel assemblies are manufactured in fuel assembly factories.

In Germany, there is only one in operation, the Lingen fuel assembly plant ( Lingen in Lower Saxony). It has three production sites (Duisburg, Karlstein (Bavaria) and Lingen).

use

Nowadays, uranium is used almost exclusively for energy production. During the Cold War , a considerable part was processed into nuclear weapons; currently some of the power plant fuel is obtained from the disarmament of these weapons.

Because of its particularly high density , depleted uranium, which is a waste product in the production of nuclear fuel, is used as ballast in aircraft and for armor-piercing ammunition .

World market price

Price of Yellowcake (U 3 O 8 ) on the spot market in $ / lb U 3 O 8 (not adjusted for inflation) since 1987

In addition to commercial market participants, the world market for uranium was and is very much shaped by state actors who made up part of the demand at the time of the Cold War and since the end of the Cold War have acted as sellers as part of limited disarmament. A large part of the market volume is covered by long-term supply contracts, only a very small part of the annual demand is met via the spot market , which is therefore susceptible to price fluctuations. Production stoppages in important mines in the summer of 2007 led to an all-time high of $ 350 / kg uranium, but the uranium price has since fallen back to $ 135 / kg (as of July 2009).

Conventional uranium supplies

Conventional uranium reserves are ore deposits from which uranium can be extracted as the main product or as an important by-product. All uranium producers currently fall into this category. When assessing the available reserves, a distinction is made between secured reserves, presumed resources and speculative resources. During 2008, 778,000 tons of uranium were announced as new reserves and inferred resources by exploration companies.

Secured reserves

From the International Atomic Energy Agency (IAEA) and the OECD Nuclear Energy Agency , the so-called Red Book lists the proven ( reasonably assured resources , RAR ) and recoverable reserves of up to $ 130 / kg for 2007 with 3.3 million. Tonnes stated (for a critical appraisal of the IAEA figures see Energy Watch Group ).

Assumed resources

In addition, the leads Red Book inferred resources ( inferred resources ) amounting to 2.1 million tons of mineable uranium (with production costs of up to $ 130 / kg), the existence of which is likely to direct observation of geological evidence.

Undiscovered resources

Furthermore, in the Red Book the uranium content of as yet undiscovered but expected deposits ( prognosticated resources ) of 2.8 million tons and the uranium content of possibly existing deposits ( speculative resources ) of 4.8 million tons (each recoverable at a maximum of $ 130 / kg). In addition, there are possible deposits of 3.0 million tons of uranium without indication of production costs, for which it is not certain that they can be extracted economically or with a positive overall energy balance.

In contrast to secured reserves and presumed resources, here in the Red Book it is not the recoverable uranium content but the total occurrence that is cited. When interpreting the data, it must therefore be taken into account that - as with other mineral resources - not the entire uranium content of a deposit can be extracted economically: Depending on the type of mining, around 10–30% of the uranium ore remains unused.

Unconventional uranium supplies

The exploitation of unconventional deposits is currently not economical, usually because the uranium concentration in them is too low. This includes, for example, uranium deposits in black shale , phosphate rock or in lignite . The extraction of uranium oxide from radioactive ashes from coal-fired power plants is also being examined and successfully tested. The coal used annually for power generation worldwide contains around 10,000 t of uranium and 25,000 t of thorium , which either end up in the environment or accumulate in power plant ash and filter dust. There have been isolated efforts to extract uranium from power plant ash.

According to the Red Book, there are widely differing estimates for resources from unconventional ores between 7 and 22 million tons, in each case without any indication of extraction costs.

After around 4 billion tons of uranium are dissolved in seawater (content 3.3 µg / l), research is also being carried out into methods for extracting uranium (and other heavy metals) from seawater. So far, however, no process is known that would be economical. (For example, publications by H. Nobukawa give costs of $ 310 / kg (1994) and $ 390 / kg (2001) respectively, while the Red Book cites $ 700 / kg.) A report on research activities from 2012 describes the extraction of uranium from sea water by various adsorbents that have been developed in Japan and the USA.

Range of uranium reserves

It is difficult to estimate the range of known reserves because, unlike fossil fuels, uranium does not have a clearly definable calorific value. The extractable energy per unit weight is strongly dependent on the fuel cycle , the type of reactor used and the core loading strategy. This peculiarity can be seen in the different uranium consumption of individual countries: According to the Red Book, France, which uses partially reprocessed MOX fuel elements , generates almost twice as much electricity per kg natural uranium as in the USA (34 MWh / kg natural -Uranium). At a uranium price of 113 US dollars per pound (2007), this corresponded to a cost share of 0.55 euro cents per kWh. If the calculation of the range is based on the assured and assumed supplies, the annual consumption of 67,000 tons is offset by 5.5 million tons, which leads to a calculated range of around 80 years. However, according to the Red Book , it is assumed that uranium consumption will increase to 94,000–122,000 tons by 2030, so that the range will be reduced accordingly.

Through the use of breeder reactors , reprocessing and utilization of the produced fuels, the energy utilization and thus the range could be increased by a factor of 30–100. However, this technology is difficult to control and expensive and the spread of weapons-grade plutonium is undesirable, so that the numerous research and demonstration facilities have almost all been shut down for good.

Regardless of the question of the scope of the supplies, there is a possibility that supply bottlenecks may arise before the supplies are fully exhausted due to limited annual production volumes. Of the annual consumption of 67,000 tons, only about 40,000 tons are currently covered by ongoing uranium mining, the rest comes from government or commercial stocks, from the processing of tailings or spent fuel elements and from disarmament . It is assumed that these so-called secondary sources will play a smaller role, especially from 2013 onwards, and that uranium mining will therefore be faced with the challenge of significantly increasing the annual output within a relatively short period of time.

Radioactive waste

The generation of energy in nuclear reactors produces radioactive waste that must be permanently sealed off from the biosphere . To date, there is no approved repository for highly radioactive waste anywhere in the world.

In addition to heavy metals , the processing residues also contain most of the natural radioactivity of the ore and must be stored properly.

criticism

Ecological problems

Uranium mining without adequate environmental protection measures regularly leads to large-scale environmental destruction. In the past, carelessly applied tailings have repeatedly led to chemical and radioactive pollution of groundwater, rivers and lakes through seepage water or dam breaches. In several cases, indigenous peoples were exposed to ionizing radiation in dangerous doses and their livelihoods were deprived of them by the contamination of their ancestral ecosystems.

The former mining sites in eastern Germany are an example of the long-term effects of uranium mining. Since 1990, the environmental damage caused in the GDR era has been rehabilitated by Wismut GmbH with a total budget of 6.2 billion euros .

Health risks

Workers in nuclear facilities and in uranium mining as well as their neighbors are exposed to an increased radiation risk even if strict radiation protection regulations are observed . A bigger problem, however, are cases in which either no effective regulations exist or companies ignore them, as is documented for Uranium City , for example .

See also

Individual evidence

  1. ^ Uranium 2018: Resources, Production and Demand (The Red Book), NEA, 2018, page 55 .
  2. ^ Systematic Radiological Assessment of Exemption for Source and Byproduct Materials. (PDF; 3.3 MB). US Nuclear Regulatory Commission, Section 3.17, pp. 531-533.
  3. ↑ University of Oldenburg: Information on uranium ammunition.
  4. ↑ P. Laznicka: Metal Resources Announced in 2008: Do they replenish the mined-out tonnages? SEG Newsletter, April 2009, The Society of Economic Geologists, p. 23.
  5. ↑ a b c d e f g h i OECD Nuclear Energy Agency and International Atomic Energy Agency : Uranium 2007: Resources, Production and Demand . OECD Publishing, 2008, ISBN 978-92-64-04768-6 (English).
  6. ↑ Uranium 2005 ( Memento of June 26, 2008 in the Internet Archive ), background paper of the Energy Watch Group: Uranium Resources and Nuclear Energy. (engl.) .
  7. ↑ Marcela Bilek et al: Life-Cycle Energy Balance and Greenhouse Gas Emissions of Nuclear Energy in Australia . Ed .: Center for Integrated Sustainability Analysis, University of Sydney, Australia. November 3, 2006 ( edu.au [PDF]).
  8. ↑ from World Nuclear News ( memento of the original from March 20, 2009) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. . @1@ 2Template: Webachiv / IABot / www.spartonres.ca
  9. ↑ world-nuclear.org
  10. ↑ atomenergie.ch: Uranium in sea water ( Memento from September 14, 2008 in the Internet Archive ).
  11. ↑ Report of the US Government .
  12. ↑ Hisashi Nobukawa et al: A Barge-Type System for Extracting Uranium from Seawater Using Pump Units . In: Bulletin of the Society of Sea Water Science . tape 55 , no. 3 , 2001, ISSN  0369-4550 , p. 166-174 (Japanese, jst.go.jp ).
  13. ↑ pnnl.gov
  14. ↑ J. Schindler, W. Zittel: Contribution of uranium costs to the electricity generation costs of nuclear power plants. (Pdf) April 25, 2007, accessed March 28, 2011 .
  15. ↑ Daniel Lübbert, Felix Lange: Uranium as nuclear fuel: supplies and range . In: Newsletter WF VIII G . tape 06 , no. 069 . Scientific Services of the German Bundestag, March 27, 2006 ( solarenergie-zuerisee.ch [PDF]).
  16. ↑ Uwe Peters: Radioactivity knows no reserve borders. In: Pogrom. No. 135, Society for Threatened Peoples, Hanover 1987.
  17. ↑ Reinhard Trink: As long as radioactive rivers flow - uranium mining in the Black Hills (South Dakota). In: Pogrom. No. 135, Society for Threatened Peoples, Hanover 1987.
  18. ↑ Renate Domnick: Gold that nobody needs. In: Incomindio's newsletter. No. 78, April 1997.
  19. ↑ Peter Bosshard: Uranium does not fall from Heaven. In: Bern Declaration. Zurich 1990.
  20. ↑ a b Peter H. Eichstaedt: If you poison us - Uranium and Native Americans. Red Crane Books, Santa Fee, 1994, ISBN 1-878610-40-6 .
  21. ^ D. Leupold, M. Paul: The reference project Wismut: Rehabilitation and revitalization of uranium ore mining sites in Saxony and Thuringia. In: Proceedings of the International Mining Symposium Wismut 2007 - Decommissioning and revitalization of mining sites for sustainable regional development. Wismut GmbH, 2007, pp. 21-30.
  22. ↑ Oswald Iten: Uranium City: Dead end for Canada's Indians. In: No mercy for the Indians - struggle for survival from Alaska to Bolivia. Verlag Neue Zürcher Zeitung, Zurich 1992, ISBN 3-85823-353-6 .

literature

  • Peter H. Eichstaedt: If you poison us - Uranium and Native Americans . Red Crane Books, Santa Fee 1994, ISBN 1-878610-40-6 .

Web links