Abstract
Uranium is by far the most concentrated available energy source, but with the downside that the physical process of fission generates a surplus of neutrons and radioactive fission products. Objectives exist to ensure the control of reactivity, confinement of radioactive substances and decay heat removal as well as long-term waste management, which are supported by mature methods and stringent safety requirements. Operators and regulators claim that the risk of well-designed and operated power plants with light-water reactors, which dominate the current worldwide fleet of 449 units, is justifiably small. The operating experience has accumulated to more than fifteen thousand years, with typical capacity factor now around 80%. Another 60 facilities are under construction in 15 countries; at the same time, some countries are phasing out nuclear while promoting renewables. New and future generation designs aim at further—in some cases radical—reduction of the risk of core melt accidents and minimize proliferation risks. New designs may also use advanced fuel cycles including thorium that extend and use fuel resources more efficiently and reduce reliance on husbandry of long-lived waste from millennia to centuries.
Most current fuel cycles end with long term storage, relying on the deep geological repository concept, subject to a range of geo-scientific and social uncertainties. Human doses due to potential long-term releases from a repository are calculated to be extremely small, much below natural radioactivity. Although no operating civil disposal facility exists yet, plans are advanced in some countries, especially Finland, where construction has begun in 2016.
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Notes
- 1.
The average number of neutrons that cause new fission events is called effective neutron multiplication, usually denoted by k-effective. If k-effective is equal to 1, the assembly is called critical, and if less than or greater than 1, subcritical and supercritical, respectively. An assembly is called prompt critical (resp. prompt super-critical) if critical (resp. super-critical) without contribution from delayed neutrons. In a supercritical assembly the power increases exponentially with time, with the rate depending on the average time it takes for neutrons to be released in a fission event to cause another fission, and is worse (power excursion) in the case of prompt supercriticality.
- 2.
One Becquerel is the SI unit of radioactivity corresponding to one disintegration per second.
- 3.
Replacement of 1/3 of enriched UO2 fuel by MOX (U, Pu)O2 fuel would avoid net plutonium production. Source: R. Brogli, K. Foskolos, C. Goetzman, W. Kröger, A. Stanculescu, P. Wydler, Fortgeschrittene Nukleare Systeme im Vergleich, PSI Bericht Nr 96–17, Paul Scherrer Institut, Villigen (1996).
- 4.
So-called cross section that qualifies the intrinsic likelihood of a physical event like scattering or absorption/fission when a (neutron) beam strikes a target object (atom), typically denoted sigma with units of area (barn).
- 5.
For example, the cross section of U-238 for thermal fission is almost zero (non-fissile: 11.77 micro barn) but sufficiently high for fast fission (1136 barn).
- 6.
Ratio of fissile atoms created compared to consumed fissile material; LWR have a conversion factor of approximately 0.6.
- 7.
Prototype/commercial fast breeder reactors are operating in Russia (BN-600 (since 1981), BN-800 (since 2015)) or commissioning in India (FBTR) while test and prototype reactors have been operated and shutdown in many countries, including France (Phénix, (1975–2010); Superphénix (1985–98)) and Japan (Monju (1995-dormant)).
- 8.
IAEA Safety Standards, Safety Fundamentals, No. SF-1, IAEA Vienna (2006).
- 9.
States have an obligation of diligence and duty of care and are expected to fulfill their national and international undertakings and obligations. International safety standards provide support for States in meeting their obligations under general principles of international law, such as those relating to environmental protection.
- 10.
IAEA Safety Standards, Specific Design Requirements No.SSR-2/1 (Rev. 1), p.17, IAEA, Vienna (2016).
- 11.
OECD, Comparing Nuclear Accident Risks with Those from Other Energy Sources, OECD Publishing, Paris (2010).
- 12.
IAEA, Basic Safety Principles for Nuclear Power Plants 75-INSAG-3 Rev. 1, INSAG Series No. 12, Vienna (1999).
- 13.
IAEA Safety Standards, Safety of Nuclear Power Plants: Design. SSR-2/1 (Rev. 1), IAEA, Vienna (2016).
- 14.
For the EPR in Finland, a CDF of 2 × 10−6 per reactor year has been estimated and accepted by the Finnish regulator, STUK.
- 15.
While standard second generation LWR are not designed against consequences of the core melt accidents and physical barriers including the confinement structure might be subsequently get lost, most generation three designs cope with such extreme events.
- 16.
Electric Power Research Institute (EPRI), Japanese and Korean Utilities (JURD, KURD), European Utilities (EUR); the EUR documents (www.europeanutilityrequirement.org) formed the basis for the European Pressurized-Water Reactor (EPR, see annexed Fig. 2.11 for Containment Heat Removal System).
- 17.
IAEA, Implementation of Defense in Depth for Next Generation Light Water Reactors, IAEA-TECDOC-986, IAEA, Vienna (1997).
- 18.
IAEA, Guidance for the Evaluation of Innovative Nuclear Reactors and Fuel Cycles Report of Phase 1A of the International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO), IAEA-TECDOC-1362, IAEA, Vienna (2003).
- 19.
The IAEA offers an online tool that presents the up-to-date information online: http://www.iaea.org/PRIS
- 20.
RBMK reactors are an enlarged version of previously existing military reactor developed for production of plutonium; so, their construction required minimal restructuring of existing machinery plants, and RBMKs could use cheap natural uranium, while western analogs require more expensive enriched uranium (Source: Nikolay Dollezhal: At the root the man-made world, Moscow, 2010, fourth edition, p.160–162); new builds are not expected.
- 21.
The load factor is the percentage of time when the reactor is in operation, the rest of the time being used for maintenance, re-fueling, addressing incidents and safety improvements.
- 22.
87 out of 99 nuclear power plants were granted life time extension to 60 years.
- 23.
Andresen, T., Coal Returns to German Utilities Replacing Lost Nuclear, Bloomberg, April 15, 2014 (http://www.bloomberg.com/news/articles/2014-04-14/coal-rises-vampire-like-as-german-utilities-seek-survival)
- 24.
Guerreiro, Cristina, et al. Air Quality in Europe-2016 Report. Publications Office of the European Union, 2016.
- 25.
Such as George Monbiot, the British writer known for his environmental and political activism (https://en.wikipedia.org/wiki/George_Monbiot)
- 26.
Total of 442 (including 40 units in Japan suspended after Fukushima Daiichi nuclear accident) in 31 countries by end of 2015.
- 27.
Hydrogen with one proton but without any neutron is protium (H), with one neutron is deuterium (D), and with two neutrons is tritium (T). A (light) water molecule is made of one atom of oxygen and two atoms of protium (H2O). So-called heavy water is made by replacing the two protium atoms by two deuterium atoms (D2O). Tritiated water contains two atoms of tritium instead of protium (T2O).
- 28.
The first core used highly enriched uranium (U-235 93%) as seed, surrounded by a blanket of natural U-238; the second core was similarly designed but more powerful while the third core kept the same seed- and blanket design now using U-233 as seed and thorium as blanket material (‘thermal breeder reactor’).
- 29.
With 10 active members (Canada, China, EU, France, Japan, South Korea, Russia, Switzerland, USA), three of the 13 signatories are inactive (Brazil, South Africa, UK), www.gen4.org
- 30.
- 31.
The selected Gen IV concepts, their fundamental characteristics and development lines in various as well as related topics, including safety and non-proliferation, are explained in detail in: I.L. Piori (editor) et al., Handbook of Generation IV Nuclear Reactors, Woodhead Publishing Series in Energy, ISBN: 978-0-08-100,162-2 (online), (2016).
- 32.
With an enrichment of 3.5% and average burn-up of 33 GWd/tHM, the fraction of U-235 will be down to almost 1% (Source: [42]); see also Fig 2.3.
- 33.
Measure of toxicity (Sv/TWeh), i.e. health effects after assumed incorporation of a radionuclide including the effects of radioactive daughter products. Radiotoxicity is dependent on radiation quality (type and energy of ionizing radiation) and the bio-kinetics of the radionuclide in the human body.
- 34.
NIREX (Nuclear Industry Radioactive Waste Executive), What is the Nirex Phased Disposal Concept? Harwell, Dicot, 2002.
- 35.
Streffer C., Gethmann C., Kamp G., Kröger W., Rehbinder E., & Renn, O. (2011). Radioactive Waste: Technical and Normative Aspects of its Disposal. Berlin: Springer, 2011 p. 122.
- 36.
An accelerator-driven system provides neutrons to allow for a subcritical reactor to become critical (see Sect. 7.2.5).
- 37.
Pilot-scale continuous testing at Marcoule, France, confirmed the feasibility of adapting the-state-of-technology PUREX process to recover 99% of neptunium (1% losses); for americium and curium, new extractants need to be developed that would allow recovery factors of 99.9%.
- 38.
R. Cashmore et al., Fuel Cycle Stewardship in a Nuclear Renaissance, The Royal Society Science Policy Centre report 10/11, Royal Society, London, Figure 6.
- 39.
Bagla, P., Thorium seen as nuclear’s new frontier, Science 350 (6262), 726–727 (2015).
- 40.
R. Cashmore et al., Fuel Cycle Stewardship in a Nuclear Renaissance, The Royal Society Science Policy Centre report 10/11, Royal Society, London, p. 29 (2011).
- 41.
Fissile material is capable of sustaining a nuclear fission chain. Fertile material itself is not fissionable, but can be converted into fissile material by neutron absorption and subsequent nuclei conversion.
- 42.
E. Mearns, Molten Salt Fast Reactor Technology—An Overview, [Online] http://euanmearns.com/molten-salt-fast-reactor-technology-an-overview/
- 43.
The IAEA considers 8 kg of U-233 enough to construct a nuclear weapon, double compared to Pu-239.
- 44.
Ashley, S.F., G.T. Parks, W.J. Nuttall, C. Boxall and R.W. Grimes, Nuclear energy: Thorium fuel has risks, Nature 492, 31–33 (2012).
- 45.
According to the German Atomic Energy Act, a material is considered radioactive if it contains “one or more radionuclides and whose activity or specific activity in conjunction with nuclear energy or radiation protection cannot be disregarded”. The Act refers to the possibility of clearance or exemption in the case that certain levels of activity or specific activity are not exceeded.
- 46.
Flowers, Sir Brian (September 1976). Nuclear Power and the Environment (6th ed.). London: Royal Commission on Environmental Pollution, ISBN 0 10 166,180 0. Retrieved October 30, 2016.
- 47.
IAEA (International Atomic Energy Agency) (2009a) Geological Repositories. IAEA, Vienna.
- 48.
Notably, low level radioactive waste is also a by-product of use of nuclear fission or technology in other fields such as research and medicine.
- 49.
For typical inventories of safety-relevant radionuclides in canister of spent fuel of nine UO2 fueled BWR, after decay of 40 years, see annexed Table 2.7.
- 50.
See also IAEA waste classification scheme as currently established.
- 51.
See annexed Table 2.7 for inventories of safety-relevant nuclides in a canister of PWR fuel assemblies after 40 years decay.
- 52.
For Germany, the amount of 30,000 m3, or about 17,000 tons, of heavy metal has been estimated for a phase-out according to the Atomic Act 2002.
- 53.
Taking the inventory of 25 plants, operated over 40 years with an annual power production of 10 TWe, as basis, the hypothetical annual dose would be 0.001 mSv; the average value of natural radiation dose adds up to 1 to 2 mSv; the Swiss regulatory body (ENSI) claims to prove less than 0.01 mSv/a for a final repository.
- 54.
R. Cashmore et al., Fuel Cycle Stewardship in a Nuclear Renaissance, The Royal Society Science Policy Centre report 10/11, Royal Society, London, p. 37.
- 55.
- 56.
- 57.
The Joint Convention is the first legal document globally addressing these issues and entering into force in June 2001. It involves 72 parties as of 2016 (http://www.iaea.org/Publications/Documents/Conventions/jointconv_status.pdf) and derives the obligations to the contracting parties from the IAEA fundamentals document “The Principles of Radioactive Waste Management”, 1995.
- 58.
- 59.
Following the compliance check with these obligations the Commission has opened infringement cases against several Member States; two of them have been closed while Romania has been taken to the EU Court of Justice.
- 60.
By Finnish nuclear energy law, such a license has to be approved by the Radiation and Nuclear Safety Authority (STUK), which it did, confirming the license on November 25, 2016.
- 61.
A full presentation of the plan including relevant documents and official statements can be found at https://ensi.ch/en/waste-disposal/deep-geological-repository/sectoral-plan-for-deep-geological-repositories-sgt/
- 62.
President Donald Trump’s administration has proposed reviving the long-stalled Yucca project, but the plan faces bipartisan opposition from the state’s governor and congressional delegation. In May 2018, the U.S. House of Representatives approved a bill to revive the mothballed nuclear waste dump at Nevada’s Yucca Mountain despite opposition from home-state lawmakers.
- 63.
The Royal Society, Fuel cycle stewardship in a nuclear renaissance, The Royal Society Science Policy Centre report 10/11, 2011.
- 64.
NEA, Reversibility and retrievability for the deep disposal of high level radioactive waste and spent fuel. Radioactive Waste Management Committee. OCED Nuclear Energy Agency: Paris. 2011. Oecd-nea.org/rmw/rr/documents/RR_report.pdf
- 65.
Yellow cake is a type of uranium concentrate powder obtained in an intermediate step in the processing of uranium ores. It is a step in the processing of uranium after it has been mined but before fuel fabrication or uranium enrichment.
- 66.
GIF PRPPWG, Evaluation Methodology for Proliferation Resistance and Physical Protection of Generation IV Nuclear Energy Systems, Revision 6, September 15 2011.
- 67.
Under the NPT, all non-nuclear weapons states are required to conclude a comprehensive safeguard agreement with the IAEA. This involves declarations of the quantities and location of all nuclear materials and facilities; their correctness needs to be verified through “measures” by the IAEA (as currently illustrated in the Iran case).
- 68.
The Royal Society, Fuel cycle stewardship in a nuclear renaissance, The Royal Society Science Policy Centre report 10/11, 2011.
- 69.
Highly enriched uraniun-235 (HEU), while the maximum enrichment of fuel for civil/commercial power reactors is limited to 3–5%, or “pure” plutonium-239.
- 70.
Burnup (also known as fuel utilization) quantifies how much energy is extracted from a primary nuclear fuel source. It can be measured as the fraction of fuel atoms that underwent fission in fissions per initial metal atom or as the actual energy released per mass of initial fuel in gigawatt-days/metric ton of heavy metal (GWd/tU).
- 71.
Pu-238 decays relatively rapidly, generating significant amounts of decay heat; Pu-240 could set off the chain reaction prematurely, substantially reducing explosive yield; Pu-241, although fissile, decays to AM-241, which absorbs neutrons and emits intense gamma radiation.
- 72.
The waste form is the key component of the immobilization process, as it determines both waste loading (concentration), which directly impacts cost (due to volume reduction), as well as the chemical durability, which determines environmental risk. See http://www.world-nuclear.org/information-library/nuclear-fuel-cycle/nuclear-wastes/synroc.aspx
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Sornette, D., Kröger, W., Wheatley, S. (2019). Basics of Civilian Nuclear Fission. In: New Ways and Needs for Exploiting Nuclear Energy. Springer, Cham. https://doi.org/10.1007/978-3-319-97652-5_2
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