Cefas contract report C7325 Radiological Habits Survey: Hinkley Point, 2017 2018 Environment Report RL 09/18 This page has been intentionally left blank Environment Report RL 09/18 Radiological Habits Survey: Hinkley Point, 2017 B.J. Greenhill, F.J. Clyne, A. Milligan and A. Neish 2018 The work described in this report was carried out under contract to the Environment Agency, the Food Standards Agency and the Office for Nuclear Regulation. Cefas contract C7325 FSA Project FS131008 Cefas Document Control Radiological Habits Survey: Hinkley Point, 2017 Environment Agency, Food Standards Agency and Office for Nuclear Submitted to: Regulation Date submitted: 13/04/2018 Project Manager: Victoria Ly Report compiled by: Billy Greenhill Quality control by: Neil Edwards Approved by & date: Fiona Clyne 13/04/2018 Version: Final Version Control History Author Date Comment Version Sent to FSA, EA and Billy Greenhill 28/12/2017 Draft 1 ONR for comment Revised and sent to Billy Greenhill 09/03/2018 FSA, EA and ONR for Draft 2 comment All amendments Billy Greenhill 13/04/2018 Final completed This report should be cited as: Greenhill, B.J., Clyne, F.J., Milligan, A., and Neish, A., 2018. Radiological Habits Survey: Hinkley Point, 2017. RL 09/18. Cefas, Lowestoft A copy can be obtained by downloading from the Cefas website: www.cefas.co.uk © Crown copyright, 2018 Page 2 of 76 Radiological Habits Survey: Hinkley Point, 2017 CONTENTS KEY POINTS .......................................................................................................................................... 7 SUMMARY .............................................................................................................................................. 9 1 INTRODUCTION ........................................................................................................................... 16 1.1 Regulatory framework ........................................................................................................... 16 1.2 Radiological protection framework ........................................................................................ 17 2 THE SURVEY ............................................................................................................................... 19 2.1 Site activity ............................................................................................................................ 19 2.2 Survey objectives .................................................................................................................. 19 2.3 Survey areas ......................................................................................................................... 20 Figure 1. The Hinkley Point aquatic survey area .......................................................................... 22 Figure 2. The Hinkley Point terrestrial and direct radiation survey areas. .................................... 23 2.4 Conduct of the survey ........................................................................................................... 24 3 METHODS FOR DATA ANALYSIS ............................................................................................. 26 3.1 Data recording and presentation ........................................................................................... 26 3.2 Data conversion .................................................................................................................... 26 3.3 Rounding and grouping of data ............................................................................................. 27 Table A. Names of age groups and range of ages within each age group. .................................. 27 3.4 Approaches for the identification of high rates ...................................................................... 28 3.5 Profiles of habits survey data for use in total dose assessments ......................................... 29 3.6 Data quality ........................................................................................................................... 29 4 AQUATIC RADIATION PATHWAYS ........................................................................................... 31 4.1 Aquatic survey area .............................................................................................................. 31 Figure 3. Brean ............................................................................................................................. 32 Figure 4. Burnham-on-Sea ............................................................................................................ 32 Figure 5. River Brue ....................................................................................................................... 33 Figure 6. Stolford .......................................................................................................................... 35 Figure 7. Doniford ......................................................................................................................... 36 Figure 8. Watchet ........................................................................................................................... 37 Figure 9. Blue Anchor .................................................................................................................... 38 4.2 Commercial fisheries ............................................................................................................. 38 4.3 Destination of seafood originating from the aquatic survey area .......................................... 39 4.4 Hobby fishing, angling and non-commercial shellfish collection ........................................... 39 4.5 Wildfowling ............................................................................................................................ 39 4.6 Other pathways ..................................................................................................................... 40 4.7 Food consumption data ......................................................................................................... 40 Table B. Summary of adults’ consumption rates of foods from the aquatic survey area .............. 41 4.8 Intertidal occupancy .............................................................................................................. 42 Table D. Summary of adults’ intertidal occupancy rates .............................................................. 43 Table E. Summary of children’s and infants’ intertidal occupancy rates ...................................... 44 4.9 Gamma dose rate measurements......................................................................................... 45 Table F. Summary of gamma dose rate measurements taken over intertidal substrates ............ 45 4.10 Handling of fishing gear and sediment .................................................................................. 45 Table G. Summary of adults’ handling rates of fishing gear and sediment .................................. 46 4.11 Water based activities ........................................................................................................... 46 5 TERRESTRIAL RADIATION PATHWAYS .................................................................................. 48 5.1 Terrestrial survey area .......................................................................................................... 48 5.2 Destination of food originating from the terrestrial survey area ............................................ 49 5.3 The potential transfer of contamination off-site by wildlife .................................................... 49 5.4 Food consumption data ......................................................................................................... 50 Table H. Summary of adults’ consumption rates of foods from the terrestrial survey area ........... 51 Page 3 of 76 CONTENTS Table I. Summary of children’s and infants’ consumption rates of foods from the terrestrial survey area .................................................................................................................................... 52 6 DIRECT RADIATION PATHWAYS .............................................................................................. 53 6.1 Direct radiation survey area .................................................................................................. 53 6.2 Residential activities .............................................................................................................. 53 6.3 Leisure activities .................................................................................................................... 54 6.4 Commercial activities ............................................................................................................ 54 6.5 Occupancy rates ................................................................................................................... 54 Table J. Summary of direct radiation occupancy rates ................................................................. 55 6.6 Gamma dose rate measurements......................................................................................... 55 Table K. Summary of gamma dose rate measurements taken indoors and outdoors at properties in the direct radiation survey area ................................................................................ 56 7 USES OF HABITS DATA FOR DOSE ASSESSMENTS ............................................................