Glossary

Advanced Gas-cooled Reactor

A term used for the second generation of British Power Reactors, now operated by British Energy. The fuel used in the reactor is slightly enriched uranium oxide clad in stainless steel. The coolant is carbon dioxide and the moderator is graphite. The fuel is manufactured at Springfields and reprocessed at Sellafield.

AGR

Advanced Gas-cooled Reactor.

British Energy

A UK private sector company that operates nuclear power stations.

Committee on Radioactive Waste Management

The Committee on Radioactive Waste Management (CoRWM) is an independent body set up by Government to recommend a strategy for the long-term management of higher activity wastes in the UK. The Committee reported in July 2006. CoRWM has been re-constituted with modified terms of reference and membership to scrutinise the Managing Radioactive Waste Safely (MRWS) programme and its implementation.

Contaminated land

Contaminated land is defined as ground, soil, water and, potentially, underground structural materials such as building foundations which have been impacted by radioactive and/or chemical substances from past or present operations (including authorised discharges and disposals), and for which the level of the radioactive or chemical substance is above natural background.

CoRWM

Committee on Radioactive Waste Management

Decommissioning

The final phase in the life cycle of a nuclear installation covering all activities from shutdown and removal of radioactive material to environmental restoration of the site.

Defra

The UK Government department which, with the environment departments of Wales, Scotland and Northern Ireland, sets policy for UK radioactive waste management.

Disposal

The emplacement of waste in a suitable facility without intent to retrieve it. (Retrieval may be possible but, if intended, the appropriate term is storage.)

GE Healthcare Ltd

Previously Amersham plc. A company that provides products and services for use in healthcare and life science research. This includes radioisotopes for medical and research users.

Geological disposal

Geological disposal usually refers to a long-term management option involving the emplacement of radioactive waste in an engineered repository at between 200 metres and one kilometre underground where the geology (rock structure) provides a barrier against the escape of radioactivity.

Government

A collective term for the central government bodies responsible for setting radioactive waste management policy within the UK. It includes the Houses of Parliament and the Devolved Administrations.

High Level Waste

Wastes in which the temperature may rise significantly as a result of their radioactivity, so this factor has to be taken into account in the design of waste storage or disposal facilities. HLW needs thick concrete walls to shield operators from the high radiation. Initially HLW comprises nitric acid solutions containing the waste products of reprocessing spent nuclear fuels.

HLW

High Level Waste

ILW

Intermediate Level Waste

Intermediate Level Waste

ILW is waste with radioactivity levels exceeding the upper boundaries for LLW but which does not generate enough heat for this to need to be taken into account in the design of storage or disposal facilities. However like other radioactive waste it still needs to be contained to protect workers from radiation. The major components of ILW are metal items such as nuclear fuel casing and nuclear reactor components, graphite from reactor cores, and sludges from the treatment of radioactive liquid effluents.

LLW

Low Level Waste

LLWR

Low Level Waste Repository

LLW Repository Ltd

LLW Repository Limited is currently part of the BNFL group of companies. The NDA initiated a competition process in April 2006 to find a new Parent Body Organisation (PBO) to run the LLWR site, including ownership of the LLW Repository Limited company. This new PBO has a broader remit than the current operators – it will be responsible for the co-ordination of low level waste management activities and any potential new facilities throughout the UK. This process was expected to be completed in 2008.

Low Level Waste

Low Level Waste (LLW) is the lowest activity category of radioactive waste. Overall, the major components of LLW are building rubble, soil and steel items such as framework, pipework and reinforcement from the dismantling and demolition of nuclear reactors and other nuclear facilities and the clean up of nuclear sites. However, at the present time most LLW is from the operation of nuclear facilities, and this is mainly paper, plastics and scrap metal items. A sub-category of LLW is Very Low Level Waste (VLLW).

Low Level Waste Repository

The Low Level Waste Repository (LLWR) near the village of Drigg, south of Sellafield, in Cumbria has operated as a national disposal facility for LLW since 1959.

LWR

Light Water Reactor

m3

Cubic metres – a measure of volume.

Magnox

An alloy of magnesium used for fuel element cladding in natural uranium fuelled gas-cooled power reactors. Also a generic name for this type of reactor.

Magnox Electric Ltd

Magnox Electric Ltd is the Site Licence Company (SLC) that manages the day-to-day operations across two regions of UK reactor sites, Magnox North and Magnox South on behalf of the Nuclear Decommissioning Authority (NDA). Reactor Sites Management Company Ltd, a company wholly owned by EnergySolutions, LLC is the Parent Body Organisation that owns all the shares in Magnox Electric Ltd and provides management expertise for the duration of the contract with the NDA. 

Managing Radioactive Waste Safely

The Managing Radioactive Waste Safely (MRWS) programme was established by the UK Government and the Devolved Administrations for Scotland, Wales and Northern Ireland for developing and implementing a policy for managing the UK’s higher activity wastes in the long-term.

Minor Waste Producers

Organisations that use radioactive materials and create radioactive wastes, and that are not part of the nuclear sector licensed under the Nuclear Installations Act 1965 (as amended), including hospitals, universities and industrial undertakings. These organisations produce small amount of radioactive wastes; most of which can be safely disposed of with domestic, commercial or industrial wastes. The small fraction of these wastes that is subject to specific regulatory controls is managed at the Harwell and Sellafield licensed sites.

MoD

Ministry of Defence

MRWS

Managing Radioactive Waste Safely

MWP

Minor Waste Producers

NDA

Nuclear Decommissioning Authority

Nexia Solutions

A science and technology services company, part of British Nuclear Fuels plc.

Nuclear Decommissioning Authority

A public body set up by the Government in April 2005 with responsibility for the UK's public sector civil nuclear liabilities, and their subsequent management. In October 2006, the Government also gave the NDA the responsibility for developing and ensuring delivery and implementation of the programmes for interim storage and geological disposal of the UK’s higher activity wastes. From March 2007, the NDA was also given responsibility for developing a UK wide strategy for managing the UK nuclear industry’s LLW and for securing disposal capacity for LLW generated by non-nuclear industry users.

Nuclear fuel

Fuel used in a nuclear reactor. Most fuel is made of uranium, and produces heat when the uranium atoms split into smaller fragments.

Operational waste

Wastes arising from the day-to-day operations of a facility associated with the use or handling of radioactive materials.

Plutonium

A radioactive element created in nuclear reactors. It can be separated from spent nuclear fuel by reprocessing. Plutonium is not classified as radioactive waste as it has potential value. It can used as a nuclear fuel, in nuclear weapons and as a power source for space probes.

PWR

Pressurised Water Reactor

Radioactivity

A property possessed by some atoms that split spontaneously, with release of energy through emission of a sub-atomic particle and/or radiation.

Reprocessing

The chemical extraction of reusable uranium and plutonium from waste materials in spent nuclear fuel.

Sellafield Ltd

The company holding the nuclear license (i.e. SLC) to operate Sellafield, Calder Hall, Windscale and Capenhurst (NDA). In October 2006 the NDA announced that the management of Sellafield Ltd would be competed commencing Spring 2007. This process was expected to be completed in 2008.

Site Licence Company

Entity that holds the nuclear site licence and the discharge authorisations for a UK nuclear site for which the NDA is responsible. The SLC carries out the daily management and operations of the site under contract to the NDA.

SLC

Site Licence Company

Spent nuclear fuel

Fuel that has been used to power nuclear reactors that is no longer capable of efficient fission due to the loss of fissile material. These radioactive materials are not classified as wastes as they have potential value. Spent fuel can be reprocessed to separate uranium and plutonium.

Springfields Fuels Ltd

The company holding the nuclear license (i.e. SLC) to operate Springfields. Springfields Fuels Limited was formed in April 2005 as part of the government's reorganisation of the nuclear industry in the UK. Westinghouse Electric UK Ltd is the Management & Operations (M&O) company running Springfields and Springfields Fuels Limited on the NDA's behalf.

Storage

The emplacement of waste in a suitable facility with the intent to retrieve it at a later date.

United Kingdom Atomic Energy Authority

UKAEA is a contractor to the Nuclear Decommissioning Authority (NDA) for management of decommissioning at Dounreay, Harwell, Windscale, Winfrith and the fusion research facilities at Culham. Also in 2005, the Government approved UKAEA's plans to expand and compete for wider business.

UKAEA

United Kingdom Atomic Energy Authority

Uranium

A radioactive element that occurs in nature. Uranium is not classified as a radioactive waste as it has potential value. It can be used to manufacture fresh nuclear fuel and nuclear weapons. 

Urenco

A company that is engaged in uranium enrichment at Capenhurst in Cheshire.

Very Low Level Waste

This comprises small volumes principally from hospitals and universities that can be safely disposed of with municipal, commercial or industrial waste (either directly or after incineration), and larger volumes from nuclear sites that can be disposed of to specified landfill facilities.

VLLW

Very Low Level Waste