The Scottish Environment Statistics - 1998

7. RADIOACTIVITY

Table 7.4 Environmental monitoring by operator - atmospheric discharges, 1988-1995 Site Material Nature of radioactivity Location Annual mean concentrations 1988 1989 1990 1991 1992 1993 1994 1995 Chapelcross Milk1 Tritium Inner farms 370 <300 <310 <310 <250 <140 130 110 Outer farms <320 <300 <320 <300 <240 <90 <90 70 Carbon 14 Inner farms 48 48 68 12 11 12 12 21 Outer farms 33 55 68 12 11 12 12 21 Sulphur 35 Inner farms <1.4 <1.6 1.8 0.61 1.8 1.2 2.3 1.3 Outer farms <1.4 <1.9 <2.0 0.7 2.5 1.4 2.3 1.2 Strontium 90 Inner farms 0.04 0.03 0.06 0.02 0.06 0.06 0.07 0.06 Outer farms 0.04 0.04 0.05 0.01 0.06 0.05 0.06 0.07 Caesium 1342 Inner farms nd nd na na na na na na Outer farms nd nd na na na na na na Caesium 137 Inner farms 0.27 0.26 0.10 0.09 0.03 0.05 0.06 0.05 Outer farms 0.62 0.18 0.09 0.09 0.04 0.04 0.05 0.05 Green vegetables3 Tritium Near farms 800 4,100 2,200 700 14,6005 370 3,800 890 Remote farms 850 600 1,650 60 460 5.5 8 9.3 Carbon 146 Near farms 74.0 10.0 6.0 3.2 2.8 6.4 6.6 9.5 Remote farms <110 7 5 3 3 6.1 6.2 8.8 Strontium 90 Near farms 0.20 0.60 <0.10 0.50 0.5 0.65 1.3 1.3 Remote farms 0.10 0.20 <0.10 0.10 0.15 0.15 0.15 0.25 Dounreay Milk1 Strontium 90 Inner farms 0.22 0.24 0.20 na na na na na Outer farms 0.24 0.19 0.40 0.40 0.5 0.48 0.7 0.65 Iodine 129 Inner farms na na na na na na na na Outer farms na na na na <0.20 <0.20 <0.20 <0.20 Iodine 131 Inner farms <0.30 <0.30 <0.30 na na na na na Outer farms <0.30 <0.30 <0.30 <0.30 <0.30 <0.30 <0.30 <0.30 Caesium 1342 Inner farms na na na na na na na na Outer farms <1.5 na <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 Caesium 137 Inner farms <5.8 <3.2 <1.0 na na na na na Outer farms <5.5 <1.2 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 Hunterston Milk1 Sulphur 35 0.46 0.81 0.43 0.26 <0.46 <0.98 <0.10 1.2 Strontium 89 nd nd nd nd nd na na na Strontium 90 0.10 0.14 0.10 0.07 0.07 na na na Iodine 131 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 <0.5 <0.5 Caesium 1342 na na na na na na na na Caesium 1374 1.30 0.94 0.81 0.85 0.62 0.4 0.35 0.35 Torness Milk1 Sulphur 35 <1.0 <1.0 <1.0 <1.0 <1.0 <0.3 <0.1 <0.3 Strontium 89 0.03 <0.11 na na 0.14 <0.07 <0.03 <0.03 Strontium 90 0.07 0.09 0.19 0.14 0.18 0.30 <0.04 <0.18 Iodine 131 <0.40 <0.40 <0.40 <0.40 <0.40 <0.03 <0.01 <0.03 Caesium 134 <0.15 <0.15 <0.16 <0.23 <0.23 <0.22 0.04 <0.25 Caesium 137 <0.25 <0.25 <0.22 <0.26 <0.35 <0.39 <0.15 <0.41 Source: HM Industrial Pollution Insectorate nd: not detected na: not analysed 1 Becquerels per litre. 2 Caesium 134 is not analysed as part of the statutory programme and the results given are based on special measurements undertaken as part of the Chernobyl monitoring for years up to 1987. 3 Becquerels per kilogram (fresh weight) 4 Includes any caesium 134 present from 1987 onwards. 5 Results takes into account extra readings in third quarter. 6 Results since 1994 have been corrected for natural background concentrations of carbon 14.