The radiological environment of Svalbard

Abstract

This paper presents a detailed survey of the radiological environment of the Svalbard area carried out from 2000 to 2002, in both the marine and terrestrial environment. In the marine environment in 2001, 99 Tc activity concentrations in seawater were 0.13 to 0.36 Bq/m 3 , 5 fold higher than those in 1994, refl ecting the increase in 99 Tc discharges from Sellafi eld in the mid 1990s. Cs-137 activity concentrations in seawater were 2.23 to 2.43 Bq/m 3 , ca. 10 fold lower than those in the 1980s, refl ecting the reduction in discharge of this radionuclide. Pu-238, 239+240 Pu and 241 Am activity concentrations in seawater were < 0.3 to 0.7 mBq/m 3 , 5.6 to 8.9 mBq/m 3 and 0.6 to 2.4 mBq/m 3 respectively, with activity ratios suggesting global fallout to be the dominant source. Tc-99 activity concentrations in brown algae were up to 18 fold higher than those in the 1980s with highest concentrations in Fucus distichus (25.7 to 58.7 Bq/kg d.w.). In the terrestrial environment, typical 137 Cs activity concentrations in soil were between < 0.5 and 63 Bq/kg d.w. whilst activity concentrations of the natural radionuclides 238 U (17 to 72 Bq/kg d.w.), 226 Ra (21 to 70 Bq/kg d.w.), 232 Th (10 to 57 Bq/kg d.w.) and 40 K (115 to 818 Bq/kg d.w.) were similar to global averages. In terrestrial vegetation, 137 Cs activity concentrations varied from 29 to 292 Bq/kg d.w. in mosses, 30 to 140 Bq/kg d.w. in lichen and 19 to 109 Bq/kg d.w. in fl owering plants. Elevated activity concentrations of 137 Cs, 238 U, 226 Ra, Pu isotopes and 241 Am were found in some matrices associated with seabird colonies.

Sources and pathways of artificial radionuclides to soils at a High Arctic site

“…Due to the scarcity of observations, the sources of radionuclides and their deposition fluxes to soils are not well constrained for the Arctic. For Svalbard, data on anthropogenic radionuclide contents in the terrestrial environment can be found only in the synthetic reports (AMAP 1997 , 2004 ) or in few case studies conducted on tundra soils and peats in the Ny-Ålesund and Hornsund areas (Reszka and Szczypa 1991 ; Dowdall et al 2003 , 2005a , b , c ; Gwynn et al 2004a , b ; Łokas et al 2013 a). Even, less is known about the distribution of radionuclides in the areas deglaciated since the Little Ice Age, which are an important element of the present day landscape of Svalbard (Rachlewicz et al 2007 ).…”

“…An approach applied in this study combines determinations of activity concentrations and ratios of the fallout radionuclides ( 238 Pu, 239 + 240 Pu, 241 Am and 137 Cs) in soil profiles with the analyses of soil properties in order to quantify deposition, identify sources, and assess the possibility of post-depositional mobility of these radionuclides. While determinations of radionuclide inventories in soils provide information on their cumulative deposition, only measurements of the vertical patterns of radionuclide activity in soil profiles allow to address temporal variations in deposition fluxes and the post-depositional mobility of radionuclides (Gwynn et al 2004a , b ; Łokas et al 2013 a). Additionally, the analyses of activity ratios allow identification of the ultimate sources of the radionuclide contamination which can be the global fallout from nuclear weapons testing or the regional sources (Salbu 2001 ; Łokas et al 2013 a; Van Pelt and Ketterer 2013 ).…”

Radionuclide activities in sediments on the northern coast of Spitsbergen

“…Perhaps the distribution of 137 Cs was also a result of atmospheric transport and deposition (AMAP 2004;Romanov 2004;Vana 2004;Sapota et al 2009 (Gwynn et al 2004) while the radioactivity of 137 Cs in the North Atlantic water was below 1.5 Bq/m 3 (Gulin and Stokozov 2005) and in the Barents Sea around 3 Bq/m 3 (Strand et al 2002). This is due to the scattering of air masses contaminated with 137 Cs being transported from Chernobyl to the northwest.…”

“…Different radioactivity levels of anthropogenic 137 Cs in soils, bottom sediments and living organisms have been also noted (Gwynn et al 2004;Andersen et al 2006;Stepanets et al 2007;Zaborska et al 2010). Measurements of radioactive isotopes appearing after nuclear tests in the near-bottom waters were performed intensively in the 1950s and at the beginning of the 1960s.…”

“…Anthropogenic radioactive isotopes as well as their migration are investigated more often because of their potential dangerous influence on humans (UNSCEAR 2000;Strand et al 2002;AMAP 2003AMAP , 2004. Although data concerning natural gamma emitters in Svalbard are still lacking, Gwynn et al (2004) reported 137 Cs concentrations from seawater and sediments from several sites in Kongsfjorden and Isfjorden.…”