TL: RADIOACTIVE WASTE MANAGEMENT: THE ENVIRONMENTAL APPROACH SO: Greenpeace UK (GP) DT: unknown Keywords: nuclear power waste radioactive waste disposal greenpeace reports gp uk europe / GREENPEACE 30-31 Islington Green London N1 8XE Tel. 01-354 5100/01-359 7396 Briefing Paper Many concerned groups opposed to radioactive waste dumping and to nuclear power as a whole are united in calling for a halt to current and proposed disposal of radioactive waste and have proposed instead dry-storage at the site of production. This clear message was announced at a press conference in London on 12th November 1987, sponsored by Greenpeace, Friends of the Earth and Cumbrians Opposed to a Radioactive Environment. The policy was endorsed by 34 other groups, representing all regions of the United Kingdom, who passed the following resolutions: (i) There shall be no dumping or disposal of nuclear waste; (ii) Responsible and acceptable solutions to the problems of storage of nuclear waste should be sought; (iii) At present nuclear waste, including spent nuclear fuel, should be dry-stored in a fail-safe condition, above ground, on site at the facility at which it is produced, where it can be constantly monitored, retrieved and, if necessary, repackaged; (iv) The production of waste by nuclear power generation, and nuclear fuel reprocessing should cease. Moreover, the local groups made a firm commitment to support any community threatened by radioactive waste dumping by NIREX in the future. The groups stressed the need for today's decision-makers to act responsibly towards future generations and, since there is no current solution to the problem of this extremely hazardous and persistent material, 'acting responsibly' must mean not hiding the waste underground, but facing up to its existence. The following briefing paper is a direct response to the NIREX consultation process aimed at persuading the British public to accept the deep disposal of radioactive waste. It describes why the dry-storage of radioactive waste, an option excluded from the NIREX proposals, is the ONLY ENVIRONMENTALLY ACCEPTABLE means currently available to deal with this serious problem. This option is within the capability of current technology, can provide a significant margin of safety and environmental protection, and is already being developed and practised in several other countries. It is an option which the British public MUST be given. CONTENTS BRIEF I THE NIREX CONSULTATION EXERCISE BRIEF II A CRITIQUE OF DISPOSAL OPTIONS FOR RADIOACTIVE WASTE BRIEF III THE LAND STORAGE OF NUCLEAR WASTE APPENDIX I EXAMPLES OF ON-SITE STORAGE OPTIONS APPENDIX II INTERNATIONAL LEGISLATION APPENDIX III TECHNICAL NOTES November 1987 Brief 1 THE NIREX CONSULTATION EXERCISE A. Introduction NIREX have characterised their latest attempt at gaining acceptance for some form of nuclear waste disposal as 'letting the public decide'. Environmental groups have been involved in a number of previous 'consultation' exercises on the nuclear waste issue. We have also been provided with details of the latest consultation exercise from NIREX, and obtained a draft copy of the full consultative document some weeks ago. Although we remain open and receptive to a clear intent from NIREX to mend their ways, to properly 'consult' with the public and truly 'manage' nuclear waste, we remain sceptical for the following reasons: 1. The consultative document is narrow in context and scope, and does not adequately outline the overall problem of nuclear waste management in the UK. The omission of Sellafield as the main source and problem of nuclear waste is a major example of this. 2. The document expressly excludes any discussion of high level waste (HLW), even though most of the radioactive inventory is contained within this category. Any proposals for waste management which omit reference to HLW cannot be taken seriously, particularly where deep repositories are likely to be viewed as suitable for HLW disposal in future. 3. The general public are given no opportunity to assess the long-term storage of nuclear waste, even though this option is within the capability of current technology, can provide a significant margin of safety and environmental protection, and is already being practised both in this country and in many others. This is a major omission in the document, which in essence is a mere selection of dumping options. 4. Nor are NIREX giving the general public the choice as to whether they want any more radioactive waste to be produced. NIREX make much of the moral obligation not to pass the problem on to future generations. If they are truly concerned about the morality of passing the problem of radioactive waste disposal on to future generations, they ought to be more concerned about the morality of producing any more of it. 5. The track record for meaningful consultation is not a good one. Previous Consultative exercises, particularly those for the 'Best Practicable Environment Options' (BPEO) study into radioactive waste (1986) and the 'Draft Principles for the Protection of the Human Environment for Disposal Facilities on Land for Low and Intermediate level waste' (1985), (both Department of the Environment reports), resulted in little change from the draft report stage. The former study had a mere 11, mainly semantic, changes from the original draft. This is despite a series of detailed criticisms by environmental organisations and other groups. Environmental groups in the later 'consultation' exercise specifically called for a retrievable storage option for intermediate level waste, but this was ignored. 6. The consultation document is biased, in that a. it attempts to re-write history in its outline of the events leading up to the current exercise, and b. it does not give due weight to genuine scientific/technical uncertainties over certain of the disposal options. An example of the first point is shown in a chronology which neglects to explain why in 1981 the Government announced a new policy on high level waste, why NIREX withdrew from Billingham as a disposal site in 1985, and why NIREX withdrew from the 4 near-surface sites in Eastern England in 1987. All of these policy reversals were as a result of public concern and pressure, but no reference is made to this. Painful as it may be to state the truth, to present the current proposal as a logical policy progression is frankly misleading. An example of the second point is contained in a table listing the supposed advantages and disadvantages of each disposal option. The only disadvantage listed for the deep disposal site on land is "under someone's backyard". This distortion of reality, linked to NIREX clearly flagging up the "unproven" aspect of one of the sea bed options, clearly indicates that they are attempting to skew the reader towards accepting deep- land burial as the only feasible and 'proven' option. B. Additional notes on the consultation process From correspondence with NIREX, the following points emerge: 1. The consultation process will last six months. Initially 300 organisations will be involved. 2. All local authority associations and strategic planning authorities in the UK will be sent copies of the NIREX document, but not district councils. 3. It is not intended to hold public meetings. Around half a dozen selected 'invitation only' meetings, involving local authorities, scientific and technical bodies, trade unions etc., will be held. 4. The results of the exercise will be analysed, although NIREX say they have not yet decided how, and are "talking to the Department of the Environment and a university in this context". 5. The results of the exercise will be made "publicly available", although NIREX want to "respect the privacy of individuals or organisations responding". In reality this means that a summary of the findings, rather than the raw data, will be provided. C. Are NIREX an appropriate body to draw up the consultation document and carry out the whole exercise? No. NIREX plc are, in the words of the Royal Commission for Environmental Protection, "entirely a creature of the nuclear industry". As such, they cannot question the policies or motives of bodies such as BNFL, SSEB and the CEGB who produce the waste or the Department of Energy who condone reprocessing. They cannot question the choice of reprocessing as a waste management option, which increases the volume of radioactive waste by a factor of 10, and which has no economic or waste management justification. NIREX are limited in scope and have no remit for high-level waste or the long-term storage of waste. They are simply a small technical/public relations body who carry out the wishes of the nuclear industry and government. If the majority of public desired long-term storage on the site of nuclear reactors as a feasible option, NIREX have no mechanism or remit to approve this option. D. Conclusion - the criteria for assessing the validity of the 'consultation exercise' If 'consultation' is to have any credence, there must be a clear commitment towards taking account of the views of those consulted, even if these run contrary to government and nuclear industry policy. The exercise must not artificially limit the choices available, otherwise the public are simply given a choice of variations on the same theme. The 'facts' presented to the public must also be just that, omitting nothing even where the truth is embarrassing. On the evidence presented so far, we are far from hopeful that the above criteria will be met by NIREX and its consultation document. Brief 2 A CRITIQUE OF DISPOSAL OPTIONS FOR RADIOACTIVE WASTE. 1. Description of Waste Categories See Appendix III 2. UK NIREX Ltd Deep Repository Concepts for Radioactive Waste Disposal All three proposals by NIREX, euphemistically called "deep repository concepts", are simply deep burial concepts. Burial is the common link between NIREX's three options and the principal objections will be common therefore to them all. The three options are: Sub Sea Bed Repository Accessed from the Sea. The construction of a repository under the sea bed with access from a mobile or fixed platform, or even an artificial island. Sub Sea Bed Repository Accessed from the Shore. In concept this is similar to the underground repository, but it is situated beneath the sea bed and accessed by shafts and tunnels from a site at the coast. Underground Repository. A shaft or inclined adit is constructed to the desired geological horizon. Tunnels or caverns, depending on rock strength, are then excavated and supported as necessary to act as disposal areas. Using suitable underground transport, the waste packages are lowered through the shaft or ad it and driven to disposal areas where they will be stacked.1 3. Specific Criticisms of NIREX Disposal Options Sub Sea Bed Repository Accessed from the Sea A. The seabed emplacement of radioactive waste in international waters would contravene the position presently taken by the London Dumping Convention, and in national waters would contravene the spirit of the same Convention. Any attempt to implement such a practice would therefore meet with considerable international opposition. (See Appendix II). B. There will be no guarantee that the shaft or bore-hole (particularly as in the case of the CET proposal where the shaft could be up to 3000 metres deep) will retain its integrity. In fact the zone of rock mass effected by an excavation increases with the square or even the cube of the largest dimension of the excavation.2 C. It will stretch oil drilling technology to its limits without guarantee that it will be successful and safety problems will arise with respect to workers operating deep under the seabed. Within the shaft itself major technological problems are likely to arise from the kind of depths envisaged, particularly hoisting problems.3 D. The monitor ability and retrievability of the waste (to include all categories) is doubtful especially over any length of time. Moreover any retrieval operation is likely to run into difficulties in severe weather. E. The excavation of a shaft 15 m in diameter as proposed by CET, will generate large quantities of spoil (up to 500,000 m3)3 that will have to be disposed of. F. The sealing and capping of large holes may not be feasible.3 G. Transportation of high active waste to the shaft will be hazardous and problematic.3 H. The NIREX paper (Deep Repository Concepts For Radioactive Waste Disposal) states: "Further study and development is required to determine the feasibility of access from a sea based platform".1 I. Such a means of disposal forecloses the options for future improvements in containment technology and concepts. J. The temptation will be to use any such under seabed route as an out of sight out of mind dump with all manner of nuclear waste being disposed of without proper surveillance and control. Sub Sea Bed Repository Accessed from the Shore Objections to this proposal include some of those already stated for the vertical shaft route, for instance, the contravention of the London Dumping Convention, as well as technical problems with monitor ability and retrievability. Other objections include the proximity to land where access tunnels facilitate a direct pathway for radionuclides back to the terrestrial environment. There is a high probability of water intrusion as a result of dramatic climatic changes including ice ages and global warming which will affect the sea level. As with the concept employing access from the sea such a route of disposal will constitute a slow form of sea dumping through leaching. In the case of the concept being deployed from the Sellafield site, this will add to the already high radioactive contamination of the Irish Sea. Moreover, the engineering exercise required to place the disposal caverns well within the anhydrite evaporites off St. Bee's Head (requiring an access tunnel of some 17 kilometres in length) would be a massive project. Such an undertaking would generate waste quantities of spoil which would itself need disposal. The recent decision by British Nuclear Fuels to abandon this concept is to be commended. Underground Repository In common with seabed sites, the same concerns over geological integrity prevail as will be discussed below. There is also a risk of ground water contamination. UK NIREX have confirmed that "the Billingham mine is the only existing natural or man-made cavern which we know, that appears to have potential for waste disposal". They have also stated that they would respond positively if "a change of policy of both the government and the owners (would) allow us to revive any interest in the mine".4 The need for geological research in the search for disposal sites is seriously underestimated. Although Britain is geologically one of the best known areas of the earth's surface much of the research has been of a superficial nature aimed at producing geological maps for general application. These are inadequate for specific applications such as repository site selection. In the evidence to the Environment Committee 5 (Vol.2 p.559) "there has been a very extensive general study of the geology of the UK which indicated that over 15% of the geology appears to be suitable for the most dangerous radioactive waste and some would be suitable for the less radioactive wastes". In fact no study has been carried out in the UK that could possibly conclude that 15% of the geology is suitable for this method; the work has not been done. The British Geological Survey has indicated that about 16% of the UK has potentially suitable rocks but the suitability of these rocks for a programme of radioactive waste disposal has not been fully undertaken. In a statement to the House of Commons 6 in July 1979 the Secretary of State for the Environment said "only when full information is available, and has been properly evaluated will it be possible to judge whether or not disposal deep underground is an option to be pursued".7 4. The Principal Risks of Radioactive Waste Disposal The three principal concerns are: A. Migration of Radionuclides through Geological Processes. Radioactive elements may be transported - for example by the ingress and flow of water through the waste - away from their original location and reappear elsewhere in a form which was not foreseen. Radionuclides could find their way into sources of drinking water. Transportation mechanisms, which vary considerably for different elements, are poorly understood. Already there have been some unpleasant experiences; of six commercial low level radioactive waste dumps in the United States three have been closed due to off-site radioactive contamination.8 B. Disruptive Geological Events The normal, apparently benign geology of a particular site may be disrupted by gradual movement or by infrequent though violent events such as earthquakes. The occurrence and effect of these events, both gradual and sudden, is difficult to predict. The United Kingdom does experience quite severe earthquakes from time to time. A quake which reached 5.5 on the Richter Scale struck large areas of the West Coast of England and the Irish Republic in 1984. This was considered to be 'pretty big for Britain' according to the Global Seismology Unit at Edinburgh. C. Human Intervention A nuclear waste repository could be deliberately or inadvertently interfered with by people. There are many examples of this occurring at waste dumps of other toxic materials and it is particularly problematic if waste is disposed of close to human habitation. The use of uranium mill 'tailings'( the wastes created by the process of uranium extraction from the ore) by thousands of people as foundations for their homes and who are now experiencing radiation exposures equivalent to 500 chest X-rays a year, 9 is an example of the hazards of inadvertent interference with radioactive waste. Human intervention may also result through causing geological subsidence by mining, mineral exploration and other related activities. The construction of any form of radioactive waste disposal facility must be dependent upon a very high degree of confidence that the above problems will not arise during the time periods of concern.9 5. The Multi-Barrier Waste Isolation Concept The conceptual strategy which is currently accepted for dealing with the disposal of radioactive waste is called the "multi- barrier approach". A "barrier" being an obstacle to the passage of radionuclides towards the biosphere and hence to people. Consideration of the technical issues is largely a matter of trying to determine the performance of each of these barriers as well as all of them collectively over the total time span of the repository. The individual barriers in the multi-barrier concept are as follows: - the Time elapsing prior to disposal - the Form of the waste - the Canister in which the waste is sealed - the Backfill - the material packed in after the canister has been placed in position - the Near Field - the immediate surrounding engineered/geological environment - the Far Field - the more distant geological environment - the Biosphere Each barrier is intended to have the effect of successively reducing radioactive doses to the population compared to the dose obtained directly from the waste. However the effectiveness of these barriers can be reduced by many different factors such as temperature, acidity, radiation itself and time. One particular area of concern is the corrosion of canister materials. "The interaction of ground water, rock and waste package chemical constituents, thermal and radiation fields, microbial effects and mechanical stresses must be better defined". "Further realistic tests will be necessary because even though each of the subsystems (barriers) is investigated in detail the possibilities of overlooking synergistic, mutual interactive processes cannot be ignored".10 The multi-barrier concept places ultimate faith in the ability of the far field to contain the radionuclides because: a. because of the difficulty of detecting and retrieving damaged, leaking canisters, b. the leaching of radionuclides into rock formations would be extremely difficult to remedy, c. canister and back fill materials may break down before waste is rendered "radiologically harmless" 1 6. Geology Geology is a retrospective not a predictive science. "Of the various barriers in the multi-barrier waste isolation concept......... the geological barrier is the least well understood".7 The problem therefore is one of predicting the behaviour of radionuclides flowing through fractures in host rock formations. Although various attempts have been made to describe the flow in fractured media, "none of the (proposed) theories has proven adequate enough to be universally applicable nor is one likely to prove" hence a "site-specific" approach is necessary. However, this will only be adequate if it accurately predicts the flow both over space and time, the question of prediction over time being "certainly much more difficult".10 Predictive mathematical models are limited devices which serve to formulate and refine hypotheses. Mathematical models are commonly based on simplifying assumptions many of which are erroneous. For example it is assumed that permeability decreases with depth; this is often not the case since major hydrogeological features can be encountered at considerable depth.7 Regardless of disposal, storage or pre-storage disposal options important radionuclides, principally isotopes of elements such as Cs, Sr, Sm, Am, Sb, Pu, Np, Te, Zr, Sn, Se and Pa which would produce major artificial activities over long time periods, need particular assessment. There is no significant data base on the detailed marine and geological behaviour of many of these isotopes.11 Tectonic plate movement has only been a scientifically recognised geological process over the past thirty years. Furthermore dramatic climatic changes can occur over what are extremely short periods in geological time. The last ice age ended only 12,000 years ago and crystalline rocks are still fracturing as a result of the rebound caused by the alleviation of pressure from the retreating ice. The greenhouse effect is likely to lead to significant changes in sea level in the next 100 years thus effecting coastal areas with implications for waste disposal sites.2 In terms of prediction there are several different aspects to the problem: a. the measurement of radionuclide migration over a long distance, b. the evolution of the rock formation over time, both naturally and with the consequences of the presence of the waste, c. how human activities which are not associated with the repository (eg boring, mining well drilling etc.) will affect the predictive modelling, d. how human activities which are associated with the repository (eg., backfilling and sealing the repository) will affect predictive modelling. The retardation of nuclides (the factors that might slow down the nuclide migration) are measured by "a rather brutal averaging technique" which "for a scientifically rigorous performance assessment.... is inadequate and must be replaced...".10 The possible presence and behaviour of organic life may lead to the mobilisation of otherwise insoluble isotopes and to the degradation of canisters and backfill and also to effect the fracture network in the host rock. No geologic formation can be proved in the very long run to be entirely safe from the danger that water will reach the wastes and that radioactivity will be released into the environment, especially if the ion exchange capability of any matrix into which the waste is mixed breaks down, or if a hydraulic gradient exists in the formation. Therefore a geologic formation should not be considered a confining barrier for radionuclides with very long half lives. At best disposal is a method for delaying the release of these radionuclides and its feasibility depends on the ability of the upper environment to receive the flux of elements and eventually dilute them. Thus neither the thickness of the geologic formation nor its low permeability are major factors in confining radionuclides with very long half lives over periods of time on a geological scale.12 7. Biosphere Once again prediction is the major problem in considering the effects of radionuclides on organic life and also in terms of important changes which can take place in the biosphere. For example, in the last century, acidification, silting of lakes, deforestation have occur Ed and as already stated, in periods of thousands to a few tens of thousands of years, we can expect major climatic changes and species variation. This makes the calculation of doses at far distant times with any certainty a difficult task. It is worth noting that 7,000 years ago the English Channel was dry, the sea level being 100 metres lower than at present and the Sahara Desert was partly fertile. Iodine 129, Neptunium 237 and Plutonium 239, which are present in spent fuel waste in significant quantities, all have substantial half lives and moreover have a very wide range of physico-chemical properties that are of importance in their interaction with rock formations. 12 Bibliography 1. A.W. Davies, Deep Repository Concepts for Radioactive Waste Disposal, UK NIREX Ltd. 2. W. F. Fyfe et al, The Geology of Nuclear Waste Disposal, Nature, Vol.310, 1984. 3. A. Dickey and V. Wyman, Burial At Sea, The Engineer, October 1987. 4. Correspondence from P.J. Curd, UK NIREX Ltd., 27/10/87 to FOE. 5. First Report from the Environment Committee on Radioactive Waste, 1985-6. 6. 26/7/79 7. M. J. Heath, The Long Term Geological Isolation of Radioactive Waste: An Assessment of UK Policy on Research and Disposal, 1986. 8. R.D Lipsschutz, Radioactive Waste: Politics, Technology and Risks, Union of Concerned Scientists 1980. 9. R. Chudleigh & W. Cannell, Radioactive Waste: The Grave digger's Dilemma, Friends of the Earth 1985. 10. F.L. Parker,R. Broshears & J. Pasztor, The Disposal of High Level Radioactive Waste 1984: A Comparative Analysis of the State-of-the-Art in Selected Countries, The Beijer Institute. 11. M.S. Baxter, Disposal of High Activity Nuclear Wastes in the Oceans, Marine Pollution Bulletin, Volume 14, No.4, 1983. 12. G. de Marsily et al, Nuclear Waste Disposal: Can the Geologist Guarantee Isolation? Science, Vol.197, 1977. 13. Implications of Long Term Surface or Near Surface Storage of Intermediate and Low Level Radioactive Waste in the UK, DOE, 1986, No.DOE/RW/86/053. 14. Environmental Resources Ltd., The Future Disposal of Low and Intermediate Level Nuclear Wastes in the UK. 15. Correspondence from P. T. McInerney, UK NIREX Ltd., 24/9/87 to Greenpeace. Further Source Material P. Prescott-Clark and A. Hedges, Radioactive Waste Disposal: The Public's View, Social and Community Planning Research, 1987. C. W. Bullard, Issues in Radioactive Waste Management, Central MidWest Compact Commission for Low Level Radioactive Waste Management, 1987. Brief III THE LAND STORAGE OF NUCLEAR WASTE Introduction First and foremost, the NIREX proposal is directed to only a small proportion of the nuclear waste, measured in terms of radioactivity (but not bulk), categorised as 'low' or 'medium' active waste. The great majority of radioactivity, perhaps as much as 95% must be stored above ground for many decades to come, and certainly there will be such above ground storage for the life of the nuclear industry. This non-disposable waste is known as 'high' active and NIREX has no proposals for its disposal beyond a conceptual stage. Thus, surface storage of this dangerous high active material has been employed over the past 30 or 40 years and will be needed for the foreseeable future. The low and medium active wastes pose less of a problem to storage because they are less concentrated; those that are liquid are most easily solidified; they do not generate heat sufficient to require cooling. However, they are bulky and this increases costs. In general they contain much the same type of radioactivity as the high level wastes but in a less concentrated form. Much of the low level waste actually contains relatively short lived and much less toxic radionuclides. Integrated waste management Modern environmental awareness in relation to toxic materials is moving towards containment rather than dispersal. All computer models so far utilised for deep underground or undersea disposal show that dispersal of contents is expected to take place at some time in the distant future (often more than 10,000 years). Thus all disposal is ultimately dispersal. Deep disposal gives an immediate but ultimately false sense of security except perhaps to that population and generation that produced the waste. Geological and oceanic processes at depth are not fully understood and computer predictions by models cannot be tested and hence validated. It is thus reasonable to argue that waste producers should be confronted with the reality of their activities and be obliged to store the waste and invest in the best available technology for containing the waste forms and making them resistant to the well understood surface environments. Any policy that seeks to take the least problematic material constituting a small percentage of the toxicity, burying it within a short time period (say the next 10-15 years) and hence proclaiming a 'solution' is obviously a policy capable of grossly misleading the public. Moreover, it would act as a self- deception to those industries producing the wastes, which would carry on as if a problem did not exist. It would further act to influence other industries and governments considering expansions of power generation, isotope usage in food sterilisation, radiography etc. Thus major commitments could be made which would not only exacerbate future management problems, but also compromise the environmental safeguards which might prove too costly. Basic tenets: - an integrated waste management policy must be adopted for all nuclear waste, from low to high active forms, - there is no 'solution' in terms of a no-risk disposal option and acceptability must therefore be found in the broadest political sense, - there is a majority in favour of curtailing the expansion of nuclear industrial uses (and in the case of weapons requirements, the likelihood of such reductions as would leave no further military requirements), - the Sixth Report of the Royal Commission on Environmental Pollution also stated that "there should be no commitment to a large programme of nuclear fission power until it has been demonstrated beyond reasonable doubt that a method exists to ensure the safe containment of long-lived highly radioactive waste for the indefinite future". In other words the Commission argues that there should be no commitment to any programme of nuclear fission power without a proven waste disposal strategy: no such strategy exists or is likely to be proven, - therefore, everything should be done to confront the waste producers with the consequences and costs of their activities, - these tenets are best served, at this time, by a waste management strategy that integrates low and medium level wastes with high level storage sites for the life of the nuclear industry, The long term: - during the current life of the nuclear industry waste materials must be securely stored in a fail-safe condition facilitating the option to adopt improved containment technology at a future date, - during this time research into long term stability and resistance to environmental factors must be carried out, - decisions may be taken toward the end of that time when high level wastes must still be stored above ground because of their residual heat, It should be noted that nuclear industries are already required to put funds aside for future waste management costs. The adequacy of these funds must be reviewed in the light of the likely stringent standards that will be required. Technology: Some research and scoping studies have already been carried out in the USA and Canada where it is increasingly felt that above ground storage may become the most acceptable repository. Appendix I shows schematic illustrations of some examples of technology for the dry storage of spent fuel or activated wastes under development or in operation in several countries. It can readily be concluded that surface storage of these waste types requires no new technology, although research programmes and cost assessments should assess the best available technologies for reduction in volume, solidification, packaging and containment such that risks to workers are minimised and resistance to leaching and other environmental factors is maximised. In this regard, the concept of Quasi-monoliths, massive structures that are both resistant to weathering and to vandalism/terrorist intrusion, (the waste form being therefore non-dispersable) with additional marking such that a bio-hazard may be obvious across many generations, has been developed. Such structures would be similar to monuments such as the pyramids of Mexico and Egypt and be expected to remain intact for tens of thousands of years. Their massive construction and marking would act as a warning and deterrent for any future generation that did not have the technical knowledge to protect itself, or to use the material in such a way that dispersal could take place. It should be noted that within 300 years of the last waste being generated, the waste forms will emit very little penetrating radiation, and the hazard will be chiefly due to the long lived alpha emitters. These radionuclides are only toxic if ingested or inhaled. Research should therefore concentrate on making this long lived material as resistant to weathering as is technically feasible. In conclusion, the above integrated context for waste management should determine the research and development strategies. These will need to focus upon the long term immobilisation of the longest-lived activity, having regard to the likely environmental conditions. Potential objections to land storage 1. Accessibility This was identified as of prime public concern in a survey by SCPR on waste management options. The main fear was that vandals or terrorists could gain access to the waste. This concern is seen to be unjustified for the following reasons: i) low and intermediate waste are not suitable materials for terrorist purposes, being of high bulk and low dispersal potential and for the most part low radiotoxicity. The high- level wastes currently stored do have such a potential, and although it is outside the NIREX terms of reference, any storage strategy must include proposals to make these high level stores fail-safe. Protection against vandals and/or terrorists can be best assured by using massive construction for individual waste-form canisters and a matrix material that would make retrieval of the actual radioactivity a laboratory procedure. ii) terrorist groups that would have the expertise to isolate plutonium in a usable form from wastes would need vast financial resources. Such groups can already purchase radionuclides for this purpose either legally or illegally. 2. Proximity to People This was also a major concern expressed in the SCPR survey. There is no way around it: if wastes are to be easily monitored and controlled, they must be accessible to supervision by trained and experienced personnel. Nuclear power sites are usually in sparsely populated areas and so this is some compromise. The main point in relation to this argument is that low and intermediate level wastes would not significantly increase the present risk profile of the producer sites, most of which hold high level wastes and/or reactors where much larger quantities of radioactivity exist in dispersible form. Thus, the storage of low and intermediate level waste on-site will not pose significant additional risks to those populations presently at risk. In the longer term, this policy can be reassessed when reactors and other producer installations are decommissioned. At that time, an integrated policy may be developed for all classes of nuclear waste. 3. Environmental factors Surface stores are closer to those violent environmental influences such as storms, floods, sea-level changes, freezing etc. However, this is also true of high level waste stores and operating reactors which must be so protected for the life of the nuclear industry. Thus, low and medium active wastes will not increase this risk profile over this time period. In the very long term (several hundred years) these factors will dominate the decision making where the advantages of surface stores (monitorable, under control, retrievable etc) must be weighed against the increased distance from human via deep disposal. However, forces operating at depth may be just as severe and unpredictable in the long term as those at the surface. In principle, above ground stores utilising massive construction and leach resistant materials could provide the required resistance to environmental factors, and may prove more resistant, particularly in drier environments. These kind of comparisons require detailed modelling and evaluation. Bibliography N. Bradley, E.A. Brown, "Natural Draught Centralized Dry Storage for Irradiated Fuel and Active Waste", Nuclear Engineering International, November 1981 David Deacon, "The Developed Technology of Modular Vault Dry Storage", Nuclear Engineering International, April 1984 Human Interaction Task Force, "Reducing the Likelihood of Future Human Activities That Could Affect Geologic HLW Repositories" technical report prepared for ONWI, May 1984 Nuclear Energy Agency, "Operating Experience of Vault Type Dry Storage and its Relevance to Future Storage Needs", May 1982 D. S. Wheeler, "The Effect of Known Clad and Pellet Reactions on the GEC/ESL Design of Dry Vault Store", Workshop on Spent Fuel/Cladding Reactions During Dry Storage", August 1983 Appendix II International Legislation on the Disposal of Radioactive Wastes at Sea Sea Dumping The 1972 Convention on the Prevention of Marine Pollution by Dumping of Wastes and other Matters (the London Dumping Convention - LDC) is the intergovernmental forum seeking "to promote the effective control of all sources of pollution of the marine environment". Its jurisdiction extends to international waters. More than fifty nations have signed the LDC which takes the following position on sea dumping: * As material listed under Annex 1 of the LDC, the dumping of high level radioactive wastes at sea is explicitly prohibited. * At present, the dumping of all radioactive wastes is subject to an indefinite moratorium. Until recently several countries maintained large programmes for dumping "low level" radioactive wastes in the sea in drums over the sides of ships. In February 1983, at the Seventh Consultative Meeting of the Contracting Parties to the LDC, a resolution was adopted by an overwhelming majority calling for "the suspension of all dumping at sea of radioactive materials" until such time as scientific and technical information could be assembled to provide the terms of reference for a permanent ban on all radioactive waste dumping. (A permanent ban would be enforced by an amendment to Annex I of the Convention such that all radioactive matter regardless of the level of radioactivity would be placed on Annex I). Directly after the vote, the UK, Switzerland and Belgium announced their intention to continue to dump despite the resolution. However, at the initiative of the National Union of Seamen, the International Transport Unions Federation representing over 300 unions in 65 countries, organised an international boycott of sea dumping operations. 1983 was the first year since World War II during which no nuclear waste was dumped in the world's oceans. At present, work is still proceeding on formulating the terms of reference. The indefinite moratorium on the dumping of all radioactive wastes at sea anywhere in the world is still in effect. Sub Seabed Emplacement The technique of "sub-seabed emplacement" involves the drilling of bore holes into the sea bed, and then filling these with radioactive wastes from a vessel or structure stationed above. It is argued by those countries with the greatest unsolved waste problem that such a system does not constitute "dumping at sea" since the final resting place of the wastes is not the sea itself but the sea bed. In 1983 a technical working group of the LDC was convened to assess the legality of sub-seabed emplacement and whether it should be subject to the prohibition of Annex 1. The group failed to come to any firm conclusion either way, but consensus was subsequently achieved at the 1984 meeting of the LDC that: 1. the LDC is the appropriate international forum to address the question of the disposal of high level radioactive waste into the seabed, including the question of the compatibility of this type of disposal with the provisions of the LDC and, 2. no such disposal should take place unless and until it is proved to be technically feasible and environmentally acceptable, including a determination that such waste can be effectively isolated from the marine environment, and a regulatory mechanism is elaborated in accordance with the provisions of the LDC to govern the disposal into the sea bed of such radioactive waste. Beyond this basic agreement, two principal blocks expressed notably different views on the legality issue. The dominant coalition of nations - a large majority of those who stated a posit on - argued that high level waste disposal is covered by the LDC and prohibited. These nations agreed that protection of the marine environment under the LDC requires an interpretation that views seabed disposal as "disposal at sea". This view was expressed in a draft resolution sponsored by 17 nations. Six nations, including the UK, submitted a draft resolution which took the view that seabed disposal is not covered by the LDC as now written and therefore is not prohibited. Since a number of delegations were concerned about forcing the legality issue to a formal vote both draft resolutions were attached to the report of LDC 8 but not voted upon. At the tenth meeting of the LDC in 1987 eight additional nations expressed their support for the draft resolution opposing sea-bed emplacement. If any nation embarks upon a plan to dispose of radioactive waste in the sea bed, (regardless of the level of radioactivity of the waste) it is highly probable that it will meet with strong international opposition within the, LDC. Appendix III Technical Notes Low Level Wastes These consist mostly of high volume low concentration contaminated rubbish including paper, plastics, clothing, building materials etc. The activity is mostly short-lived, with caesium and strontium being the longest lived (30 years half- life). No long lived alpha should be included. This waste form is the least problematic in terms of hazard, requiring chiefly the protection of workers during the handling. The use of cement and/or bitumen as matrix and steel or concrete containers presents no technical difficulties. The main problem is the high volume and hence cost of container materials and storage space. However, because of the low hazard potential, even several million cubic metres should present no major land- take and building problems if located within the perimeters of current nuclear sites. These volumes are minuscule compared to UK annual domestic refuse, coal spoil, quarry wastes etc. Intermediate/Medium Level Wastes These consist of higher concentrations and are in the form of solid and semi-solid items such as glove boxes, process cabinets, sludges, resins, and other pieces of equipment. Cement, bitumen, and ceramic materials may be used for solidification in the case of problematic materials such as the sludges and resins. Shielding requirements make containers bulky and expensive. Overall volume is still high. These wastes include large amounts of alpha-activity with very long half life such as plutonium isotopes. These wastes are categorised as non-heat generating. They are thus potential candidates for the NIREX 'disposal' options. However, they are less problematic than the liquid high level wastes and should therefore be integrated into the long term management of these wastes which must be solidified and stored. They present a small additional hazard relative to that from spent fuel of HLW liquids and could therefore be integrated into nuclear site storage programmes. Some very bulky items (e.g., reactor internals) might be left in place as they are shorter- lived and not dispersable. High Level Liquid Wastes, Plutonium and Spent Fuel Depending on how nuclear fuel is subsequently treated the waste will consist either of intact spent fuel rods or liquid waste resulting from reprocessing the fuel. There are several problems yet to be solved, such that high level wastes are not at present capable of handling and transport and hence are not deemed 'disposable'. Firstly liquids require either vitrification or cementation. Secondly heat output requires either active cooling (when in close storage) or convective cooling if less dense systems are chosen. Massive shielding is required. In the case of plutonium (which may become surplus to requirements for failed FBRs or defunct weapons), effective security is required, as well as protection from criticality and combustion. In the case of spent fuel there are several research programmes looking at long term dry storage using natural convective cooling and massive intrusion resistant flasks (Castor flasks, West Germany). For surface repositories, large vault systems would be required. Similar investigations must be pursued for vitrified liquid blocks. The large tonnages of plutonium require assessment: no disposal options have been proposed and they are currently stored.