Consequences of severe radioactive releases to Nordic Marine environment:Final report for the NKS-B activity 2012

• Main Authors: Iosjpe, M., Isaksson, M., Joensen, H.P., Lahtinen, J., Logemann, K., Pálsson, S.E., Roos, Per, Suolanen, V.
• Format: Book
• Language: English
• Published: NKS Secretariat 2013
• Subjects: NKS-276; Severe radioactive releases; Marine environment; Nuclear power plants; Submarines; Doses; /dk/atira/pure/sustainabledevelopmentgoals/life_below_water; SDG 14 - Life Below Water; Norway; Fukushima; Faroes; Iceland; North Atlantic
• Online Access: https://orbit.dtu.dk/en/publications/88ca8b21-696d-455a-b63a-5dfda9938274; https://backend.orbit.dtu.dk/ws/files/52717022/NKS_276.pdf

In the report, consequences of hypothetical severe nuclear accidents releases to Nordic marine environment are preliminary considered. The considered marine area comprises the Baltic Sea (Sweden, Denmark, Finland) and the North Atlantic (Iceland, Faroes, Norway) areas. The hypothetical severe nuclear accidents can be related to nuclear power plants, nuclear powered submarines or ice-breakers. Quite comprehensive survey on radioactive source terms of extremely severe nuclear power and submarine accidents has been done. This enables to estimate more realistically possible radioactive releases of various elements and nuclides to marine environment. One recent reference is of course the Fukushima accident and estimated releases there. The marine flows and dilution circumstances around the Nordic nuclear power plants and in the Baltic Sea area in general, has been studied. Respectively marine flows related to Iceland and Faroes coasts are considered with measured data and with preliminary 3D-model simulations. The substantial depth of sea water in the North Atlantic affect vertical concentration profiles to some extent. At Icelandic or Faroese waters, a potential submarine accident would likely occur in a well defined water mass, and radioactivity from the accident would be detected and spread with the flow regime of the water mass in the world ocean. Based on hypothetical severe accidents scenarios, preliminary consequence calculations has been done. It should be emphasised that the considered severe accident cases, considered in this study, do not directly attach any specific Nordic nuclear power plant or any specific submarine type. The considered radioactive releases will, however, provide specified references for more extensive consideration of environmental consequences of severe - or minor – radioactive releases to Nordic marine environment. As a reference, the release amounts from a 3000 MWth reactor size were used. Based on source term analyses, the chosen release fractions in the study were: iodine 20% (of ...