EN13 Nuclear Waste Production
Assessment made on 01 Nov 2008
DPSIR: Driving force
- ENER 013
Policy issue: Is the use and production of energy having a decreasing impact on the environment?
This indicator focuses on the production of nuclear waste: production, reprocessing and storage. In addition attention is paid to aspects related to nuclear power production, including: safety, proliferation, new technology and developments regarding existing and new nuclear plants.
Nuclear power production in the EU:
Within the EU27 a division can be made between countries in which a large fraction (> 20%) of power production is based on nuclear energy and countries in which nuclear power production is absent or contributes very little to total power production. Overall the production of nuclear power has increased by over 20% from 1990 to present. This is mainly due to increased plant availability and increases in net plant efficiencies. The share of nuclear power production in total electricity production slightly declined from approximately 32% in 1990 to 30% in 2005 (see indicator EN27). Anticipated developments in nuclear power production include (Source: World Nuclear Association: http://www.world-nuclear.org/info/inf17.html)): For existing capacity:
- Several countries, like the Netherlands, Belgium and Hungary have decided to extend the life-time of existing NPPs.
- Spain has a program to add 810 MWe (11%) to its nuclear capacity through upgrading its nine reactors by up to 13%. For instance, the Almarez nuclear plant is being boosted by more than 5% at a cost of US$ 50 million. Some 519 MWe of the increase is already in place.
- Finland has boosted the capacity of the Olkiluoto plant by 29% to 1700 MWe. This plant started with two 660 MWe Swedish BWRs commissioned in 1978 and 1980. It is now licensed to operate to 2018. The Loviisa plant, with two VVER-440 (PWR) reactors, has been upgraded by 90 MWe (10%).
- Sweden is upgrading Forsmark plant by 13% (410 MWe) over 2008-10 at a cost of EUR 225 million, and Oskarshamn-3 by 21% to 1450 MWe at a cost of EUR 180 million.
New power plants:
- In Finland (Olikiluoto) and France (Flamanville), the process of building additional capacity, based on new nuclear designs such as the European Pressurised Water Reactor (EPR), is ongoing. Both are planned to start-up in 2012.
- In Romania, the new Cernavoda 2 reactor was finished first power in October 2007. Two further units are expected to commence construction soon.
- Bulgaria is about to start building two 1000 MWe Russian reactors at Belene.
- The three Baltic states agreed in 2006 on the construction of a NPP in Luthuania by 2015. Possibly, Poland will join this project.
The historical series of spent fuel arising is given in Fig. 1. The information presented refers to the quantity of heavy metals in nuclear fuel, which make up approximately 85% of the uranium fuel and 60% - 70% of the aggregation of fuel and fuel casing (fuel assembly).
Arising amounts of spent fuel depend primarily on the amount of power produced, but also to a large extent on the type of reactor, level of fuel enrichment, fuel burnup and net power plant electric efficiency. Arising amounts of spent fuel show a limited decline (approximately 5%) for the period 1990 - 2006, while produced power increased in this period by over 20% (see EN27 for more details). Since very few new nuclear power plants have come online since 1990 and several plants in UK, Lithuania, Germany, Sweden and Bulgaria have been shut down (WNA website) these trends illustrate increased plant availability in the past decades and increases in net plant electric efficiency of approximately 10 percentage points to approximately 32% (WORLD, 2003). They also illustrate the trend in increasing fuel enrichment and fuel burnup and the resulting reduction in spent fuel arising per unit of power. This trend is likely to continue in the future.
Plant closures tend to result in a peak in spent fuel arising as after closure all the fuel present in the reactor core is removed. By, contrast during power production around Â¼ to 1/3 is removed annually as spent fuel. The effects of plant closure on spent fuel production are most pronounced for the UK with decommissioning at Berkley (1989), Trawsfynydd (1993), Hinkley Point (2000) and Bradwell (2002) resulting in the peaks in the graph.
Future development of annually arising spent fuel quantities depends primarily on: political developments and related developments of nuclear power production capacity (new capacity constructed, the type of the new capacity - III and III+ generation or new capacity from upgrading or extending the economic life of existing plants or existing capacity decommissioned),and national policies concerning reprocessing in countries other than France and UK.
The arising amount of spent fuel is not equivalent to the amount of high level waste to be stored, since part of this spent fuel is reprocessed. During reprocessing uranium and the plutonium generated in the reactor are separated from (other) fission products and fuel rod casing for reuse. Uranium is re-enriched (RepU) and reused as nuclear fuel, whilst plutonium is mixed with depleted uranium or tails to create MOX (mixed oxides, ie. nuclear fuel containing both U and Pu oxides), which is also intended as a nuclear fuel. Fission products and fuel rod casings are melted into borosilicate glass and are destined for temporary storage and final disposal. Reprocessing separated uranium is less attractive than using fresh uranium because of the presence of neutron absorbing and gamma radiation emitting uranium isotopes (see e.g. Harvard, 2003 and MIT, 2003). Total reprocessing capacity in France and the UK amounts to 4.100 tonnes of heavy metals per year, and will reduce to 2.600 tonnes due to the closure of Sellafield B 205. In the past decades approximately 72.600 tonnes of heavy metals have been reprocessed (WNA website).
Stored amounts of spent fuel and reprocessing wastes are given in Fig. 3. Storage capacity has not been included because it is relatively easy to create extra (temporary) storage capacity (e.g. spent fuel rack rearranging or canister storage). Available storage capacity therefore has little informative value. Spent nuclear fuel is the most highly radioactive waste. It decays rapidly at first, i.e. after 40 years the level of radioactivity has typically dropped to 1/1000th of the initial value. But it takes around 1000 years to drop to the level of the original uranium ore which was needed to produce that quantity of spent fuel (WNA, 2003). The potential impact of nuclear waste on humans and the environment depends on the level of radioactivity and on the conditions under which the waste is managed. The majority of Member States currently store spent fuel and other high level radioactive wastes in above ground storage facilities and a generally acceptable disposal route for this waste has yet to be identified. However, deep geological disposal in an underground repository is currently favoured as a long-term option by many countries. Geological disposal facilities currently operate in Finland and Sweden. Lower level radioactive wastes are commonly stored in surface disposal sites.
Spent fuel is first stored for several years (usually < 10, but sometimes > 20) in spent fuel ponds 'at reactor' (AR) to allow the reduction of radioactive activity of the fuel to a level at which heat generation and radiation are low enough to allow for handling. After this period fuel is either reprocessed or temporarily stored. Temporary storage, for a period of 50 - 100 years is required, for a further decrease of radioactive activity and heat generation before final storage is possible. Spent fuel in the EU is temporarily stored in both wet and dry storage systems. Facilities are designed to limit radiation to surroundings and to remove the heat from the spent fuel. Storage capacity in Western and Eastern Europe 'away from reactor' (AFR) is approximately 66 ktonnes of heavy metals (HM), of which approximately 53 ktonnes HM is wet storage (IAEA, 2003a). Interim storage facilities range from bunkers able to withstand airplane crashes (such as Habog in the Netherlands) to open air storage in canisters. There is presently no commercial storage facility for permanent storage of HLW (HLW = High level waste). Facilities are being designed and are planned to become operational in 2020 - 2025 in Belgium, Czech Republic, Finland, Netherlands, Spain, Sweden and France.
The risk of insufficiently safe storage of radioactive waste is illustrated by the tritium leakages at the full and closed Centre Stockage de la Manche and Centre de Stockage de l'Aube (both in France) to the surrounding groundwater (http://www.acro.eu.org/ and Burnie, 2007).
The costs of nuclear power production are a subject of intense discussion and estimates range from very low costs of e.g. 2 €ct/kWhe to more than 10 €ct/kWhe (ECN, 2007). Production cost estimates for the intended EPR (European Pressurised Reactor) power plants in France amount to €ct 4.6/kWh (ECN, 2007). Differences between estimated production costs are mainly due to differences in the applied depreciation methodology, depreciation period and interest rates. Costs for insurance may make up 30% of total operational costs. Decommissioning costs are covered by a fund created from sales during the operational lifetime of the plant, in other words are accounted for in the project cash-flow.
Risks are determined by a probabilistic safety assessment (PSA). PSA is conducted at three levels:
- Core melt (PSA 1);
- Release of radioactive materials and radiation from a core melt or other events to the surroundings (PSA 2);
- Occurrence of damage in the surroundings (PSA 3).
Accidents and resulting releases of radioactive material and radioactive radiation are categorized according to the INES scale International Nuclear Event Scale), with INES 7 referring to a major accident. The vast majority of reported events are found to be below Level 3. The Chernobyl accident is regarded in the nuclear power industry as a non-representative exception and is rated as an INES 7 event. Next to this accident one other INES 5 event and three INES 4 events have occurred since nuclear power production became commercially available. The INES 5 event, the Three Mile Island accident, is viewed in the nuclear industry as the evidence that a well designed power plant with a containment structure can absorb even a partial core melt without an impact on the surroundings.
The distribution of nuclear power technology to unstable nations and reprocessing are the main focus of the discussion concerning non-proliferation. Reprocessing is viewed as a sensitive step in the nuclear fuel cycle because of the isolation of plutonium. The isolated plutonium could be used for construction of a primitive nuclear weapon. However, this requires significant technological knowhow and becomes more difficult with higher fuel burnup because the concentration of fissile Pu-239 in the plutonium isolated in reprocessing reduces with higher burnup, while the concentration of poorly fissile and fission hindering Pu-240 increases. The current trend in fuel utilisation is increased burnup, reducing the applicability of the isolated plutonium.
New technology (e.g. 3rd/4th generation):
Technological development in the recent decade has resulted in improved versions of existing LWR reactor designs, such as the EPR, AP-1000, ESBWR and ABWR: the so-called generation III or III+ designs. These have a somewhat higher net electric efficiency compared to current updated generation II reactors (35% - 39% compared to 33% - 35%, (TUD, 2006)) and allow for higher fuel burnup, higher fuel assay and a higher percentage of MOX in the fuel. These specifications mean less fuel is required per kWhe and a larger percentage of spent fuel can be reprocessed. They are also intrinsically safer than updated generation II reactors because of automatic safety features built in to avoid human errors. Development of new reactor designs is coordinated in the so-called Generation IV International Forum (GIF). This is a US-led grouping set up in 2001 and joined by the EU in 2005 which has identified six reactor concepts for further investigation with a view to commercial deployment by 2030. A number of these reactor designs are intrinsically safe. Higher operational temperature will result in higher energy efficiency. Parallel to the Generation IV forum the Pebble Bed Modular Reactor (PBMR) is being developed in South Africa and China. Net efficiency will be 42%, burnup will be at least 90 GWday/tU but may be increased eventually to 200 GWday/tU. At a burnup of 90 GWday/tU the amount of spent fuel per unit of delivered electricity will be 60% smaller than for current Generation II reactors.
For references, please go to http://www.eea.europa.eu/data-and-maps/indicators/en13-nuclear-waste-production-1 or scan the QR code.
PDF generated on 20 Feb 2017, 05:21 PM