[] TL: DEEP CRISIS. BRITAIN'S NUCLEAR WASTE: WHO'S BURYING WHO? SO: Greenpeace UK (GP) DT: 1993 Keywords: nuclear power waste disposal uk europe problems risks landfills / No one can put their hand on their heart and say that any method of dealing with nuclear waste will, in the long term, be satisfactory. There are flaws in every system. But the idea of digging a very deep hole and burying the waste in a vast underground chamber is flawed on so many levels it must be opposed. The deep dump is a last resort for the nuclear industry, which is trying to foist it on a community which already lives under the shadow of radioactivity. The nuclear industry offers no guarantee that the geology of the Sellafield area is suitable, let alone ideal, for the project they have in mind. The industry freely admit that all the human made barriers of the repository will fail in time. But they can offer no guarantees that the surrounding rock will contain the radioactivity released from the waste, and prevent it from contaminating the environment. They offer no guarantees that if anything goes wrong, they will be able to put it right. The community which has to live with the deep repository for nuclear waste is a community condemned for the future. Some of the radioactive waste will remain dangerous for up to a quarter of a million years. We ask the question: 'Who is burying who?'. INTRODUCTION UK Nirex Ltd (Nirex), the nuclear industry's waste disposal arm, are now almost certain to announce later this year the selection of Sellafield in Cumbria as their favoured site for the deep disposal of low and intermediate level radioactive waste. This decision will be based on the results of very limited geological investigations at both Sellafield and Dounreay in Caithness. This booklet is a summary of a longer report entitled 'Taking the Lid Off the Nuclear Dustbin', written for Greenpeace by consulting geologist Phil Richardson. The full report is a geological critique of Nirex's endeavours at both Sellafield and Dounreay. By looking specifically at the two sites Nirex have been investigating, Richardson confirms the conclusions of his earlier report 'Exposing the Faults' that 'the deep disposal option is not proven to be a safe and reliable method of immobilising and isolating nuclear waste from the environment'. Nirex claim there is an international consensus in favour of the deep disposal of radioactive waste, but a closer examination of this so-called consensus reveals widespread uncertainties. Even when a repository has been developed, such as at Forsmark in Sweden, problems have occurred. A considerable amount of uncertainty still surrounds the science behind deep disposal. Nirex will have to use highly complex computer programmes in order to model the natural world. This task has been compared to weather forecasting for the next hundred centuries or so, and we all know how accurate weather forecasting is. Another major uncertainty is the gas which will be generated by the waste itself in the repository. Nirex have to find a way of venting the gases, without providing a pathway for radioactive substances. In short Nirex can offer no guarantees for the safe and effective containment of radioactive waste. In the face of many unknowns, dumping radioactive waste is foolhardy and irresponsible. Taken together, Richardson's two reports confirm the environmentalists' case for above ground storage of radioactive waste, at the site where it is produced, so that it can be monitored and retrieved, and repackaged if problems arise. The rocks beneath Sellafield targeted as the repository host have a large number of faults, and it will never be possible to identify them all. Consequently it will be impossible to understand accurately how ground water circulates, nor predict how radioactive substances will move away from the repository. A public inquiry is due to be held in 1993, but little or no discussion of the overall safety case is proposed. It is therefore perfectly reasonable to ask where the real science is behind a decision based so clearly on political expediency. Although this summary concentrates on Sellafield, this should not be taken to mean that Dounreay will be reprieved. If Nirex are successful in building a repository at Sellafield, it will have a life of only 50 years, and there is always a chance Nirex may decide Sellafield is unsuitable once more detailed investigations have been carried out. Even more worrying, the Government have refused to rule out the possibility of Dounreay being used as a dump site for high-level radioactive waste. Peter Roche Greenpeace, July 1991 SUMMARY OF 'TAKING THE LID OFF THE NUCLEAR DUSTBIN' BACKGROUND In 1980, the Institute of Geological Sciences (now British Geological Survey--BGS) carried out a survey of all existing nuclear installations in the UK with a view to assessing their potential as waste repository sites. Sellafield, the British Nuclear Fuels Ltd (BNFL) installation in Cumbria, was examined, but rejected as unsuitable. Despite this, in March 1989, UK Nirex Ltd (Nirex) announced that following extensive studies, Sellafield and the United Kingdom Atomic Energy Authority (UKAEA) site at Dounreay in Caithness, had been chosen as potential sites for the first UK deep repository for low and intermediate level nuclear waste (LLW & ILW). The selection of these two sites followed the abandonment by Nirex in May 1987 of four potential sites for the shallow burial of LLW. The communities affected had demonstrated their intense hostility to the proposals throughout the mid-1980s. Both Sellafield and Dounreay are large nuclear complexes whose communities are economically dependent on the nuclear industry, and whose opposition to a deep nuclear waste dump was expected to be less vociferous. However, in November 1989 Caithness District Council organised a referendum on Nirex's plans. 74% of voters opposed plans for a repository at Dounreay. Highland Regional Council also launched a campaign against the proposals. By June 1991 Nirex were making no secret of the fact that Sellafield would almost certainly be chosen as their preferred site. THE SEARCH FOR A DUMP SITE Following the rejection of Sellafield by the 1980 Institute of Geological Sciences (IGS) survey of nuclear sites, a geological survey of the entire British Isles and surrounding coastal waters was carried out by BGS. A short list of 12 sites was finally arrived at in 1988. A further decision making tool was then required to help select the final target sites for detailed investigation. Four criteria were used to rank the 12 sites: 1) Safety both while the waste is being deposited and after the dump is closed. 2) Socio-economic and environmental impact including the attitudes of local communities to the nuclear industry. 3) Robustness or predictability of site geology, and ability to intervene to take remedial action following closure. 4) Cost. At the end of this exercise, Sellafield and Dounreay emerged as 'best of breed' sites. No details have ever been released concerning the whereabouts of the other 10 short-listed sites. Nirex are expected to announce in August 1991 that Sellafield has been chosen as their preferred site. A public inquiry is then due to be held in 1993. It will not be possible to process the data from the Sellafield investigation in time to produce a detailed safety case for the inquiry. Dr Ron Flowers, a Nirex Board member, argues that the public inquiry should only be concerned with simple planning matters. The adequacy of the geology, he argues, is a matter for the regulatory bodies, such as the Nuclear Installations Inspectorate. Nirex will apparently only be in a position to present a full safety case once the repository is actually built. The Chair of the government's Radioactive Waste Management Advisory Committee (RWMAC), Professor John Knill, has described this situation as 'unsatisfactory'. RWMAC have suggested a two stage inquiry procedure, the first dealing with infrastructure and approval for an exploratory deep shaft, and the second dealing with the full safety case. If it is unclear how Nirex will have sufficient information available to present a detailed safety case to the public inquiry in 1993, it is even less clear how they had sufficient information to choose between Sellafield and Dounreay as early as 1991. SELLAFIELD'S GEOLOGY The 1980 IGS survey had concluded that the potential of the sandstones beneath Sellafield for radioactive waste disposal was limited, with permeability likely to be too great and the sand too clean to allow for sorption (transfer from ground water to rock) of radionuclides to occur. Despite having been rejected as a potential repository site by the 1980 survey, a feasibility study for BNFL reported in 1982 on the potential for constructing a repository in one of several sedimentary rock types, including a sub-seabed repository in the St. Bees sandstone at an unnamed site (though obviously Sellafield). Later the St. Bees Shales, below these sandstones, became the focus of attention, but they are now thought to be too deep. The Borrowdale Volcanic rocks are now favoured as the repository host. These are a complex series of slightly metamorphosed (transformed by heat and pressure) volcanic rocks making up the central part of the Lake District. They underlie Sellafield at a depth of about 900 metres. The 1980 IGS survey highlighted the problem of forming a three-dimensional picture of Borrowdale Volcanic rocks: 'the nature of the volcanics . . . is speculative and a detailed prediction of the volcanic succession at depth cannot be made'. Faulting within these rocks will be extremely difficult to predict and map and 'limits the value of extrapolating formation depths from distant boreholes'. THE SELLAFIELD SITE INVESTIGATION Test drilling began at Sellafield in July 1989. The first borehole was drilled to the west of the Sellafield site. Drilling had to be abandoned, however, having failed to penetrate the Borrowdale Volcanic rocks at a depth of approximately 1,189 metres. Drilling of a second borehole began on 25th August 1990 to the east of the Sellafield site near Gosforth. This encountered Borrowdale Volcanic rocks at 467 metres deep. A replacement for the aborted hole began in late 1990. Detailed interpretation of borehole results takes about 12 months from the start of drilling. To claim to be able to choose Sellafield, in preference to Dounreay, on the basis of 2 boreholes, and as yet limited interpretation of vast amounts of complex data is, to say the least, premature. Given the fractured nature of the Borrowdale Volcanic Series, a large programme of boreholes and geophysical investigations will be necessary to even begin to understand enough to enable modelling of ground water flows to proceed. Tests will be carried out in the boreholes, but these will only be valid for a few tens of metres around each hole. A 1989 DOE report concluded that 'major fractures can be characterised during site investigation, but the majority of fractures cannot'. Model development is underway, but 'further development is required to produce tools suitable for use in performance assessment of repositories'. The potential for unidentified faults to exist in the Borrowdale Volcanic Series means there may well be a very complex ground water circulation. Indeed there are so many uncertainties concerning radionuclide behaviour and migration, that it may never be possible to model the real situation accurately. However, so confident were BNFL and Nirex that Sellafield would prove suitable, that on April 16th 1991, a fourth borehole began very near the site of the second. Planning permission has also been granted for 2 others close to it. A programme of up to 20 further boreholes is apparently planned, but complete data from these will not be available to a public inquiry in 1993. Two deep boreholes were planned for the geological investigation at Dounreay. The first one has now been drilled to a depth of some 1500 metres. The second, planned to go down to 800 metres, started in May 1991. How a decision regarding the suitability of Dounreay can be made on the basis of information from one borehole is unclear. THE DEEP DISPOSAL CONCEPT Deep geological disposal depends on the integrity of the containment, which must be reliable for many hundreds of thousands of years, and ensure that any subsequent release of radiation will not result in unacceptable radiological risks to either present or future generations. Nirex will rely on the 'multi-barrier' concept, which makes use of both engineered and natural barriers. Any assessment of safety at a particular site requires the calculation of the effectiveness of each barrier in preventing or retarding the movement of radioactive substances. This involves the use of highly complex computer models, which attempt to simulate the behaviour of the repository and the surrounding geosphere and biosphere. A considerable amount of uncertainty still surrounds the multi- barrier concept and the computer models which have to be used to evaluate each site. At a nuclear industry conference held in Paris in 1989 several speakers questioned whether it would ever be possible to model the natural world adequately. To quote one speaker 'the more you look, the more you need to look'. It is clear that a considerable amount of research still needs to be done before the technology and methodology for adequate site investigation and safety assessment is available. THE REPOSITORY DESIGN Running in tandem with the site selection process has been a repository design exercise. 'Generic' repository designs were produced in order to give a general impression of what a repository might look like, but they have no practical application in the real world. The feasibility of translating generic into operational designs 'depends on the assumed geology being a fair reflection of that actually existing' according to Nirex consultants. Due to the almost total lack of site specific information, details of geological conditions and estimates of the behaviour of groundwater flaws in relation to the local geology were greatly simplified. Rock formations were assumed by Nirex to be uniform, strong and without faults. This is far from an accurate portrayal of the geology at Sellafield, especially considering the number of fractures in the Borrowdale Volcanic rocks. Nirex plans to develop underground test facilities following construction of the access shafts, in order to finalise design parameters and assist in site characterisation. Since shaft construction cannot start until after planning permission has been granted, this provides further evidence that a full safety case will not be open to public scrutiny at an inquiry. RETRIEVABILITY The inherent idea of deep disposal is that of a sealed dump, which requires no further human intervention following closure. So it would be impossible to retrieve any leaking containers. However, the public consultation exercise which Nirex launched in 1987 concluded that the 'recoverability of wastes was generally deemed to be important. It was a principal concern for those who proposed above-ground storage'. The ability to recover waste containers conflicts with the multi-barrier concept, because the route used to recover the containers would provide a pathway for radioactivity to return to the human environment. Nirex say 'schemes for vault monitoring and waste retrieval must not compromise the integrity of the repository'. Ensuring post-closure retrievability would seriously affect the design. A larger excavation volume would be required and there would have to be a greatly improved ground- support system, to prevent early vault collapse. This has the potential, according to Knill, to produce more severe leakage of groundwater in and out of the repository, and more severe geosphere deformation, possibly resulting in local collapse of the excavation. There is a clear danger that retrieval may be offered in principle to gain public acceptance of the idea of deep disposal, only to become a hostage to fortune as its practical implications are realised. GAS GENERATION One of the most important potential pathways by which radioactivity could leak out of a repository, and back to the surface is the gaseous pathway. Gas will be generated by microbial action on organic material in the waste itself, and by the corrosive action of the water which enters the repository on concrete and steel structures. This has potentially important consequences. If gas is unable to escape from the repository, pressure may rise locally, and this could result in damage to the engineered structures or the opening of fissures in the surrounding rocks, which could in turn affect the groundwater movement. The volume of hydrogen alone that would be generated would be roughly equal to the volume of the waste itself every year for up to a few thousand years. If, on the other hand, gas is allowed to escape, it could provide a pathway for radionuclides. A recent Department of Environment (DOE) study concluded that research into gas generation and migration is 'very much in its infancy . . . considerable further work is therefore needed before the effects of gas migration could be included in a full assessment of disposal'. It is not clear how Nirex can rationally decide that a site is going to be suitable for development when there are still such major uncertainties surrounding the principle of the repository design. OVERSEAS EXPERIENCE Much is made by Nirex of the so-called international consensus on deep disposal of radioactive waste. In truth, much of the consensus is part of a mutual peer review system established by the nuclear industries of developed nations. Examination of this consensus reveals widespread uncertainties. Even when a repository has been developed, difficulties have arisen. Problems with gas generation in the shallow sub-seabed repository at Forsmark in Sweden are still not solved. Although commissioned in 1988, it has yet to be fully licensed for ILW dumping, which represents 90% of the total radioactivity destined for the repository. Throughout the Organisation for Economic Co-operation and Development (OECD) countries (the free market industrialised countries), the need for in situ research is accepted. In several countries it is intended to develop complete pilot repositories, which will never be used for actual waste disposal. Only in Britain is it planned to 'learn on the job'. In France, for example, site investigation for a deep repository for Intermediate and High Level Waste (Nirex has no responsibility for HLW) is expected to take 9 years to produce a preliminary safety report. This contrasts markedly with the 2 years of 'further investigation' proposed by Nirex before an Inquiry. CONCLUSIONS 1. If Nirex do announce later this year, as expected, that they have chosen Sellafield as the site for the deep disposal of low and intermediate level nuclear waste, their decision will be based on the results of only 1 borehole at Dounreay and 2 at Sellafield, together with some additional geophysics. This minute amount of data is totally insufficient for any meaningful site selection procedures. 2. If Nirex have been making decisions on political grounds, as many commentators suspect, it is only reasonable to question the validity of the deep repository concept and the suitability of the geology at Sellafield. When these questions are raised, it becomes clear that the Nirex decisions have been made with very little scientific evidence to back them up. 3. Despite the claimed international consensus on repository design, Nirex have only so far produced one specific design for Sellafield, based on an inappropriate rock type. Adaptation of a 'generic hard rock design' developed for elsewhere is now in progress, despite the lack of any real data. 4. The issue aweigh retrievability is likely to be put forward as a major 'selling point' in any public relations exercise, making conditions inside the repository even more difficult to predict, if not impossible. 5. Gas generation remains a major unknown. 6. It may never be possible to develop a computer programme which can adequately model conditions in the repository. 7. Given the delays in carrying out even the preliminary site investigations the danger exists that decisions to proceed will be based on incomplete information and interpretation due to the perceived need for a repository early in the next century. 8. Only in the UK is it proposed to 'learn on the job' during construction of a repository, and it is only in the UK that there is a lack of any firm proposals for the integrated management of all radioactive wastes, including high-level. The nuclear industry should address the waste problem in a unified and realistic way. There can be little confidence in an exercise which, having searched the whole UK mainland and continental shelf, identifies a nuclear site as the best candidate for a repository. THE GREENPEACE CAMPAIGN After a site selection process lasting nearly two years, Nirex have come up with nothing to detract from the conclusions of Richardson's earlier report i.e. that the deep disposal concept is seriously flawed. The very limited site investigations, and the fact that there will be little or no discussion of the safety case at a public inquiry, lead to only one conclusion-- Nirex's choice of site is based on political expediency alone. Greenpeace is opposed to the dumping of radioactive waste because: 1. Dangerous radioactive substances will leak out of the dump and pose serious risks to health and the environment far into the future. 2. It encourages the transportation of radioactive waste across Britain and the rest of the world. 3. It grossly misleads the public by pretending to be a 'solution' to the problem of radioactive waste. 4. It encourages an 'out-of-sight, out-of-mind' attitude and allows the reckless generation of radioactive waste to continue. There is simply no safe dose as far as radiation is concerned. Radiation can cause cancer, and some of the waste Nirex are proposing to dump will remain lethal for a quarter of a million years. Well before then, radioactivity from a dump could easily have seeped out into the surrounding environment and pose serious health risks to ourselves and to future generations. Greenpeace believes that the creation of nuclear waste through electricity production and the reprocessing of spent nuclear fuel should stop. Since there is no solution to the problem of radioactive waste it would be far better if none had been produced in the first place. Greenpeace believes that the radioactive waste which has already been created should be dealt with in the most responsible manner, placing considerations for the health of ourselves, future generations and the environment before political expediency. Greenpeace therefore advocates that all forms of nuclear waste-- including highly radioactive irradiated ('spent') fuel from nuclear reactors--should be stored above ground at the site where it has been produced in specially designed, fail-safe facilities so that they can be monitored and, if necessary, retrieved. Storage technologies are internationally proven. In the United States, Germany and Canada storage is already well established. The great advantage of storage over dumping is that the waste can be continually monitored which reduces the risk of an accident or leakage. Stores would be built beside nuclear power stations whose spent fuel and other waste they would contain. In addition storage facilities can be designed to be accessible to nuclear engineers or their robots--impossible in a dump, hundreds of metres deep underground. Managing the waste from nuclear power stations in this way also has the advantage of removing the need to transport this hazardous material, and thus removes the risk of a transport accident involving radioactive waste. The production of radioactive waste threatens not just ourselves but also passes on unquantifiable health risks and awesome responsibilities to future generations. After 40 years of nuclear power, the nuclear industry cannot guarantee the safe management of radioactive waste. There is no technical solution to the problem. The only answer is to stop producing any more. Meanwhile, above ground storage is the only way we can fairly compensate future generations for burdening them with our radioactive waste. Phil Richardson's full report 'Taking the Lid Off the Nuclear Dustbin' and his earlier report 'Exposing the Faults' are both available from Greenpeace, Canonbury Villas, London N1 2PN.