R SE9800283 l-ebruary 1998 ISSN 1104-9154 DEFENCE RESEARCH Scientific report ESTABLISHMENT Site-sensitive Hazards of Potential Airborne Radioactive Release from Sources on the Kola Peninsula R. Bergman*, L. Thaning*, and A. Baklanov*1 *The Defence Research Establishment (FOA), Umea, Sweden ** Kola Science Centre of Russian Science Academy, Apatity, Russia KNNP Ground contamination after 5 days Total release: 1 Bq Start971228 00GMT Duration: 1 h Height: 100 m Dry + wet deposition Bq/m > 10 •" > io13 > io12 > 10" 1OOO 1900 2000 25O0 Start Um« 981228 OOOO - Slop time 9S122B 01 00 HEIGHT 100 m Submarine Ground contamination after 5 days Total release: 1 Bq Start 961228 00 GMT Duration: 1 h Height: 100 m Dry + wet deposition Bq/m > 10H > 10 " -12 I •11 > 10 1000 1500 2000 2MO Start Urn* J91228 0000 - Stop tfrrw 581228 0100 HDCHT 100 m Division of NBC Defence 29-4 SE-901 82 UMEA DEFENCE RESEARCH ESTABLISHMENT FOA-R-98-00717-861-SE Division of NBC Defence February 1998 SE-901 82 UMEA ISSN 1104-9154 SWEDEN Ronny Bergman, LennartThaning, Alexander Baklanov Site-sensitive Hazards of Potential Airborne Radioactive Release from Sources on the Kola Peninsula Distribution: FOA: Issuing organization Document ref. No., ISRN Defence Research Establishment FOA-R-98-00717-861 -SE Division of NBC Defence Date of issue Project No. SE-901 82UMEA February 1998 E479 SWEDEN Project name (abbrev. if necessary) Long-term consequences of radioactive fallout Author(s) Initiator or sponsoring organization FOA, OCB Ronny Bergman, Lennart Thaning, Alexander Project manager Baklanov Lars Rejnus Scientifically and technically responsible Ronny Bergman Document title Site-sensitive Hazards of Potential Airborne Radioactive Release from Sources on the Kola Peninsula Abstract An abstract of this paper has previously appeared in Extended abstracts volume 2 from the Third International Conference on ENVIRONMENTAL RADIOACTIVITY IN THE ARCTIC, Troms0, Norway June 1-5, 1997. In this work we focus on cases of airborne releases from some of the sources on the Kola Peninsula - primarily nuclear reactors on submarines and the Kola Nuclear Power Plant (KNPP). The purpose of our study is to illustrate, and discuss some features - dependent on site and release characteristics - of the deposition patterns resulting from assumed unit radioactive releases to the atmosphere from a location at a fjord and from the KNPP in Polyarnye Zori. Using meteorological data for one real weather situation, the analysis is based on simulating the transport in air of assumed radioactive releases and estimating the deposition pattern on local, meso- and regional scales. By allowing unit releases to occur simultaneously from the site at the fjord and from the power plant (and with the same release profile in time) comparisons are made of differences in deposition patterns in and outside the Kola region. In this case study a set of as- sumed release heights, durations of the release, and particle size distributions are applied to indicate the dependence for the resulting deposition pattern on these parameters. Keywords Radioactive, risk, source, Kola, release, airborne, Further bibliographic information Language English ISSN 1104-9154 ISBN Pages p. 14 Price Ace. to pricelist Distributor (if not issuing organization) Dokumentets utgivare Dokumentbeteckning, ISRN Försvarets forskningsanstalt FO A-R--98-00717-861 --SE Avdelningen för NBC-skydd Dokumentets datum Uppdragsnummer 901 82 UMEÅ Februari 1998 Projektnamn (ev förkortat) Långsiktiga radiakproblem Upphovsman(män) Uppdragsgivare FOA, ÖCB Ronny Bergman, Lennart Thaning, Alexander Projektansvarig Baklanov Lars Rejnus Fackansvarig Ronny Bergman Dokumentets titel i översättning Lägesberoende risker för Iuftburna radioaktiva utsläpp från källor på Kolahalvön Sammanfattning Rapporten behandlar fall av utsläpp i luften från några källor av särskilt intresse på Kolahalvön - främst kärnreaktorer på ubåtar och kärnkraftverket vid Imandrasjön. Syftet är att illustrera och analysera huvuddragen - beroende på geografiskt läge och utsläppskaraktäristik - avseende de beläggningsmönster som uppkommer efter antagna atmosfäriska utsläpp av enhetsaktivitet från en plats vid en fjord och från kärnkraftverket Polyarnye Zori. Beräkning och analys av depositionsmönstret på lokal nivå samt på meso- och regional skala görs med användning av meteorologiska data för en verklig vädersituation och simulering av transporten i luft av det antagna radioaktiva utsläppet. Genom att låta enhetsutsläppen ske samtidigt från läget vid fjorden och vid kärnkraftverket (och med samma utsläppsprofil i tiden) görs jämförelser av skillnader i depositionsmönster i och utanför regionen på Kola. Denna fallstudie utgår från ett antal antagna utsläppshöjder, tidsintervall för utsläppen och partikelfördelningar för att indikera beroendet för det resulterande beläggningsmönstret på dessa parametrar. Nyckelord Radioaktiv, risk, källa, Kola, utsläpp, luftburen Övriga bibliografiska uppgifter Språk Engelska ISSN 1104-9154 ISBN Omfång 14 Pris Enligt prislista Distributör (om annan än ovan) INTRODUCTION Several studies dealing with radioactive sources and actual or potential contamination in the whole or part of the Arctic (AMAP 1994, NACC 1995, OTA 1995, Bellona 1996, IIASA 1996) consistently indicate that most Arctic sources of substantial radiological concern are to be found in north-western Russia on the Kola Peninsula, Novaya Zemlya and in the adjacent Barents and Kara Seas. In this paper we focus on cases of airborne releases from some of these sources - primarily nuclear reactors on submarines and the Kola Nuclear Power Plant (KNPP). The purpose with our study is to illustrate, and discuss some features - dependent on site and release characteris- tics - of the deposition patterns resulting from assumed unit radioactive releases to the atmos- phere from a location at a fjord and from the KNPP in Polyarnye Zori. We don not attempt to describe the probability for - and the chain of events leading to signifi- cant radioactive releases. However, based on previous assessments of the probable upper level of the inventory - primarily of 137Cs in reactor fuel used in submarines (NACC 1995, Gussgard 1995) - we scale the deposition derived from our calculation of unit release to reflect release of 100 % of the inventory. (The radioactive deposition at various distances associated with other assumptions about the fraction released to the environment may thus easily be obtained by another choice of the scaling factor.) We discuss the hazards indicated for areas in the vicinity and far from these sources, as well as illustrate uncertainties involved in generalisations from case studies like this. SIMULATIONS OF RELEASES TO THE ATMOSPHERE Using meteorological data for one real weather situation, the analysis is based on simulating the transport in air of assumed radioactive releases and estimating the deposition pattern on local, meso- and regional scales. By allowing unit releases to occur simultaneously from the site at the fjord and at the power plant (and with the same release profile in time) compaiisons are made of differences in deposition patterns in and outside the Kola *--- region. In this case study a set of assumed release heights, ;:-Case studies ol release from durations of the release, and particle size distributions are -a flora site anfl uie ivom "> applied to indicate the dependence for the resulting deposition pattern on these parameters. These sets of lsfi?^0^ ^rKnfrs parameters values are illustrated to the right. j •Initial plume rise The deposition patterns based on unit release from a fjord 100, 300, 500, 1000 m site and the location of the Kola Nuclear Power-Plant ex- _ ,. _,...... hibit the range of significant deposition subsequent to a 0.3u•Particlm aned siz3uem distribution release under the specific weather conditions prevailing at a (median radius, lognormal) certain date close and far from the source - and at a deposition coefficient of 1.5 mm/s, which is assumed ap- •Deposition velocity propriate for the particulate carrier concerning deposition at 1.5 mm/s and 15 mm/s relatively long distances in the Chernobyl case (Devell I 'Deposition with and 1991), and similar to the standard value of 1 mm/s. L ^Aout jgredpitation Regional transport For the simulation on the regional scale, the MATHEW/ADPIC model has been used. MATHEW/ADPIC was developed at the Lawrence Livermore National Laboratory (LLNL), USA (Sherman, 1978, Lange, 1978, Foster, 1992) and has been adjusted at the Defence Re- search Establishment (FOA) for the FOA-environment (Thaning & Naslund, 1991, Naslund & Holmstrom, 1993). In ADPIC, the dispersion is described by a Particle-in-Cell model. The 3D model wind field, in which the particles are advected, is mass consistent and produced by in- terpolating real wind data from the European Centre for Medium-Range Weather Forecasts (ECMWF), Reading, UK into the model grid. The FOA version of the model has been com- pared with the ETEX-1 Full-scale Experiment, and has been proved to be capable of producing a realistic evolution in time for the concentration (Thaning and Johanson 1995, Noclop 1997). The calculations for regional scale have been carried out for the region of Scandinavia, Finland and Northwest Russia including the Kola Peninsula at a distance up to 2000 km. The release parameter variations for the model calculations include the particle size distribution, height of release, duration of release, wet or dry deposition and release site. Figure 1 illustrate