Radioactivity in Food and the Environment, 2002
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RIFE - 8 Radioactivity in Food and the Environment, 2002 2003 ENVIRONMENT AGENCY ENVIRONMENT AND HERITAGE SERVICE FOOD STANDARDS AGENCY SCOTTISH ENVIRONMENT PROTECTION AGENCY Radioactivity in Food and the Environment, 2002 RIFE - 8 October 2003 1 This report was compiled by the Centre for Environment, Fisheries and Aquaculture Science on behalf of the Environment Agency, Environment and Heritage Service, Food Standards Agency and the Scottish Environment Protection Agency. © Crown Copyright, 2003 Requests for the reproduction of materials contained in this report and for other information should be addressed to: • In England and Wales, Radiological Monitoring and Assessment, Monitoring and Assessment Process Group of the Environment Agency ([email protected]) or the Radiological Protection and Research Management Division of the Food Standards Agency ([email protected]) • In Scotland, the Radioactive Substances Unit of SEPA ([email protected]) and • In Northern Ireland, the Industrial Pollution and Radiochemical Inspectorate of EHS ([email protected]) 2 FOREWORD We are pleased to present the 8th annual Radioactivity in Food and the Environment (RIFE) report, which contains radiological monitoring data for 2002. This report is a major step forward in the reporting of radiological monitoring. For the first time, the RIFE report contains data from monitoring of food and the environment throughout the UK. This work is a collaboration among four Agencies: the Food Standards Agency, the Scottish Environment Protection Agency, the Environment Agency and the Environment and Heritage Service of Northern Ireland. The collaboration enables the Agencies to present a better assessment of the overall impact of radioactive discharges on food safety and the environment. The partnership also shows the commitment of the Agencies to provide a comprehensive report of monitoring data and their intention to work closely together to ensure protection of the public. The report shows that in 2002 radiation doses to the public resulting from radioactive discharges to the environment were well below national and international limits in all parts of the UK. An essential part of assessing the impact of radiological discharges is the estimation of dose to the public. We are pleased to note that significant progress is being made on an improved method of calculating doses. The improved methodology takes account of all public exposure routes in a realistic way, leading to an improved and more reliable assessment of dose to the public from discharges to the environment. The development of this new method is being overseen by a national body, the National Dose Assessment Working Group, whose membership includes consumer representatives, officials from the Agencies, Government and the nuclear industry. We look forward to presenting assessments of doses to the public using the new method in future editions of RIFE. We hope you will find this new format of report comprehensive and informative and we would like to take this opportunity to thank you for interest in the work of our Agencies. Sir John Harman Mr Ken Ledgerwood Chairman, Environment Agency Chief Industrial Pollution and Radiochemical Inspector, Environment and Heritage Service for Northern Ireland Professor Sir John Krebs Sir Ken Collins Chairman, Food Standards Agency Chairman, Scottish Environment Protection Agency 3 4 CONTENTS Page LIST OF TABLES ...................................................................................................................................... 7 EXECUTIVE SUMMARY ............................................................................................................................ 9 1. Introduction ................................................................................................................................. 15 1.1 Background ........................................................................................................................... 15 1.2 Disposals of radioactive waste.............................................................................................. 16 1.2.1 Radioactive waste disposal from nuclear sites.......................................................... 16 1.2.2 Radioactive waste disposal at sea ............................................................................. 18 1.2.3 Other sources of radioactivity ................................................................................... 19 1.2.4 Food irradiation ......................................................................................................... 19 2. Sampling and measurement ......................................................................................................... 21 2.1 Sampling programme ............................................................................................................ 21 2.1.1 Nuclear sites ..............................................................................................................21 2.1.2 Industrial and landfill sites ........................................................................................ 23 2.1.3 Chernobyl fallout....................................................................................................... 24 2.1.4 Additional monitoring ............................................................................................... 24 2.2 Methods of measurement ...................................................................................................... 26 2.2.1 Sample analysis ......................................................................................................... 26 2.2.2 Measurement of dose rates and contamination ......................................................... 27 3. Presentation and assessment ........................................................................................................ 31 3.1 Temporal averaging of monitoring data................................................................................ 31 3.2 Spatial averaging of monitoring data .................................................................................... 31 3.3 Detection limits ..................................................................................................................... 32 3.4 Additional information ......................................................................................................... 32 3.5 Radiation protection standards ............................................................................................. 32 3.6 Assessment methods and data............................................................................................... 34 3.6.1 Radionuclide concentrations in foodstuffs, drinking water, sediments and air ........ 34 3.6.2 Consumption, drinking and inhalation rates ............................................................. 35 3.6.3 Dose coefficients ....................................................................................................... 36 3.6.4 External exposure ...................................................................................................... 37 3.6.5 Subtraction of ‘background’ levels ........................................................................... 37 3.6.6 Summation of doses from different pathways .......................................................... 38 3.6.7 Uncertainties in dose assessment .............................................................................. 38 4. British Nuclear Fuels plc .............................................................................................................. 39 4.1 Sellafield, Cumbria ............................................................................................................... 39 4.1.1 The aquatic monitoring programme .......................................................................... 39 4.1.2 The terrestrial monitoring programme ...................................................................... 52 4.2 Drigg, Cumbria ..................................................................................................................... 54 4.3 Springfields, Lancashire ....................................................................................................... 55 4.4 Capenhurst, Cheshire ............................................................................................................ 56 4.5 Chapelcross, Dumfries and Galloway .................................................................................. 57 5. United Kingdom Atomic Energy Authority ............................................................................... 91 5.1 Dounreay, Highland .............................................................................................................. 91 5.2 Harwell, Oxfordshire ............................................................................................................ 93 5.3 Winfrith, Dorset .................................................................................................................... 94 5.4 Culham, Oxfordshire............................................................................................................. 94 6. Nuclear power stations operated by electricity generating companies ................................. 101 6.1 Berkeley, Gloucestershire and Oldbury, South Gloucestershire ........................................ 101 6.2 Bradwell, Essex..................................................................................................................