Managing Radioactive Waste Safely

Managing Radioactive Waste Safely

The Royal Society of Edinburgh (RSE) is pleased to respond to the Scottish Executive Environment Group on the national consultation on managing radioactive waste safely. The RSE is Scotland’s premier Learned Society, comprising Fellows elected on the basis of their distinction, from the full range of academic disciplines, and from industry, commerce and the professions. This response has been compiled by the General Secretary with the assistance of a number of Fellows with experience in this area.

Overall, the consultation document is broad in scope and sound in factual basis. In particular, the involvement in its production and proposed action plan of a range of public stakeholders and its general openness are to be commended. However, following the cluster of terrorist attacks in USA on September 11, 2001 the enhanced perception of terrorist threat has profoundly impacted on many security aspects of radioactive waste disposal and storage, greatly increasing the technical requirements and shortening the desired timescales.

A critical aspect of the consultation is whether the fuel potential of the accumulated waste should in future be used or destroyed. The new generation of nuclear facilities could offer much to future society and its environment through CO2-free energy, making positive energy uses of UK’s nuclear wastes in line with the needs of future generations of nuclear power reactors. However, given the link between nuclear power and the weapons programme, the past accidents and the constant communication failures of the nuclear industry in this area, it is understandable why the public (and politicians) might have reservations about the inclusion of a component of nuclear energy in future plans. Therefore, if nuclear energy is to recover in future and if nuclear wastes are to be used positively, then a dynamic programme of supportive public dialogue will be required.

The fact that existing stores will be adequate for 50 years is used throughout the document to give a sense that there is plenty of time. However, it is over two years since the House of Lords Science and Technology Committee Report on the Management of Nuclear Waste, seven years since the Royal Society of London’s report on the Disposal of Radioactive Wastes in Deep Repositories and 25 years since the Royal Commission on Environmental Pollution Report on Nuclear Power and the Environment. Yet there is still no policy.

The specific issues identified in the consultation paper are addressed below:

How have radioactive wastes been managed up to now?

Views are invited on the principle of segregating UK waste types by half-lives
While full advantage should be taken of the decay during storage of shorter-lived nuclides in radioactive waste, the idea of segregating wastes according to half-life may be unrealistic. All waste types contain a range of half-lives and some wastes will require lengthy processing to achieve separation and in the course of which large volumes of low level waste may be produced. The hazard to operatives and the consequential increase in the volume of low active waste has to be balanced against the potential benefit. Nevertheless, selected cases could be pursued and future disposal routes investigated, where practicable, according to this principle.

It should also be noted that toxicity is a function of nuclide chemistry and physical form, as well as radiological property, therefore it makes little sense to use half-life as the sole segregation criterion. There is therefore a need for a more flexible approach to waste classification based upon a combination of half-live and radiological significance.

Defence
The decision to bring defence related waste under the provisions of the civil regulatory regime for purposes of storage and disposal is to be welcomed. Without this decision in principle, it would be difficult to develop a holistic policy.

Small Users
The problem of how best to dispose of technologically enhanced natural radioactivity associated with a wide range of non-nuclear industries is important and the Society believes that careful consideration should be directed to this matter. A case could be made for the total equivalence of protocols for disposals of wastes from the nuclear and non-nuclear industries. In the context of oil and gas industry sludges, the Society supports consideration being given to injecting such wastes into the seabed as the best practicable environmental option and to limit any potential leakage back to the seawater column. However, there will be differences in chemistry, physics, geology, and hence in mobility and containment between source rock and waste sludge, and by definition such disposal sites would be in shallow water (and hence less suitable generally as repositories).

Spent sealed sources
The Society supports the Radioactive Waste Management Advisory Committee’s (RWMAC) proposals for the management of spent sealed sources. Although no known serious accidents have yet occurred, it is apparent from other world experiences that unknown or unrevealed losses are a main safety concern. New resources, financial and organisational, should be found to allow adequate recording, management and disposal of these sources. The proposed "dedicated organisation" need not, however, be a totally new organisation but rather one which has experience of, and perhaps responsibility for, other wastes. This would enhance safety, by sharing expertise, while reducing cost. There is also an additional practical problem which could be looked at: authorisation is not needed, from the Scottish Environment Protection Agency (SEPA) or the Environment Agency (EA), for disposal under the sealed source exemption order but it is needed if the material is declared as waste, with disposal authorisation often taking a long time to obtain. Financial ring-fencing to allow for proper management of existing wastes by Universities and medical research centres is also necessary.

What wastes still have to be managed?

Waste substitution
The policy of waste substitution could be justified wherever its use reduces the need for international shipment of nuclear materials, with reduced shipment broadly equating with improved nuclear security. While the policy will insignificantly change the total activity being disposed of by each country, there will, however, be a need to convince customers and the public of the validity of this approach, if what is substituted is not equivalent to that sent out. It will also need to be considered in light of the UK’s long term strategy for the management of intermediate level wastes.

Issues to be Considered in Developing Decommissioning Strategies
The Society supports the general approach to decommissioning outlined in the document and all new plant should be designed with decommissioning in mind. System-conversion should also be considered.

Plutonium
Since the Consultation document was issued, a Mixed Oxide fuels (MOX) plant has received permission to operate. Once preliminary operating experience of MOX fuel has been documented, it would be appropriate to revisit the plutonium inventory. The Pu presently in storage (not all of which is immediately suitable for fuel) represents an enormous potential for C02-free energy production. Therefore no decision on its future should be made without (i) operating experience on MOX fuel, (ii) further research on more efficient processes for the separation of Am and Pu and (iii) a decision on the construction of new nuclear plant which might, for example, be specially designed around MOX fuel. In the interim, better arrangements need to be made for safe storage with enhanced provision for monitoring. What the September 11 events also necessitate is improved physical security of separated plutonium storage, sufficient to withstand direct impact by fully-fuelled large-capacity aircraft and ballistic missiles and capable of being policed and defended against all foreseeable forms of terrorist attack.

Uranium
Stocks of separated uranium also represent a national energy resource and should be carefully and securely preserved. However, while uranium is stable in the chemical form of the dioxide, UO2, the hexafluoride is volatile and the trioxide, UO3 (including UO3 hydrates) is somewhat soluble. If long-term storage for periods exceeding 10 - 20 years is contemplated, a consideration should be given to converting the uranium into a stable and relatively insoluble form.

The Hazards and Risks of Radioactive Waste Management

The historical approach to radiological hazard control has been solely anthropocentric in philosophy. Fortunately, the current state of international science in this area is moving towards a hazard control system which is environmentally/ecologically centred, consistent with the United Nations Conference on Environment and Development (UNCED) Agenda 21 concepts of sustainability, biodiversity and the precautionary principle. While it is pleasing to see this trend somewhat acknowledged in the consultation document, it should be noted that major revision of the criteria inherent in limiting environmental releases is necessary. Furthermore, major uncertainties remain in assessing environmental and ecosystem consequences and research in this area is needed.

A Public Debate

Public Acceptability
The sentiments expressed in this paragraph are particularly appropriate. If the general population does not feel a stakeholder in a policy, and a consequent sense of ownership, then the implementation of any such policy will indeed be strongly opposed.

Techniques for Engaging the Public
The emphasis placed on ensuring public involvement in the processes of discussion and decision-making is an important feature of the proposals. All the proposed fora are valuable and should be developed and implemented. Important issues include:

  • the need to avoid an adversarial approach
  • the need to agree on how selection should be achieved to ensure representative groups
  • the need to accept that special local considerations will apply, particularly to communities close to potential/actual disposal sites, so that whatever national exercise is conducted, affected communities may need special local provision.

Whatever form of consultation is decided, the internet can a useful way of obtaining dialogue and promoting involvement for those who have access to it. In parallel, the conventional radiological hazard control procedures should be blended with environmentally/ecologically centred approaches so that the finally applied criteria gain public acceptance.

An important omission from the proposals, however, is its lack of specific involvement of the media in engaging the public. We live in a media-dominated age and the media in all its forms provide the primary means by which the UK public becomes informed. A highly proactive programme aimed at providing public information, stimulating discussion and shaping informed opinion, is essential if public acceptability is to be gained for both any future nuclear industry and the associated radioactive waste disposal strategy.

Another key issue will be the management of the consultative exercise. The exchange of information to and from the consultative groups will need to be developed and conclusions monitored. Experts and reporters may have to be recruited and trained. The exercise will need to be closely supervised and independently monitored if it is to command confidence and deliver the intended results.

Managing the Debate

Given public mistrust of the "nuclear establishment" in the UK, there would be merit in increasing the involvement of the non-establishment component of any management body. It will be important that an augmented RAWMAC, or any new body, should be independent and seen to be so, and not reliant on the nuclear industry for funding. The cost may, therefore, have to be a public charge unless an acceptable "arms length" formula can be found.

Two possible models which have much to commend them are the Research Institute Model and a Nuclear Waste Management Commission. Both can maintain sufficient independence and draw flexibly on the skills of individuals, groups and companies, as required, to discharge their functions. Moreover, they remain clearly linked to Government and ultimately the public. Nevertheless, there will be a continuing requirement for the RWMAC in the short-term, at least until new advisory arrangements were up and running satisfactorily.

Most of the priority goals can be identified from the present state of knowledge, however, for geologic barriers, rock characterisation is essential. Much research is expected to be commissioned by BNFL in 2002, which will focus on UK needs. It will be important to decide how such information will be assimilated and evaluated and how other research programmes will interact with the BNFL programme.

The consultation paper also notes the existence of substantial research strengths in the UK. This is correct, but only from a historic perspective and UK strengths are rapidly being dissipated. Preservation of skills in this area could be valuable and only prompt action will prevent further loss of expertise within the UK. Once lost, such expertise will be difficult and expensive to recreate.

The Programme for Action

Storage of Wastes
Since the publication of the consultative document, a re-appraisal of security of stored uranium, plutonium and "dirty" wastes has been ongoing, with the September 11 terrorism events greatly altering the technical requirements for high-security radioactive waste storage. Revised proposals are needed to address the new challenges, along with a more urgent timescale than that set out in the consultation paper in order to upgrade storage security accordingly.

Regulation
With regard to the regulatory arrangements for radioactive waste management on nuclear sites, a multiplicity of responsible organisations does not further protect the public, but may lead to excessive delay, confusion, dilution of effort and lack of clear-cut lines of authority. The Environment Agency (England and Wales) and Scottish Environment Protection Agency (SEPA)(Scotland) need to co-ordinate with HSE and, where appropriate, the National Radiological Protection Board through Memorandum of Understanding. New powers could be granted to the Environment Agency and SEPA in order to ensure maximum transparency and licensee responsibility but one body (e.g. the Health and Safety Executive) should be responsible for monitoring compliance with the entire site licence.

Additional Information

In responding to this consultation, the Society would like to draw attention to the following Royal Society of Edinburgh publications which are of relevance to this subject: Energy and the Environment (December 1998); New and Renewable Energy (May 1999); Basic Safety Standards Directive Euratom 96/29 (June 1999); Scotland’s National Waste Strategy (July 1999); Study of Environmental Planning (October 1999); Royal Commission Study of Environmental Planning (July 2000); Energy and Natural Environment: A Way To Go (September 2000) and Fuelling the Future (March 2001).

 

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