The Committee on Radioactive Waste Management

The following are definitions of technical terms often used in radioactive waste management and some other key terms used on this website. A complete glossary of all the technical and other specialist terms used in CoRWM documents is available to download in PDF format (10 pages) (download the CoRWM Glossary).

• Confidentiality
• Disposal
• Geological disposal information
• Near-surface disposal
• Retrievability
• Non-Governmental organisations
• Public and stakeholder engagement
• Site stakeholder groups
• Radioactive waste
• High level waste
• Intermediate level waste
• Higher activity waste
• Spent fuel
• Radioactive waste management
• Regulators
• Research and development
• Safety case
• Storage
• Interim storage information
• Long-term storage
• Treatment, conditioning and packaging
• Treatment
• Conditioning
• Packaging
• Waste package
• Voluntarism and partnership
• Benefits package
• Decision to participate
• Expression of Interest

Confidentiality

CoRWM’s Publication Scheme and Transparency Policy (doc. 2249) explain what information we keep confidential and why. We keep information confidential when asked to do so by others and when it would be illegal for us to publish it. The reasons we might be asked to keep information confidential include national security, commercial considerations and a wish not to release early thinking about possible new Government policy.

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Disposal

In radioactive waste management the term “disposal” is only used to mean placing radioactive waste in an appropriate facility with no intention of retrieving it. Plans for disposal facilities always involve sealing the facilities at some time after they are full, whereas storage facilities are kept open throughout their lifetimes, until the wastes or materials are removed. Other terms used in connection with disposal are:

“geological disposal” – disposal underground at a depth of more than about 200 metres (also called “deep geological disposal”). The depth is chosen so as to provide a barrier against the escape of radioactivity and protect the waste from disturbance. This disposal method is appropriate for high level and intermediate level wastes.

“near-surface disposal” – disposal at the earth’s surface or underground at a depth of at most a few tens of metres. In this method it is the engineered structures (for example concrete vaults) that provide most or all of the protection for the radioactive wastes. Near-surface disposal is only appropriate for low level wastes and those intermediate level wastes that contain only trace amounts of long-lived radioactive materials (half-lives more than 30 years).

“retrievability” – the ability to remove radioactive wastes from a disposal facility that is achieved by designing the facility in an appropriate way. This is distinct from reversibility (the ability to remove wastes by simply reversing the process by which they were emplaced) and recoverability (the ability to remove wastes from a sealed disposal facility by mining, drilling boreholes etc.)

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Non-governmental organisations

The term non-governmental organisation (NGO) literally means any organisation not belonging to or associated with Government. In the context of nuclear energy it is mainly used to mean an organisation that is against the continuation and expansion of nuclear power, and/or other aspects of Government policy on nuclear matters. Greenpeace and Friends of the Earth are two of the largest NGOs.

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Public and stakeholder engagement

CoRWM uses “stakeholder” to mean any person or organisation that has an interest in or is affected by radioactive waste management. This includes waste producers, regulators, NGOs and local authorities and communities near existing nuclear sites and potential disposal sites. We use “public” to mean people who have no particular interest in, and are not affected by, radioactive waste management.

“Public and stakeholder engagement” (PSE) is the term we use for any activity in which people are consulted about, or involved in decision making for, radioactive waste management. The key feature of PSE is that it is a two-way process. Providing information is only a part of PSE and must be followed by some form of communication between those who received the information and those who provided it.

Site stakeholder groups (SSGs) are the main means of engagement for stakeholders local to sites owned by the Nuclear Decommissioning Authority (NDA). They are made up of local residents, including people from local government. They are consulted by the site operator (the Site Licence Company (SLC)) and the NDA about key issues on the site, such as the timing of decommissioning, the state in which the site will be left at the end of decommissioning and the methods of managing major types of radioactive wastes. There is more information about SSGs on the NDA website. Other (non-NDA) nuclear sites have equivalent groups but they have different names (eg Local Liaison Committees).

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Radioactive waste

The legal definition of “radioactive waste” is in the Radioactive Substances Act 1993 and the Environmental Permitting (England and Wales) Regulations 2010. We use the term in this sense throughout our work. The definition is essentially that “radioactive waste” is any substance for which there is no further use and that contains any artificial radioactivity and/or any natural radioactivity above the levels given in Schedule 1 of the Act and the corresponding schedule of the Regulations. This legal definition is under review and it is expected that a revised definition will be put in place in 2010-11.

We do not use the term “nuclear waste” but others do. It means radioactive waste produced by the nuclear industry. Other, non-nuclear, producers of radioactive waste include hospitals, factories and research laboratories. In the UK radioactive waste produced by the Ministry of Defence would usually be included in “nuclear waste”. In the USA this is frequently called “defense waste” and the term “nuclear waste” is reserved for radioactive waste from the civil nuclear industry.

“Radioactive waste” includes solids, liquids and gases, with radioactivity levels ranging from “high” to “very low”. Definitions of the categories of radioactive waste within CoRWM’s remit are:

“high level waste” (HLW) – radioactive waste in which the activity levels are so high that it generates a substantial amount of heat. (The term is only used in the UK for the acidic liquids arising from reprocessing of spent fuels and the solidified forms of these liquids).

“intermediate level waste” (ILW) – radioactive waste which does not generate much heat but which has radioactivity levels above the upper boundaries for low level waste (LLW) (4 Gigabecquerel per tonne alpha activity or 12 Gigabecquerel per tonne beta/gamma activity.

“higher activity waste” (HAW) – high level waste and intermediate level waste.

“Spent fuel”, that is fuel that has been used in a nuclear reactor, plutonium and uranium are not “radioactive waste” until it has been decided that they will not be processed for re-use. Spent fuel, plutonium and uranium are often collectively called “nuclear materials”.

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Radioactive waste management

The term “radioactive waste management” covers all the operations from reducing the amounts of waste produced, through treatment (for example, decontamination), “conditioning”, “packaging” and “storage”, and finally disposal.

The term “long-term radioactive waste management” is used to mean disposal and the conditioning, packaging and interim storage that is necessary before disposal can take place.

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Regulators

We usually use the term “regulators” to mean the main organisations that regulate the safety, security and environmental aspects of the nuclear industry in the UK. These organisations are:

• the Health and Safety Executive (HSE), which contains:
  • the Nuclear Installations Inspectorate (NII), the safety regulator
  • the Office of Civil Nuclear Security (OCNS), the security regulator
  • the UK Safeguards Office (UKSO), the safeguards regulator
• the Environment Agency (EA), which regulates radioactive waste disposal and other environmental matters in England and Wales
• the Scottish Environment Protection Agency (SEPA), which regulates radioactive waste disposal and other environmental matters in Scotland
• the Department for Transport (DfT), whose Radioactive Materials Transport Team (RMTT) regulate the safety of transport by road and rail and whose Transport Security and Contingencies Directorate (TRANSEC) regulate the security of transport of radioactive material (except nuclear materials, the security of which is regulated by OCNS).

The Office for Nuclear Regulation (ONR) is due to come into being in the first half of 2011. It will be an organisation within HSE and will regulate nuclear and conventional safety and security on nuclear sites and the safety and security of the transport of nuclear and other radioactive materials. NII, OCNS, UKSO, RMTT and the relevant parts of TRANSEC will all move into ONR.

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Research and Development

We define “research” as any investigation directed towards the discovery of some fact or principle by scientific enquiry or a course of study. “Development” is use of the knowledge gained from research to produce or improve materials, devices, facilities, systems or methods. Thus “research and development” (R&D) is gaining knowledge and putting it to use.

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Safety Case

The “safety case” for a nuclear facility or operation is the set of arguments that demonstrates that it is or if particular actions are taken, will be safe. It is also used to mean the suite of documents that contains these arguments.

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Storage

In radioactive waste management “storage” always means placing radioactive wastes (or nuclear materials that may be later declared to be wastes) in a facility with the intention of retrieving them at a later date. This is in contrast to “disposal” (see above), where there is no intention to retrieve. Other terms used in connection with storage are:

“interim storage” – storage of radioactive waste prior to the final management step of disposal (also used for nuclear materials to mean storage prior to re-use)

“long-term storage” – storage for more than about 100 years.

Treatment, Conditioning and Packaging

“Treatment” means any process used to make radioactive wastes suitable for the next step in their management. Treatment process include sorting, decontamination, volume reduction and all types of “conditioning”.

“Conditioning” means any process used to prepare radioactive waste for long-term storage and/or disposal. Conditioning methods include incorporating wastes into cement and converting liquids to glasses (vitrification).

“Packaging” means placing radioactive waste into a container for long-term storage and/or disposal. It is also used to cover putting wastes into containers for transport. (Some containers are suitable for storage, transport and disposal. In other cases a separate outer container is used for transport and is removed for disposal.)

“Waste package” is the term used for a radioactive waste container and all its contents.

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Voluntarism and Partnership

The current approach to siting a geological disposal facility in the UK is described as “voluntarism and partnership”. It is voluntarist because it involves communities voluntarily expressing an interest in holding discussions with Government about hosting a facility, then deciding whether to participate further. When a community has decided to take matters further it is envisaged that it will work in partnership with Local Authorities, other near-by communities, the Nuclear Decommissioning Authority and other relevant parties during site investigations.

Other terms that are used in connection with the siting process are as follows.

“Benefits Package” – the set of measures to enhance the social and economic well-being of a community that hosts a geological disposal facility. This is in recognition that the community is performing an essential service for the country. Also called “Community Benefits Package”.

“Decision to Participate” – a decision by a community to participate in the geological disposal facility siting process, without commitment to eventually host a facility.

“Expression of Interest” – a notification to Government that a community is interested in entering discussions about involvement in the geological disposal facility siting process, without commitment.

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