Radioactive substances glossary

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A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 

Term Definition
ALARA – As low as reasonably achievable All reasonable steps have been taken to protect people. Costs are weighed against benefits, including the reduction in risks to people and the environment.
Alpha radiation This term refers to ejected radiation from a decaying (radioactive) atom, in the form of particles (helium nuclei). Alpha particles cause ionisations in biological tissue, which may lead to damage.
Annual dose constraint There is a restriction on the annual dose an individual should experience from a single source of radiation. The dose is 0.3 millisieverts (mSv) and it is applied at the design and planning stage of any development, to ensure that when it is combined with doses from all other sources, human health and the environment remain safe.
Authorisation This is a licence granted by SEPA for the disposal and/or accumulation of radioactive waste under Section 13 and/or 14 of the Radioactive Substances Act 1993.
BAT – Best available techniques This refers to using the best techniques possible to reduce discharges of non-radioactive pollutants under Integrated Pollution Control (IPC) regulations.
Becquerel (Bq) This is the standard international unit of radioactivity equal to one radioactive disintegration per second. Multiples of Bq commonly used are:
  • kilobecquerels (kBq) equal to one thousand;
  • megabecquerels (MBq) equal to one million;
  • gigabecquerels (GBq) equal to one thousand million.
Beta radiation This term refers to the form of particles (electrons) emitted from the nucleus of a decaying (radioactive) atom. Beta particles cause ionisations in biological tissue, which may lead to damage.
Beta/gamma radiation Beta radiation is usually accompanied by the emission of gamma rays, hence the term beta/gamma activity.
British Nuclear Group Previous owners of the nuclear fuel reprocessing facility at Sellafield, the Low Level Waste disposal site near to Drigg, the fuel fabrication plant at Capenhurst and Springfields, and the Magnox nuclear power plants. All British Nuclear Group sites are now owned by the Nuclear Decommissioning Authority.
BPEO – Best practicable environmental option This is the outcome of a systematic and consultative decision-making procedure. It provides the most benefit or least damage to the environment as a whole, at an acceptable cost in both the long and short term.
BPM – Best practicable means Operators are required to take all reasonable measures in the design and operational management of their facilities, in order to minimise discharges and disposal of radioactive waste, and to achieve a high standard of protection for the public and the environment. BPM takes account of availability, costs, operator safety and the benefits of reduced discharges and disposals.
CEFAS – Centre for Environment, Fisheries and Aquaculture Services CEFAS is a scientific research and advisory centre working in fisheries management, environmental protection and aquaculture. It is an executive agency of the UK Government's Department for Environment, Food and Rural Affairs (Defra).
Clean-up In the case of radioactive substances, this means the decontamination and decommissioning of a nuclear licensed site.
CoMARE – Committee on Medical Aspects of Radiation in the Environment The committee offers independent advice to all government departments and devolved authorities. It is responsible for assessing and advising them on the health effects of natural and man-made radiation.
Condition A specific restriction or requirement placed on an operator and contained in an authorisation granted by one of the environment agencies.
CoRWM – Committee on Radioactive Waste Management The committee has reviewed the UK's options to manage solid waste for which no long term strategy already exists. CoRWM made its recommendations to the UK Government and devolved administrations during 2006.
Decommissioning The process whereby a nuclear facility, at the end of its economic life, is taken permanently out of service and its site made available for other purposes.
DEFRA ­– Department for Environment, Food and Rural Affairs Defra is a UK Government department.  Its mission is to enable everyone to live within our environmental means. This is most clearly exemplified by the need to tackle climate change internationally, through domestic action to reduce greenhouse gas emissions, and to secure a healthy and diverse natural environment.
Devolved administrations A collective term for the Scottish Executive, Welsh Assembly Government and (in Northern Ireland) the Department of the Environment.
Discharge The release of aerial or liquid waste to the environment.
Disposal The release of airborne or liquid waste to the environment, or the placing of solid waste in a suitable facility without the intent to retrieve.
Dose A general term used as the radioactive measure absorbed by a human. The dose is measured in sieverts, and its sub-multiples [ie millisieverts (mSv), equal to one thousandth of a sievert].
DPAG – Dounreay Particles Advisory Group DPAG provides impartial expert scientific advice on the current UK Atomic Energy Authority's research program in respect of particles in the Dounreay local environment.  The group's main objective is to make recommendations to SEPA (and to UKAEA) about ways to improve the monitoring and research programmes for particles in local sediments.
Drigg The facility for the near-surface disposal of most of the UK's solid low level waste, operated by British Nuclear Group (Sellafield) Ltd near the company's Sellafield site in Cumbria.
DYLLWF – Dounreay Low Level Waste Facility This proposed facility near the Dounreay site, is where low level waste from Dounreay and Vulcan will be disposed to. Low level waste is currently stored on site, although the decommissioning process will produce more.
EA – Environment Agency The environmental regulator for England and Wales.
FOI – Freedom of Information The Freedom of Information Act gives everyone the right to access information held by Scottish public authorities. This means anyone can make requests for information to SEPA under FOI.
FSA – Food Standards Agency Independent government department tasked with protecting the public's health and consumer interests in relation to food.
Gamma radiation An electromagnetic radiation similar (in some respects) to visible light, but with higher energy. Gamma rays cause ionisations in biological tissue, which may lead to damage.
GRA – Guidance on requirements for authorisation A document outlining safety standards for the disposal of low and intermediate level waste at land-based disposal facilities.
HASS – High activity sealed source A sealed radioactive source containing a radionuclide whose activity at the time of manufacture exceeds the certain activity levels and has the potential to cause harm.
HLW – High Level Waste Radioactive 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 storage or disposal facilities.
HPA – Health Protection Agency A UK-wide non-Departmental Public Body that protects the health and wellbeing of the population. The Radiation Protection Division was formerly the National Radiological Protection Board.
HSE – Health and Safety Executive A statutory body whose role is the enforcement of work related health and safety law under the general direction of the Health and Safety Commission.
IAEA – International Atomic Energy Authority It was set up as the world's "Atoms for Peace" organisation in 1957. The agency works with its Member States and multiple partners worldwide to promote safe, secure and peaceful nuclear technologies.
ICRP – International Commission on Radiological Protection An advisory body providing recommendations and guidance on radiation protection.
ILW – Intermediate level waste Radioactive wastes exceeding the upper activity boundaries for LLW but which do not need heat to be taken into account in the design of storage or disposal facilities.
Ionisation When radiation interacts with matter, it can cause atoms and molecules to become unstable, creating ions. This process is called ionisation.
ISOLUS – Interim Storage of Laid Up Submarines This is a project established by MoD in 2000 to determine the means of managing low and intermediate level waste, and other waste materials, from nuclear submarines which have left naval service until a final disposal route is available.
Landfill The disposal of waste by shallow burial.
Licensee The company/individual who is responsible for operating a UK nuclear industry facility under the terms and conditions of the site licence.
LLW – low level waste Lightly contaminated miscellaneous scrap, including metals, soil, building rubble, paper towels, clothing and laboratory equipment.
mSv – millisievert Sievert is the unit used to measure the radioactive does absorbed by a human. One mSv is equal to one thousandth of a sievert.
MoD – Ministry of Defence MoD sites that produce radioactive waste are mainly those producing and handling nuclear fuel for submarines and those producing and handling radioactive materials for nuclear weapons.
MRWS – managing radioactive waste safely This phrase refers to the identification and implementation of options for the long term management of the UK's high activity radioactivity waste.
NAIR – National arrangements for Incidents involving radioactivity NAIR was set up to protect the public from hazards that may arise from the use and transport of radioactive materials, and in situations where no formal contingency plans exist.
NDA – Nuclear Decommissioning Authority The NDA is a non departmental public body with designated responsibility for managing the liabilities at specific sites.
NII –The Nuclear Installations Inspectorate Part of the Health and Safety Executive, the NII regulates civil nuclear plant safety in relation to the public and nuclear workers.
NLS – Nuclear licensed site The classification of all civil sites handling nuclear materials, ie all nuclear power stations, nuclear fuel production and reprocessing sites, sites undertaking storage of and/or research into, nuclear materials, and major plant producing radioisotopes. All major nuclear sites must be licensed by the Nuclear Installations Inspectorate (part of the Health and Safety Executive).
Non-nuclear industry waste A general term for the radioactive wastes produced by industries and organisations not involved with the production of nuclear energy or nuclear weapons.
Non-nuclear site A site (eg hospital or university) authorised by SEPA to keep, use or handle radioactive materials, that is not licensed by the Nuclear Installations Inspectorate.
Nuclear waste A general term for the radioactive waste produced by industries involved with nuclear production and large-scale radioisotope production. It includes low, intermediate and high level waste.
Optimisation This is the process for ensuring that all radiation exposures of the public are as low as reasonably achievable (ALARA). Optimisation is achieved by employing best practicable means. Optimisation, justification and limitation are the three key principles of radiation protection which form the basis of European Community and UK legislation.
Proximity principle This means to enable waste to be disposed of in one of the nearest appropriate installations.
Radioactive decay The process by which a radionuclide undergoes transformation, with the emission of radiation.
Radioactive half-life The time it takes for one-half of the atoms of radionuclide to undergo radioactive decay. Each radionuclide has a unique half-life, and half lives vary from fractions of a second through to many millions of years.
Radioactively contaminated land Land that is contaminated with radioactivity from past practices or work activities, or from the after-effects of radiological incidents.
Radioactive waste Any material contaminated by or incorporating radioactivity above certain thresholds defined in legislation, and for which no further use is envisaged.
Radiological risk The probability of someone suffering a serious health effect as a result of the presence of a radioactive source.
Radionuclide Different radioactive forms of the same element, for example caesium-134 and caesium-137 are both radionuclides of the element caesium.
Registration A licence issued by SEPA for the keeping and use of radioactive sources under Section 7 or 10 of the Radioactive Substances Act 1993.
Regulators In the context of radioactive substances; those bodies responsible for the regulation of the nuclear industry and non-nuclear industry low level waste producers.
RIFE – Radioactivity in Food and the Environment An annual report that we produce.
RSA 93 – The Radioactive Substances Act 1993 The legislation under which SEPA regulates the keeping and use of radioactive materials and the accumulation and disposal of radioactive wastes in Scotland.
RWMAC – Radioactive Waste Management Advisory Committee The committee offers independent advice to Ministers on radioactive waste management issues. Members were drawn from a wide range of backgrounds including radioactive waste management, radiological protection, earth sciences, environmental law and planning, medical physics and social sciences.
RWPG – Radioactive Waste Policy Group UA group consisting of UK government departments, the devolved administrations, the Nuclear Decommissioning Authority and the principal regulatory bodies. It considers radioactive waste management policy and the arrangements for its delivery.
SNIFFER – Scottish and Northern Ireland Forum for Environmental Research NA body that identifies advice and research on behalf of Scottish and Northern Ireland government and regulatory bodies.
Sellafield The Nuclear Decommissioning Authority owns the nuclear-licensed site in West Cumbria, comprising of nuclear fuel storage, reprocessing and manufacturing facilities. Sellafield is currently operated by British Nuclear Group Sellafield Ltd.
SNNILG – Scottish Non Nuclear Industries Liaison Group A SEPA run group of non-nuclear industry representatives that meets approximately every six months.
Stakeholders A group of people or organisations < that have a particular knowledge of, or interest in, radioactive substances and who we invite to participate in discussions.
Storage The placing of waste in a suitable facility, with the intention of being retrieved at a later date.
UKAEA – United KingdomAtomic Energy Authority is a non-departmental public body The United Kingdom Atomic Energy Authority (UKAEA) was formed in 1954 when the Government set up a new body to oversee the nation's nuclear research programme. UKAEA's role was to provide Britain's atomic weapons deterrent and develop reactor technologies for the nuclear power stations of the future. It is now a world leader in nuclear clean-up and fusion research.