Risø-R-Report. DTU Nutech Report. Radioactivity in the Risø District July- December 2012

Transcription

1 Risø-R-Report DTU Nutech Report Radioactivity in the Risø District July- December 2012 Sven P. Nielsen, Kasper G. Andersson and Arne Miller DTU-Nutech-R-0005(EN) June 2013

2 Author: Sven P. Nielsen, Kasper G. Andersson and Arne Miller Title: Radioactivity in the Risø District July-December 2012 Division: Radiation Research DTU-Nutech-R-0005(EN) June 2013 Abstract (max char.): The environmental surveillance of the Risø environment was continued in July - December The mean concentrations in air were: Bq m 3 of 137 Cs, mbq m 3 of 7 Be and mbq m 3 of 210 Pb ( 1 S.D.; N = 26). The depositions by precipitation at Risø in the second half of 2012 were: Bq m 2 of 137 Cs, 615 Bq m 2 of 7 Be, 40.3 Bq m 2 of 210 Pb and < 0.6 kbq m 2 of 3 H. The average background dose rate (TLD) at Risø (Zone I) was 54 nsv h 1 compared with 58 8 nsv h 1 ( 1 S.D.; N = 3) in the four zones around Risø. ISBN: Contract no.: Group's own reg. no.: E-1 Sponsorship: Cover : Pages: 24 Tables: 14 References: Center for Nuclear Technologies Technical University of Denmark P.O.Box 49 DK-4000 Roskilde Denmark Telephone

3 Contents Table 1. Radionuclides in air 5 Table 2.1. Radionuclides in precipitation 6 Table 2.2. Radionuclides in precipitation 6 Table 2.3. Tritium in precipitation 7 Table 2.4. Tritium in precipitation 7 Table 3.1. Radionuclides in sediment samples 8 Table 4.1. Radionuclides in seawater 8 Table 4.2. Tritium in seawater 8 Table 5.1. Radionuclides in grass 9 Table 5.2. Radionuclides in sea plants 10 Table 7.1. Waste water 11 Table 8.1. Background dose rates around the border of Risø (TLD) 12 Table 8.2. Background dose rates around Risø (TLD) 13 Table 8.3. Terrestrial dose rates at the Risø zones (NaI(Tl) detector) 14 Fig. 1. Map of Risø 15 Fig Caesium-137 in air 16 Fig Beryllium-7 and lead-210 in air 16 Fig Tritium in precipitation (1 m 2 rain collector) 17 Fig Tritium in precipitation (10 m 2 rain collector) 17 Fig. 3.1 Caesium-137 in sediment samples 18 Fig. 4.1 Caesium-137 in seawater 19 Fig. 4.2 Tritium in seawater 19 Fig. 7.1 Total-beta radioactivity in waste water 20 Fig Map of Risø with locations for TLD measurements 21 Fig The environment of Risø 22 DTU-Nutech-R-0005(EN) 3

4 4 DTU-Nutech-R-0005(EN)

5 Table 1. Radionuclides in ground level air collected at Risø (cf. Figs. 1, 1.1 and 1.2), July - December (Unit: Bq m 3 ) Date 7 Be 137 Cs 210 Pb 02-Jul Jul Jul Jul Jul Jul Jul Jul Jul Aug Aug Aug Aug Aug Aug Aug Aug Aug Sep Sep Sep Sep Sep Sep Sep Oct Oct Oct Oct Oct Oct Oct Oct Oct Oct Nov Nov Nov Nov Nov Nov Nov Nov Dec Dec Dec Dec Dec Dec Dec Dec Dec Mean SD DTU-Nutech-R-0005(EN) 5

6 Table 2.1. Radionuclides in precipitation in the 10 m 2 rain collector at Risø (cf. Fig. 1), July - December (Unit: Bq m 3 ) Month 7 Be 137 Cs 210 Pb July August September October November December Table 2.2. Radionuclides in precipitation in the 10 m 2 rain collector at Risø (cf. Fig. 1), July - December (Unit: Bq m 2 ) Month Precipitation (m) 7 Be 137 Cs 210 Pb July August September October November December Sum DTU-Nutech-R-0005(EN)

7 Table 2.3. Tritium in precipitation collected at Risø (cf. Figs. 1, and 2.3.2). July - December (Unit: kbq m 3 ) Month 10 m 2 rain collector* July 2.2 August < 1.7 September < 1.7 October < 1.7 November < 1.7 December < 1.7 Double determinations*. Table 2.4. Tritium in precipitation collected at Risø (cf. Fig. 1). July - December (Unit: kbq m 2 ) Month Precipitation (m) 10 m 2 rain collector July August < September < October < November < December < Sum < DTU-Nutech-R-0005(EN) 7

8 Table 3.1. Radionuclides in sediment samples collected at Bolund in Roskilde Fjord.(cf. Fig. 3.1) July - December (Unit: Bq kg 1 dry) Date 137 Cs K* 1 July *Unit: g kg -1 dry Table 4.1. Radionuclides in seawater collected in Roskilde Fjord (cf. Fig. 4.1) July - December (Unit: Bq m 3 ) Date 137 Cs 1 July 10.9 Table 4.2. Tritium in seawater collected in Roskilde Fjord (Risø pier) (cf. Fig. 4.2) July - December Month kbq m 3 July < 1.7 * August < 1.7 * September 1.7 * October # - November # - December < 1.7 * * Double determinations # starting autumn 2012, tritium in seawater is measured quarterly. 8 DTU-Nutech-R-0005(EN)

9 Table 5.1. Radionuclides in grass (* snow) collected at Risø (near the Waste Treatment Station (cf. Fig. 1)), July - December (**Measured on bulked ash samples) 137 Cs 137 Cs Week no. K Date or month (g kg 1 fresh) (Bq kg 1 fresh) (Bq m 2 ) 27 2 July 5.0 < July 5.3 < July 4.8 < August 9.9 < August 3.9 < September 6.4 < September 5.7 < October 5.5 < October 4.7 < November 4.4 < November 2.8 < December * < 0.1 < December * < 0.1 <0.2 **July **August **September **October **November **December DTU-Nutech-R-0005(EN) 9

10 Table 5.2. Radionuclides in Fucus vesiculosus collected at Bolund in Roskilde Fjord. July - December (Unit: Bq kg 1 dry) Date 137 Cs K* % dry matter 1 July *Unit: g kg -1 dry 10 DTU-Nutech-R-0005(EN)

11 Table 7.1. Waste water collected at Risø (cf. Fig. 1), July - December Week number eqv. mg KCl l Cs (Bq m 3 ) 131 I (Bq m 3 ) 226 Ra (Bq m 3 ) < 72 < 71 < < 109 < 108 < < 105 < 110 < < 106 < 109 < < 111 < 116 < < 115 < 116 < < 111 < 114 < < 101 < 110 < < 111 < 110 < < 107 < 111 < < 111 < 113 < < 99 < 106 < < 106 < 115 < < 74 < 175 < < 110 < 109 < < 116 < 118 < < 100 < 106 < < 110 < 113 < < 122 < 120 < < 107 < 107 < < 103 < 112 < < 112 < 113 < < 116 < 115 < < 101 < 114 < < 107 < 109 < < 83 < 175 < 239 Mean SD 34.8 DTU-Nutech-R-0005(EN) 11

12 Table 8.1. Background dose rates around the border of Risø (cf. Fig. 8.1) measured with thermoluminescence dosimeters (TLD) in the period May - October (Results are normalized to nsv h 1 ) Location nsv h Mean DTU-Nutech-R-0005(EN)

13 Table 8.2. Background dose rates around Risø (cf. Fig. 8.2 and Fig. 1) measured with thermoluminescence dosimeters (TLD) in the period May October (Results are normalized to nsv h 1 ) Risø zone Location nsv h 1 I 1 35 I 2 46 I 3 79 I 4 - I 5 57 Mean 54 II P1 42 II P2 63 II P3 68 II P4 51 Mean 56 III P1 56 III P2 57 III P3 53 Mean 55 IV P1 39 IV P2 38 IV P3 50 IV P4 51 IV P5 42 IV P6 43 IV P7 50 Mean 45 V P1 49 V P2 55 V P3 54 V P4 40 V P5 60 V P6 50 V P7 45 V P8 61 V P9 61 V P10 61 Mean 54 DTU-Nutech-R-0005(EN) 13

14 Table 8.3. Terrestrial dose rates at the Risø zones (cf. Fig. 8.2 and Fig. 1) July - December Measured with a NaI(Tl) detector. (Unit: nsv h 1 ) Risø zone Location October I P1 41 I P2 50 I P3 366 I P4 45 I P5 75 Mean 116 II P1 45 II P2 45 II P3 43 II P4 43 Mean 44 III P1 49 III P2 50 III P3 48 Mean 49 IV P1 37 IV P2 48 IV P3 48 IV P4 47 IV P5 46 IV P6 42 IV P7 46 Mean 45 V P1 43 V P2 54 V P3 55 V P4 46 V P5 50 V P6 49 V P7 40 V P7a 46 V P8 51 V P9 53 V P10 42 Mean DTU-Nutech-R-0005(EN)

15 Fig. 1. Locations for measurements of gamma-background radiation Zone I and II (cf. Tables 8.2 and 8.3) DTU-Nutech-R-0005(EN) 15

16 137 Cs µbq m Cs µbq m Week Fig Caesium-137 in ground level air collected at Risø in July-December (Unit: µbq m 3 ) Week Be-7 Pb-210 Fig Beryllium-7 and lead-210 in ground level air collected at Risø in July- December (Unit: µbq m 3 ) 16 DTU-Nutech-R-0005(EN)

17 60 DL kbq 3 H m Year Fig Tritium in precipitation collected at Risø ( 1 m 2 rain collector ) (Unit: kbq m 3 ; DL = detection limit ) 120 DL kbq 3 H m Year Fig Tritium in precipitation collected at Risø ( 10 m 2 rain collector ) (Unit: kbq m 3 ; DL = detection limit ) DTU-Nutech-R-0005(EN) 17

18 Bq 137 Cs kg -1 dry weight Year Fig Caesium 137 in sediment samples collected at Bolund in Roskilde Fjord (Unit: Bq kg 1 dry matter) 18 DTU-Nutech-R-0005(EN)

19 Salinity in o/oo Cs-137 Salinity 20 Bq 137 Cs m Year 0 Fig Caesium 137 in seawater collected in Roskilde Fjord (Unit: Bq m 3 ) 120 DL kbq 3 H m Year Fig Tritium in seawater collected in Roskilde Fjord (Unit: kbq m 3 ; DL = detection limit ) DTU-Nutech-R-0005(EN) 19

20 700 eqv. mg KCl Year Fig Total-beta radioactivity in waste water collected at Risø (Unit: eqv. mg KCl l 1 ) 20 DTU-Nutech-R-0005(EN)

21 Fig Locations (1-6) for TLD measurements around the border of Risø (cf. Table 8.1). DTU-Nutech-R-0005(EN) 21

22 Fig Locations for measurements of background radiation around Risø in Zones III, IV and V. 22 DTU-Nutech-R-0005(EN)

23 DTU-Nutech-R-0005(EN) 23

24 Center for Nuclear Technologies is Denmark s national competency center for nuclear technology. With roots in research in the peaceful use of nuclear power, DTU Nutech works with the applications of ionizing radiation and radioactive substances for the benefit of society. DTU Center for Nuclear Technologies Technical University of Denmark Frederiksborgvej 399 PO Box 49 DK-4000 Roskilde Denmark Phone Fax