Radioecology in the Arctic: Activities of the New Environmental Protection Unit of the NRPA in Tromsø
Total Page:16
File Type:pdf, Size:1020Kb
Radioecology in the Arctic: Activities of the new environmental protection unit of the NRPA in Tromsø Sebastian Gerland and Bjørn Lind N orwegian Radiation Protection Authoritv, Environmental Protection Unit, Polar Environinental C entre, 9296 TromnsØ. Norway lntroduction Radioactivity in the Aretic is a central topic within environmental pollution issues (AMAP 1998. Strand 2001). Sources, both actual and potential, for radioactive pollution in the Arctic are marine and atmospheric long-range transported radionuclides, originating from nuclear power and reprocessing plants. dumped radioactive waste, accidents with nuclear powered/ armed ships and submarines and nuelear test explosions (for an overview on sources see e.g. Aarkrog, 1993). In August 1999, the Norweglan Radiation Proteetion Authority (Statens strålevern) established an Environmental Protection Unit in the Polar Environmental Centre (Fig. 1) in Trormsø, northern Norway. Major tasks of the three persons at the unit include monitoring and research in both marine and terrestrial environments in northern Eurasian areas and the Arctic. This includes field and laboratory work, collaboration with the other institutions within the Polar Environmental Centre (e.g. the Norwegian Polar Institute}, and integrating studies within the AMAP programme (AMAP, 1998). The Environmental Protection Unit was recently involved in fieldwork in Kongsfjorden (Svalbard), an international cruise to the Fram Strait, a technetium monitoring program in the Western Barents Sea, and radiation measurements on the site in the Barents Sea where the Russian submarine 'Kursk" sunk (see Amundsen & Lind, 2001). Figure 1. Polar Environmental Centre and Polaria in Tromsø, Northern Norway (from http://www.polarenvironnment.no/). *| | | _ ~~~~~~~~~~~... :,......-0.s Kongsfjorden, Svalbard Western Svalbard is characterised by its high Aretic environment with a relatively mild climate, arising from the nearby passage of the West Spitsbergen Current, a branch of the North Atlantic Current. The determination of radionuelide levels, their temporal and spatial variations and investigations concerning Aretic-specific processes provides insiØht into radionuelide behaviour and long-range transport of contaminants to Svalbard. At Ny-Alesund/Kongsfjorden (Fig. 2), 97 fieldwork was performed in May 2000. In the fjord, surface .seawater ( 13'Cs, Pu/Am isotopes, 95Te, Fig. 3), sea ice (137Cs total -{ganalysis), different types of seaweed (99Te), and seafloor sediments (total. y-analysis, Pui/Amn isotopes) were samnpled. whereas on land, plants and soil samples (total y- analvsis) wkvere taken. Radionuelide rneasurements are cturrently on the way. Figure 2. Map of Svalbard with Ny-Alesund (Kongsfjorden), and the islands of Hopen and BjØrnØya. In the inset the location of the sampling station Hillesøy at the Norwegin coast is marked. Investigation of "9Te concerutration factors on seaweed showed large variations. depending on seaweed. types. In the mnid-90s, a dramatic increase in 9>9'rc discharges from Sellafield began, the effect of which was subsequently registered at distant locations in the Norwegian Sea where elevated environmental concentrations of 99Tc could be measured (Brown. et al,, 1999; Kolstad & Rud'jord. 2000). It is of interest to speculate as to the spatial extent of contamination arising from the releases and how the levels. have changed over tine. Preliminary results of our samnples. from May 2000 indicate similar levels of 99Tc in seawater to those measured in the western Barents Sea in 1999 (Kolstad & Rudjord, 2000). Measurements on seawater west of Svalbard in 1995, undertaken before the inerease of 99 releases from the Tcnid 90s could have reached the Aretic, show values about four times lower (Kershaw et al., 1999). However, before concluding from this evidence that a connection with the newer releases at Sellafield exists, we want to study levelshT and changes with time in the Svalbard area more thoroughlyl Figure 3. Surface water sampling from a rubber boat forw 37Cs measurevrents in Komgsfjorden in May 2000. At the same ohacionasea ice was sampled and melted for and changes wih t nCorreponding analyses (Photo: S. Gerland). 98 Fram Stralt 4Most of the sea ice which forms on the shelf and estuary areas off Siberia and Alaska leaves the Aretic Ocean through the Fram Strait, the area between the Arctic Ocean and Northern Atlantic in the north and south, and Greenland and Svalbard in the west and east. With participation of two researchers of the NRPA, water. iee, sediments and biota were sampled for radionuelide mneasurements along a transecet at 790 N on beard of the RV "Polarstern" in August 2000 (Gerland & Grottheinm, in press). By folHowing this transect, water prot:les in the East Greenland Current, coming from the north, and West Spitsbergen Current, conming from the south, were obtained. In addition, sediments from "dirty" multi-year sea ice were recovered (Fig. 4). Results from measurements on these Iong-distance transported sediments are going to be used also within numnerical modelling work- on ice transport by losjpe (2001). ~~ ~ ~~ ~~Figure 4. Sampling of "dirty ice" with l_l..........a.... helicopter on a multi-year sea ice floe in the Framn Strait during the RV "Polarstern" cruise in August 2000 (Photo: S. Gerland). Technetium-99 monitoring Technetium-99 is an artificial radionuclide that was and still is released into the sea at European nuelear reprocessing plants (e.g. Sellafield, Uj.K.). A monitoring program for establishing time series of ' Te concentrations in the Barents ',ea and Svalbard areas was started in October 2000 with continuing monthlv sampling of sea water at the islands of Bjømøya and Hopen (Fig. 2). [n addition to monthly measurements from Hillesøy at the Norwegian coast (Kolstad & Rudjord, 2000) and occasional sampling at other coastal sites in Norway, these two sampling locations should give information on the spreading øf radionuelides from European nuclear reprocessing plants to the Aretic. The measurements on the first samples from this initiative are currently on the way. For March 2001. we plan to extend the network further ineluding also Ny-Alesund at Kongsfjorden and the island of Jan Mayen cast of Greenland to the set of stations with monthly sampling. Sunken submarine "Kursk" On 12 August 2000, the Russian nuelear powered submarine Kursk sunk north of the Kola Peninsula in the Barents Sea. The Environmental Proteetion Unit participated actively in monitoring of the environment and performed radiation protection for the divers during work inside and close to the submarine's hull. On-site measurernents on environmental samples and debris were performed using Nal and Hp-Ge detectors as well as dose rate meters. Collected samples (seawater and sediments) were brought to the NRPA laboratory at østerås for more accurate analyses. No 99 increased levels above normal were registered. Details on this activity and results are given by Amundsen & Lind (2001). Outlook Aims for 2001 include installation of laboratory facilities with HP-Ge detector and technetium 3- radiation detector equipment, extension of collaboration within the Polar Environmental Centre (active participation in its "centre programs") and external institutions, as well as follow up of field activities in northem areas. Time series from the mentioned monitoring sites should give indications on sources of radionuclides. Another aim will be to give contributions regarding the question of how arctic climate is affecting transport and effects in radioecology compared to known processes in milder conditions. Acknowledgements I. Amundsen and S. GrØttheim (both NRPA) participated in fieldwork presented here. We are further grateful to A.K. Kolstad and A.-L. Brungot (both NRPA), who did substantial laboratory work on samples in the context of this contribution. S. Borghuis (NRPA) provided the map (Fig. 2). J. Brown (NRPA) helped with discussions and by reading a draft of this contribution. Personnel of the Norwegian Meteorological Institute (DNMI) in TromsØ and on Bjørnøya and Hopen are helping with monthly sampling at these islands. The macroalgae group of C. Wiencke (Alfred Wegener Institute (AWI) for Polar and Marine Research, Bremerhaven, Germany) sampled seaweed while diving. H. Nies (Federal Maritime and Hydrographic Agency of Germany, Hamburg), U. Schauer (AWI) and J-G. Winther (Norwegian Polar Institute, Tromsø), loaned equipment to us and supported us in the field. References Aarkrog, A. 1993: Radioactivity in polar regions - main sources. In: Strand, P. and Holm, E. (Eds.): Environmental Radioactivity in the Arctic and Antarctic. østerås, Norway, 15-34. AMAP 1998: Chapter 8: Radioactivity (eds: P. Strand et al.). AMAP Assessment Report: Arctic Pollution Issues. Arctic Monitoring and Assessment Programme (AMAP), Oslo, Norway, 525-619. Amundsen, I. & Lind, B. 2001: Monitoring of radioactivity at the Russian nuclear submarine "Kursk". This volume. Brown, J.E., Kolstad, A.K., Brungot, A.L., Lind, B., Rudjord, A.L., Strand, P. & FØyn, L. 1999: Levels of 99Tc in seawater and biota samples from Norwegian coastal waters and adjacent seas. Marine Pollution Bulletin 38 (7), 560-57 1. Gerland, S. & Grøttheim, S. in press: Transport of artificial radionuclides with ocean currents, sea ice and particulate matter; in: G. Krause & U. Schauer (Eds.): Scientific Cruise Report of the Arctic Expedition ARKXVl/l+2 of RV "Polarstern" in 2000, Reports on Polar Research, AWI, Bremerhaven, Germany. 100 Kershaw, P.J., McCubbin, D. & Leonard, K.S. 1999: Continuing contamination of north Atlantic and Arctic waters by Sellafield radionuclides. Science of the Total Environment 238, 119-132. Iosjpe, M. 2001: Box modelling approach for evaluation of influence of ice transport of radionuclides for doses to man. This volume. Kolstad, A.K. & Rudjord, A.L. 2000: Radioactive pollution in the marine environment - 99Tc in seawater and biota in 1998 and 1999. Strålevern Rapport (in Norwegian) 7, NRPA, østeras, Norway, 17 pages. Strand, P. 2001: Radioactivity in the Arctic. This volume. 101.