Nuclear power proposed as renewable energy

Although nuclear power is considered a form of low-carbon power,[1][2] its legal inclusion with renewable energy power sources has been a subject of debate and classification. Statutory definitions of renewable energy usually exclude many present nuclear energy technologies, with notable exceptions in the states of Utah,[3] and Arizona in the United States,[4] where only a particular implementation of nuclear fission with "waste"/fuel recycling meets the state's criteria.[5] Dictionary sourced definitions of renewable energy technologies often omit or explicitly exclude mention to every nuclear energy source, with an exception made for the natural nuclear decay heat generated within the Earth/geothermal energy.[6][7]

The most common fuel used in conventional nuclear fission power stations, uranium-235 is "non-renewable" according to the Energy Information Administration, the organization however is silent on the recycled fuel of MOX.[7] Similarly, the National Renewable Energy Laboratory does not mention nuclear power in its "energy basics" definition.[8]

In 1987, the World Commission on Environment and Development (WCED) classified fission reactors that produce more fissile nuclear fuel than they consume (breeder reactors, and if developed, fusion power) among conventional renewable energy sources, such as solar and falling water.[9] The American Petroleum Institute likewise does not consider conventional nuclear fission as renewable, but that breeder reactor nuclear fuel is considered renewable and sustainable, and while conventional fission leads to waste streams that remain a concern for millennia, the waste from efficiently burnt up spent fuel requires storage for no more than a thousand years.[10][11][12] The monitoring and storage of radioactive waste products is also required upon the use of other renewable energy sources, such as geothermal energy.[13]

Definitions of renewable energy

Renewable energy flows involve natural phenomena, which with the exception of tidal power, ultimately derive their energy from the sun (a natural fusion reactor) or from geothermal energy, which is heat derived in greatest part from that which is generated in the earth from the decay of radioactive isotopes, as the International Energy Agency explains:[14]

Renewable energy is derived from natural processes that are replenished constantly. In its various forms, it derives directly from the sun, or from heat generated deep within the earth. Included in the definition is electricity and heat generated from sunlight, wind, oceans, hydropower, biomass, geothermal resources, and biofuels and hydrogen derived from renewable resources.

Renewable energy resources exist over wide geographical areas, in contrast to other energy sources, which are concentrated in a limited number of countries.[14]

In ISO 13602-1:2002, a renewable resource is defined as "a natural resource for which the ratio of the creation of the natural resource to the output of that resource from nature to the technosphere is equal to or greater than one".

Conventional fission, breeder reactors as renewable

Nuclear fission reactors are a natural energy phenomenon, having naturally formed on earth in times past, for example a natural nuclear fission reactor which ran for thousands of years in present-day Oklo Gabon was discovered in the 1970s. It ran for a few hundred thousand years, averaging 100 kW of thermal power during that time.[15][16]

Conventional, human manufactured, nuclear fission power stations largely use uranium, a common metal found in seawater, and in rocks all over the world,[17] as its primary source of fuel. Uranium-235 "burnt" in conventional reactors, without fuel recycling, is a non-renewable resource, and if used at present rates would eventually be exhausted.

A cutaway model of the 2nd most powerful presently operating fast breeder reactor in the world. The (BN-600), at 600 MW of nameplate capacity is equivalent in power output to a natural gas CCGT. It dispatches 560 MW to the Middle Urals power grid. Construction of a second breeder reactor, the BN-800 reactor was completed in 2014.

This is also somewhat similar to the situation with a commonly classified renewable source, geothermal energy, a form of energy derived from the natural nuclear decay of the large, but nonetheless finite supply of uranium, thorium and potassium-40 present within the Earth's crust, and due to the nuclear decay process, this renewable energy source will also eventually run out of fuel. As too will the Sun, and be exhausted.[18][19]

Nuclear fission involving breeder reactors, a reactor which breeds more fissile fuel than they consume and thereby has a breeding ratio for fissile fuel higher than 1 thus has a stronger case for being considered a renewable resource than conventional fission reactors. Breeder reactors would constantly replenish the available supply of nuclear fuel by converting fertile materials, such as uranium-238 and thorium, into fissile isotopes of plutonium or uranium-233, respectively. Fertile materials are also nonrenewable, but their supply on Earth is extremely large, with a supply timeline greater than geothermal energy. In a closed nuclear fuel cycle utilizing breeder reactors, nuclear fuel could therefore be considered renewable. In 1983, physicist Bernard Cohen claimed that fast breeder reactors, fueled exclusively by natural uranium extracted from seawater, could supply energy at least as long as the sun's expected remaining lifespan of five billion years.[20] This was based on calculations involving the geological cycles of erosion, subduction, and uplift, leading to humans consuming half of the total uranium in the Earth’s crust at an annual usage rate of 6500 tonne/yr, which was enough to produce approximately 10 times the world's 1983 electricity consumption, and would reduce the concentration of uranium in the seas by 25%, resulting in an increase in the price of uranium of less than 25%.[20][21]

Proportions of the isotopes, U-238 (blue) and U-235 (red) found in natural uranium, versus grades that are enriched. light water reactors and the natural uranium capable CANDU reactors, are primarily powered only by the U-235 component, failing to extract much energy from U-238. While by contrast uranium breeder reactors mostly use U-238/the primary constituent of natural uranium as their fuel.[22]

Advancements at Oak Ridge National Laboratory and the University of Alabama, as published in a 2012 issue of the American Chemical Society, towards the extraction of uranium from seawater have focused on increasing the biodegradability of the process and reducing the projected cost of the metal if it was extracted from the sea on an industrial scale. The researchers' improvements include using electrospun Shrimp shell Chitin mats that are more effective at absorbing uranium when compared to the prior record setting Japanese method of using plastic amidoxime nets.[23][24][25][26][27][28] As of 2013 only a few kilograms (picture available) of uranium have been extracted from the ocean in pilot programs and it is also believed that the uranium extracted on an industrial scale from the seawater would constantly be replenished from uranium leached from the ocean floor, maintaining the seawater concentration at a stable level.[29] In 2014, with the advances made in the efficiency of seawater uranium extraction, a paper in the journal of Marine Science & Engineering suggests that with, light water reactors as its target, the process would be economically competitive if implemented on a large scale.[30] In 2016 the global effort in the field of research was the subject of a special issue in the journal of Industrial & Engineering Chemistry Research.[31][32]

In 1987, the World Commission on Environment and Development(WCED), an organization independent from, but created by, the United Nations, published Our Common Future, in which a particular subset of presently operating nuclear fission technologies, and nuclear fusion were both classified as renewable. That is, fission reactors that produce more fissile fuel than they consume - breeder reactors, and when it is developed, fusion power, are both classified within the same category as conventional renewable energy sources, such as solar and falling water.[9]

Presently, as of 2014, only 2 breeder reactors are producing industrial quantities of electricity, the BN-600 and BN-800. The retired French Phénix reactor also demonstrated a greater than one breeding ratio and operated for ~30 years, producing power when Our Common Future was published in 1987. While human sustained nuclear fusion is intended to be proven in the International thermonuclear experimental reactor between 2020 and 2030, and there are also efforts to create a pulsed fusion power reactor based on the inertial confinement principle (see more Inertial fusion power plant).

Fuel supply

Estimates of Available Uranium-235, an isotope required for the present world fleet of light water reactors, that is, not the uranium-238 feedstock needed for some breeder reactor designs, one of which was discussed above. Available U-235 estimates depend on what ore resources are included in the simple extrapolations. The squares represent relative sizes of different estimates, whereas the numbers at the lower edge give an estimate on how long the given resource would last at present U-235 consumption rates, a consumption rate based upon the unrealistic assumption that old LWR generation II reactors will still be operating after their lifetimes are up, 30 years from now, and that no Generation III reactors or generation IV reactors replace these less efficient reactors.
██ Reserves in current mines[33]
██ Known economic reserves, a figure that has increased from 80 to over 100 years after this estimate was made in 2005.[34]
██ Conventional undiscovered resources[35]
██ Total ore resources at 2004 prices[33]
██ Unconventional resources (at least 4 billion tons, could last for millennia)[35]

The world's measured resources of uranium-235 in 2013 was estimated to be enough to last over 120 years at current (2013) consumption rates.[34]

30,000 to 60,000 years is one estimated supply lifespan of fission-based conventional/light water reactor reserves if it is possible to extract all the uranium from seawater, assuming current world energy consumption.[36] Alternatively this is about 6,500 years with a potential nuclear reactor fleet of 3,000 GW, a quantity of electricity six to seven times higher than the current world civil nuclear power capacity.[37]

The OECD have also calculated that with fast breeder reactors such as the BN-800 and conceptual Integral Fast Reactor, which has a closed nuclear fuel cycle with a burn up of, and recycling of, all the uranium, plutonium and minor actinides; actinides which presently make up the most hazardous substances in nuclear waste, there is 160,000 years worth of natural uranium in total conventional land resources and phosphate ore.[38]

Thorium, an often overlooked alternative to fertile U-238 in breeder reactors, is several times (about 3 to 4)[39][40][41][42] more abundant in the earth crust than natural uranium-238. The average concentration or occurrence of thorium in seawater however is over 1000 times lower, in the range of nanograms per liter compared to uranium which is about 3 micrograms per liter,[39][43][44][45] 3 mg (milligrams) per cubic meter/ton of water.[29]

In 1983, physicist Bernard Cohen calculated that fast breeder reactors, fueled exclusively by natural uranium extracted from seawater, could supply energy at least as long as the sun's expected remaining lifespan of five billion years.[20] This was based on calculations involving the geological cycles of erosion, subduction, and uplift, leading to humans consuming half of the total uranium in the Earth’s crust at an annual usage rate of 6500 tonne/yr, which was enough to produce approximately 10 times the world's 1983 electricity consumption, and would reduce the concentration of uranium in the seas by 25%, resulting in an increase in the price of uranium of less than 25%.[20][21]

Fusion fuel supply

If it is developed, Fusion power would provide more energy for a given weight of fuel than any fuel-consuming energy source currently in use,[46] and the fuel itself (primarily deuterium) exists abundantly in the Earth's ocean: about 1 in 6500 hydrogen (H) atoms in seawater (H2O) is deuterium in the form of (semi-heavy water).[47] Although this may seem a low proportion (about 0.015%), because nuclear fusion reactions are so much more energetic than chemical combustion and seawater is easier to access and more plentiful than fossil fuels, fusion could potentially supply the world's energy needs for millions of years.[48][49]

In the deuterium + lithium fusion fuel cycle, 60 million years is the estimated supply lifespan of this fusion power, if it is possible to extract all the lithium from seawater, assuming current (2004) world energy consumption.[50] While in the second easiest fusion power fuel cycle, the deuterium + deuterium burn, assuming all of the deuterium in seawater was extracted and used, there is an estimated 150 billion years of fuel, with this again, assuming current (2004) world energy consumption.[50]

Legislation in the United States

Inclusion under the "renewable energy" classification as well as the low-carbon classification could render nuclear power projects eligible for development aid under more jurisdictions. Thus a key issue regarding this classification of nuclear power is inclusion in Renewable portfolio standard (RES).

A bill proposed in the South Carolina Legislature in 2007-2008 aimed to classify nuclear power as renewable energy. The bill listed as renewable energy: solar photovoltaic energy, solar thermal energy, wind power, hydroelectric, geothermal energy, tidal energy, recycling, hydrogen fuel derived from renewable resources, biomass energy, nuclear energy, and landfill gas.[51]

In 2009 the Utah state passed the bill ECONOMIC DEVELOPMENT INCENTIVES FOR ALTERNATIVE ENERGY PROJECTS including incentives for renewable energy projects. It includes a direct reference to nuclear power: "Renewable energy" means the energy generation as defined in Subsection 10-19-102 (11) and includes generation powered by nuclear fuel. The bill passed the house with 72 yeas, 0 nays, and 3 absent, passed the senate with 24 yeas, 1 nay, and 4 absent, then received the governor's signature.[3]

In 2010 the Arizona Legislature included nuclear power in a proposed bill for electric utility renewable energy standards. The bill defined "renewable energy" as energy that is renewable and non-carbon emitting. It listed solar, wind, geothermal, biomass, hydroelectric, agricultural waste, landfill gas and nuclear sources.[4]

In 2015 the Arizona bill specified that "Nuclear energy from sources fueled by uranium fuel rods that include 80 percent or more of recycled nuclear fuel and natural thorium reactor resources under development" are renewable.[52]

Supporters

Nuclear energy has been referred to as "renewable" by the politicians George W. Bush,[53] Charlie Crist,[54] and David Sainsbury.[55][56] In 2006, speaking on the topics of economic growth and getting oil from parts of the world where "they simply don’t like us", US President Bush said: "Nuclear power is safe and nuclear power is clean and nuclear power is renewable".[53]

See also

References

  1. ↑ "CARBON FOOTPRINT OF ELECTRICITY GENERATION" (PDF). London: Parliamentary Office of Science and Technology. October 2006. Retrieved 26 May 2010.
  2. ↑ See "Life-cycle greenhouse-gas emissions of energy sources"
  3. 1 2 Utah House Bill 430, Session 198
  4. 1 2 Arizona House Bill 2701. By 2025 15% of electricity used by retail customers would have to come from the listed sources.
  5. ↑ S. Smith, "Introduced Bill: Renewable Energy; Definition," Arizona State Senate, SB 1134, January 2015. nuclear energy from sources fueled by uranium fuel rods that include 80 percent or more of recycled nuclear fuel and natural thorium reactor resources under development
  6. ↑ "Renewable energy: Definitions from Dictionary.com". Dictionary.com website. Lexico Publishing Group, LLC. Retrieved 2007-08-25.
  7. 1 2 "Renewable and Alternative Fuels Basics 101". Energy Information Administration. Retrieved 2007-12-17.
  8. ↑ "Renewable Energy Basics". National Renewable Energy Laboratory. Retrieved 2007-12-17.
  9. 1 2 Brundtland, Gro Harlem (20 March 1987). "Chapter 7: Energy: Choices for Environment and Development". Our Common Future: Report of the World Commission on Environment and Development. Oslo. Retrieved 27 March 2013. Today's primary sources of energy are mainly non-renewable: natural gas, oil, coal, peat, and conventional nuclear power. There are also renewable sources, including wood, plants, dung, falling water, geothermal sources, solar, tidal, wind, and wave energy, as well as human and animal muscle-power. Nuclear reactors that produce their own fuel ('breeders') and eventually fusion reactors are also in this category
  10. ↑ American Petroleum Institute. "Key Characteristics of Nonrenewable Resources". Retrieved 2010-02-21.
  11. ↑ pg 15 see SV/g chart, without "TRU" or trans-uranics being present, the radioactivity of the waste decays to levels similar to the original uranium ore in about 300–400 years
  12. ↑ MIT spent fuel radioactivity comparison, table 4.3
  13. ↑ http://www.epa.gov/radiation/tenorm/geothermal.html Geothermal Energy Production Waste.
  14. 1 2 IEA Renewable Energy Working Party (2002). Renewable Energy... into the mainstream, p. 9.
  15. ↑ Meshik, A. P. (November 2005). "The Workings of an Ancient Nuclear Reactor". Scientific American.
  16. ↑ Gauthier-Lafaye, F.; Holliger, P.; Blanc, P.-L. (1996). "Natural fission reactors in the Franceville Basin, Gabon: a review of the conditions and results of a "critical event" in a geologic system". Geochimica et Cosmochimica Acta. 60 (25): 4831–4852. Bibcode:1996GeCoA..60.4831G. doi:10.1016/S0016-7037(96)00245-1.
  17. ↑ http://www.eia.gov/energyexplained/index.cfm?page=nuclear_home
  18. ↑ The end of the Sun
  19. ↑ Earth Won't Die as Soon as Thought
  20. 1 2 3 4 Cohen, Bernard L. (January 1983). "Breeder reactors: A renewable energy source" (PDF). American Journal of Physics. 51 (1): 75–76. Bibcode:1983AmJPh..51...75C. doi:10.1119/1.13440. Retrieved 2007-08-03.
  21. 1 2 McCarthy, John (1996-02-12). "Facts from Cohen and others". Progress and its Sustainability. Stanford. Retrieved 2007-08-03.
  22. ↑ Cohen, Fuel of the Future, Chapter 13
  23. ↑ "Nanofibers Extract Uranium from Seawater Hidden within the oceans, scientists have found a possible way to power nuclear reactors long after uranium mines dry up.".
  24. ↑ "abstracts from papers for the ACS Extraction of Uranium from Seawater conference".
  25. ↑ "Advances in decades-old dream of mining seawater for uranium".
  26. ↑ "Shrimp 30,000 volts help UA start up land 1.5 million for uranium extraction. 2014".
  27. ↑ Details of the Japanese experiments with Amidoxime circa 2008, Archive.org
  28. ↑ Confirming Cost Estimations of Uranium Collection from Seawater, from Braid type Adsorbent. 2006
  29. 1 2 "The current state of promising research into extraction of uranium from seawater — Utilization of Japan's plentiful seas".
  30. ↑ Development of a Kelp-Type Structure Module in a Coastal Ocean Model to Assess the Hydrodynamic Impact of Seawater Uranium Extraction Technology. Wang et. al. J. Mar. Sci. Eng. 2014, 2(1), 81-92; doi:10.3390/jmse2010081
  31. ↑ Uranium Seawater Extraction Makes Nuclear Power Completely Renewable. Forbes. James Conca. July 2016
  32. ↑ April 20, 2016 Volume 55, Issue 15 Pages 4101-4362 In this issue:Uranium in Seawater
  33. 1 2 Herring, J. S. (2004). "Uranium and thorium resource assessment". In Cleveland, C. J. Encyclopedia of Energy. Boston University. pp. 279–298. doi:10.1016/B0-12-176480-X/00292-8. ISBN 0-12-176480-X.
  34. 1 2 NEA, IAEA (2014). Uranium 2014 – Resources, Production and Demand (PDF). OECD Publishing. doi:10.1787/uranium-2014-en. ISBN 978-92-64-22351-6.
  35. 1 2 Price, R.; Blaise, J. R. (2002). "Nuclear Fuel Resources: Enough to Last?" (PDF). NEA News. 20 (2): 10–13.
  36. ↑ Fetter, Steve (March 2006). "How long will the world's uranium supplies last?".
  37. ↑ "Presidential Committee recommends research on uranium recovery from seawater" (link to PDF). The President's Committee Of Advisors On Science And Technology. August 2, 1999. Retrieved 2008-05-10. ... this resource ... could support for 6,500 years 3,000 GW of nuclear capacity ... Research on a process being developed in Japan suggests that it might be feasible to recover uranium from seawater at a cost of $120 per lb of U3O8.[40] Although this is more than double the current uranium price, it would contribute just 0.5¢ per kWh to the cost of electricity for a next-generation reactor operated on a once-through fuel cycle—...
  38. ↑ "figure 4.10 pg 271" (PDF).
  39. 1 2 Isotopes of the Earth's Hydrosphere By V.I. Ferronsky, V.A. Polyakov, pg 399.
  40. ↑ "Radioactivity in Nature, see table".
  41. ↑ Lasers and Nuclei: Applications of Ultrahigh Intensity Lasers in Nuclear Science edited by Heinrich Schwoerer, Joseph Magill, Burgard Beleites, pg 182.
  42. ↑ Wickleder 2006, p. 53.
  43. ↑ "Toxicological profile for thorium - Agency for Toxic Substances and Disease Registry U.S. Public Health Service 1990, pg 76 "world average concentration in seawater is 0.05 μg/L (Harmsen and De Haan 1980)"" (PDF).
  44. ↑ "Determination of thorium concentration in seawater by neutron activation analysis C. A. Huh , M. P. Bacon Anal. Chem., 1985, 57 (11), pp 2138–2142 DOI: 10.1021/ac00288a030".
  45. ↑ "T H E P E R I O D I C T A B L E with SEAWATER ADDITIONs".
  46. ↑ Robert F. Heeter; et al. "Conventional Fusion FAQ Section 2/11 (Energy) Part 2/5 (Environmental)".
  47. ↑ Dr. Frank J. Stadermann. "Relative Abundances of Stable Isotopes". Laboratory for Space Sciences, Washington University in St. Louis. Archived from the original on 2011-07-20.
  48. ↑ J. Ongena and G. Van Oost. "Energy for Future Centuries" (PDF). Laboratorium voor Plasmafysica– Laboratoire de Physique des Plasmas Koninklijke Militaire School– Ecole Royale Militaire; Laboratorium voor Natuurkunde, Universiteit Gent. pp. Section III.B. and Table VI.
  49. ↑ EPS Executive Committee. "The importance of European fusion energy research". The European Physical Society. Archived from the original on 2008-10-08.
  50. 1 2 Ongena, J; G. Van Oost. "Energy for future centuries - Will fusion be an inexhaustible, safe and clean energy source?" (PDF). Fusion Science and Technology. 2004. 45 (2T): 3–14.
  51. ↑ South Carolina State House, 117th Session, S. 360
  52. ↑ S. Smith, "Introduced Bill: Renewable Energy; Definition," Arizona State Senate, SB 1134, January 2015. nuclear energy from sources fueled by uranium fuel rods that include 80 percent or more of recycled nuclear fuel and natural thorium reactor resources under development
  53. 1 2 "Bush: U.S. must end dependence on foreign oil". MSNBC. Associated Press. September 4, 2006. Archived from the original on 2007-11-05. Retrieved 2007-03-11.
  54. ↑ "Governor Crist Opens Florida Summit on Global Climate Change". flgov.com. 2007-07-12. Retrieved 2007-08-03.
  55. ↑ Minister declares nuclear 'renewable' — UK Times
  56. ↑ "UK To Redefine Nuclear Energy As Renewable?". WISE/NIRS Nuclear Monitor. 2005-11-04. Retrieved 2007-08-03.
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