A new study released today shows European leaders are being misled over the safety of underground nuclear waste disposal which could poison ground waters for centuries. The European Commission is due to publish a draft nuclear waste directive this autumn. The new report, 'Rock Solid? A scientific review of geological disposal of high-level radioactive waste' by Helen Wallace for Greenpeace International examines the current state of scientific evidence regarding the geological disposal of spent nuclear fuel and other high-level and long-lived radioactive wastes.
Deep disposal has dominated the research into the management of highly radioactive nuclear waste for over 30 years and is expected to be central to the directive. However, the European Commission has been misinformed of the dangers of deep disposal by its most critical advisors, the Joint Research Centre (JRC) and European Implementing Geological Disposal Technology Platform (IGD-TP). Both claim that a scientific consensus has been reached and construction should proceed. However, there is evidence to suggest that this is biased and deep geological storage projects could have serious problems that have not been identified because of lack of resources and funding for independent scrutiny.
The European Atomic Energy Community (Euratom), which was founded in 1957 to promote the use of nuclear power in Europe, has been financing research in the area of geological disposal of high level radioactive waste for more than three decades and has provided considerable support to national research and development programs.
Worldwide, thirteen countries are actively pursuing long-term waste management programs for high-level radioactive wastes resulting from nuclear electricity generation, but no country has yet completed an operational geological disposal facility for such wastes.
The 2009 Euratom-funded Vision Document of the European Implementing Geological Disposal of Radioactive Waste Technology Platform (IGD-TP) states that “a growing consensus exists” that deep disposal is the most appropriate solution to disposing of spent nuclear fuel, high-level waste and other long-lived radioactive wastes, and that it is time to proceed to licensing the construction and operation of deep geological repositories for radioactive waste disposal. This conclusion is supported by the 2009 report of the European Commission’s (EC’s) Joint Research Centre (JRC), which states that “our scientific understanding of the processes relevant for geological disposal has developed well enough to proceed with step-wise implementation”.
The IGD-TP Vision Document has been prepared by an Interim Executive Group with members from the nuclear waste management organizations SKB (Sweden), Posiva (Finland) and Andra (France) and the German Federal Ministry of Economics and Technology (BMWi). It adopts the vision that by 2025 the first geological disposal facilities for spent nuclear fuel, high-level waste and other long-lived radioactive waste will be operating safely in Europe. The Director of Energy (Euratom) for the European Commission’s Directorate-General for Research states in the Foreword:
These will not only be the first such facilities in Europe but also the first in the world. I am convinced that through this initiative, safe and responsible practices for the long-term management of hazardous radioactive waste can be disseminated to other Member States and even 3rd countries, thereby ensuring the greatest possible protection of all citizens and the environment both now and in the future.
The IGD-TP states that inherent in “all the successful outcomes to date in European nuclear waste management programs” are judgments that safe geological disposal of spent nuclear fuel, high level waste, and other long-lived radioactive waste is achievable: “In this context, the future RD&D [Research, Development and Demonstration] issues to be pursued, including their associated uncertainties, are not judged to bring the feasibility of disposal into question.” This statement reflects the view expressed by the Radioactive Waste Management Committee (RWMC) of the OECD’s Nuclear Energy Agency (NEA) that “geological disposal is technically feasible” and that a “geological disposal system provides a unique level and duration of protection for high activity, long-lived radioactive waste”.
However, the OECD/NEA position is merely a collective statement, based on the views of the RWMC, not an analysis of the existing scientific evidence. Similarly, the IGD-TP report relies on a road map towards radioactive waste management developed by the European Nuclear Energy Forum, and includes no references to papers in scientific journals. The EC’s JRC report is largely a description of ongoing research projects; it cites only three papers published in academic journals (one of which dates from 1999) plus lists of background reports, largely published by the NEA and International Atomic Energy Agency (IAEA), and a few conference papers. The report makes no obvious links between these summaries of research activity and its conclusion that Europe is ready to proceed to implementation of deep geological disposal. In a rare example of a referenced claim, the JRC’s statement that corrosion of steel (and the generation of hydrogen gas by this process) will not compromise the safety of a repository is based solely on an unpublished note of a panel discussion held in Brussels in 2007. Further, the report falsely claims that repository programs in Germany and the UK have “(temporarily) foundered mainly for reasons of public acceptance”, rather than because of safety issues.
In contrast, the present report is based on a literature review of research on deep disposal published in peer-reviewed scientific journals. It provides an overview of the status of research and scientific evidence regarding the long-term underground storage of highly radioactive wastes, and asks whether this evidence supports the view that such wastes can be disposed of safely underground. It finds that significant scientific uncertainties remain and it accordingly questions whether strong conclusions in favor of deep disposal can be drawn until all the relevant issues have been addressed.
This review identifies a number of phenomena that could compromise the containment barriers, potentially leading to significant releases of radioactivity:
* Copper or steel canisters and overpacks containing spent nuclear fuel or high-level radioactive wastes could corrode more quickly than expected.
* The effects of intense heat generated by radioactive decay, and of chemical and physical disturbance due to corrosion, gas generation and biomineralisation, could impair the ability of backfill material to trap some radionuclides.
* Build-up of gas pressure in the repository, as a result of the corrosion of metals and/or the degradation of organic material, could damage the barriers and force fast routes for radionuclide escape through crystalline rock fractures or clay rock pores.
* Poorly understood chemical effects, such as the formation of colloids, could speed up the transport of some of the more radiotoxic elements such as plutonium.
* Unidentified fractures and faults, or poor understanding of how water and gas will flow through fractures and faults, could lead to the release of radionuclides in groundwater much faster than expected.
* Excavation of the repository will damage adjacent zones of rock and could thereby create fast routes for radionuclide escape.
* Future generations, seeking underground resources or storage facilities, might accidentally dig a shaft into the rock around the repository or a well into contaminated groundwater above it.
* Future glaciations could cause faulting of the rock, rupture of containers and penetration of surface waters or permafrost to the repository depth, leading to failure of the barriers and faster dissolution of the waste.
* Earthquakes could damage containers, backfill and the rock.
Although computer models of such phenomena have undoubtedly become more sophisticated, fundamental difficulties remain in predicting the relevant complex, coupled processes (including the effects of heat, mechanical deformation, microbes and coupled gas and water flow through fractured crystalline rocks or clay) over the long timescales necessary. In particular, more advanced understanding and modelling of chemical reactions is essential in order to evaluate the geochemical suitability of repository designs and sites.
The suitability of copper, steel and bentonite as materials for canisters, overpacks and backfill also needs to be reassessed in the light of developing understanding of corrosion mechanisms and the effects of heat and radiation.
Unless and until such difficulties can be resolved, a number of scenarios exist in which a significant release of radioactivity from a deep repository could occur, with serious implications for the health and safety of future generations. In this light, the existence in a number of countries of ‘road maps’ for the implementation of deep disposal, and the rejection of other options, do not automatically mean that deep disposal of highly radioactive wastes is safe.
At present, the following issues remain unresolved and have implications for policy development:
* the high likelihood of interpretative bias in the safety assessment process because of the lack of validation of models, the role of commercial interests and the pressure to implement existing road maps despite important gaps in knowledge. Lack of (funding for) independent scrutiny of data and assumptions can strongly influence the safety case
* lack of a clearly defined inventory of radioactive wastes, as a result of uncertainty about the quantities of additional waste that will be produced in new reactors, increasing radioactivity of waste due to the use of higher burn-up fuels, and ambiguous definitions of what is considered as waste
* the question of whether site selection and characterization processes can actually identify a large enough volume of rock with sufficiently favorable characteristics to contain the expected volume of wastes likely to be generated in a given country
* tension between the economic benefits offered to host communities and long-term repository safety, leading to a danger that concerns about safety and impacts on future generations may be sidelined by the prospect of economic incentives, new infrastructure or jobs. There is additional tension between endorsement of deep disposal as a potentially ‘least bad’ option for existing wastes, and nuclear industry claims that deep repositories provide a safe solution to waste disposal and so help to justify the construction of new reactors
* potential for significant radiological releases through a variety of mechanisms, involving the release of radioactive gas and/or water due to the failure of the near-field or far-field barriers, or both
* significant challenges in demonstrating the validity and predictive value of complex computer models over long timescales
* risk of significant escalation in repository costs.
Source: The report 'Rock Solid? A scientific review of geological disposal of high-level radioactive waste', written by Helen Wallace for Greenpeace International is available at: http://www.greenpeace.org/eu-unit/press-centre/reports/rock-solid-a-scie...
Contact: Greenpeace EU Unit, Jan Haverkamp