On Weapons Plutonium in the Arctic Environment (Thule, Greenland)

Abstract

This thesis concerns a nuclear accident that occurred in the Thule (Pituffik) area, NW Greenland in 1968, called the Thule accident. Results are based on different analytical techniques, i.e. gamma spectrometry, alpha spectrometry, ICP-MS, SEM with EDX and different sediment models, i.e. (CRS, CIC). The scope of the thesis is the study of hot particles. Studies on these have shown several interesting features, e.g. that they carry most of the activity dispersed from the accident, moreover, they have been very useful in the determination of the source term for the Thule accident debris. Paper I, is an overview of the results from the Thule-97 expedition. This paper concerns the marine environment, i.e. water, sediment and benthic animals in the Bylot Sound. The main conclusions are; that plutonium is not transported from the contaminated sediments into the surface water in this shelf sea, the debris has been efficiently buried in the sediment to great depth as a result of biological activity and transfer of plutonium to benthic biota is low. Paper II, concludes that the resuspension of accident debris on land has been limited and indications were, that americium has a faster transport mechanism from the catchment area to lakes than plutonium and radio lead. Paper III, is a method description of inventory calculation techniques in sediment with heterogeneous activity concentration, i.e. hot particles are present in the samples. It is concluded that earlier inventory estimates have been under estimated and that the new inventory is about 3.8 kg (10 TBq) of 239,240Pu. Paper IV, describes hot particle separation/identification techniques using real-time digital image systems. These techniques are much faster than conventionally used autoradiography and give the results in real time. Paper V, is a study of single isolated hot particles. The most interesting result is that the fission material in the weapons involved in the accident mostly consisted of 235U (about 4times more in mass than 239Pu). This paper concludes that there are at least two different source terms for the Thule accident debris. Another interesting feature is that it seems like uranium is leaching from the particles faster than plutonium and americium.

Abstract (Swedish)

Popular Abstract in Swedish

I januari 1968 inträffade en flygplansolycka på havsisen ca 12 km väster om Thule flygbasen på nordvästra Grönland. Flygplanet, en amerikansk B-52, hade fyra kärnvapen ombord, som sprängdes sönder när planet störtade. Sprängningen orsakades av de konventionella sprängmedel som satt runt kärnladdningarna i de fyra vapnen. Dessa sprängningar var ej av nukleär art, d.v.s. ingen fission av laddningarna skedde. Man konstaterade att ca 6 kg plutonium spreds runt olycksplatsen, varav ca 3 kg rensades upp i en dekontamineringsoperation som skedde de tre följande månaderna efter olyckan. I avhandlingen behandlas data från den senaste av de 7 expeditioner som genomförts i detta område. Det konstateras som tidigare, att strålningsdosen till lokalbefolkningen (inuiterna) via födointag är försumbar. Under de 34 år som gått är den integrerade absorberade stråldosen lika med tre veckors exponering av bakgrundstrålning i detta område. I detta arbete beskrivs ett sätt att uppskatta aktivitetskoncentrationer i havssediment när dessa innehåller plutonium i form av s.k. hetpartiklar. Denna metod att uppskatta aktivitetskoncentrationen av plutonium i havssediment visar att tidigare uppskattningar är underskattade. Dessutom har en studie gjorts för att utreda källtermen för bombmaterialet (källterm kan liknas vid ett fingeravtryck, d.v.s. man kan särskilja material från olika källor). Denna studie har visat att det finns fler än en källterm, troligen endast två, för det bombmaterialet som var involverat i olyckan. I åtminstone en av dessa källor är det huvudsakliga fissionabla matrerialet uran (235-U), ca fyra gånger mer än plutonium (239-Pu).

• author: Eriksson, Mats
• supervisor: [unknown] [unknown]
• opponent: Prof. Allard, Bert, Institutionen för Naturvetenskap, Örebro Universitet
• organization: Medical Radiation Physics, Lund
• publishing date: 2002
• type: Thesis
• publication status: published
• subject: Radiology, Nuclear Medicine and Medical Imaging
• keywords: Nuclear physics, Kärnfysik, Nuclear medicine, radiobiology, Nukleärmedicin, radiobiologi, Nuclear engineering and technology, Kärnteknik, realtime digital image systems, SEM, ICP-MS, alpha spectrometry, gamma spectrometry, heterogeneous activity concentration, hot particle, separation technique, isotopic ratio, inventory, source term, fallout, americium, uranium, plutonium, radionuclide, Bylot Sound, Greenland, Thule, environmental radioactivity, nuclear accident
• pages: 148 pages
• defense location: Onkologiska klinikens föreläsningssal, Lunds Universitetssjukhus, Lund
• defense date: 2002-05-03 10:15:00
• ISBN: 87-550-3006-8
• language: English
• LU publication?: yes
• additional info: Article: Paper I, Dahlgaard H, Eriksson M., Ilus E., Ryan T., McMahon C.A. and Nielsen S.P.Plutonium in the marine environment at Thule, NW-Greenland after a nuclear weapons accidentIn: "Plutonium in the environment", Elsevier, 15-30, 2001. Article: Paper II, Eriksson M., Holm E., Roos P. and Dahlgaard H.Flux of (238,239,240)Pu, (241)Am, (137)Cs and (210)Pb to High Arctic Lakes in the Thule District (Greenland)Journal of Environmental Radioactivity, submitted (19 pp) 2001. Article: Paper III, Eriksson M.Plutonium Inventory Calculations in Sediments when Hot Particles are PresentManuscript, (25 pp), 2002. Article: Paper IV, Eriksson M., Ljunggren K. and Hindorf C.Plutonium hot particle separation techniques using real-time digital image systemsNuclear Instruments and Methods in Physics Research, A, in press (6 pp), 2002. Article: Paper V, Eriksson M., Roos P., Dahlgaard H., Lindahl P. and Holm E.Isotopic ratios in Thule hot particles, source term of the Thule debrisManuscript, (18 pp), 2002.
• id: a04274cf-697f-4095-8e51-b1d1bceb3285 (old id 464579)
• date added to LUP: 2016-04-01 15:17:51
• date last changed: 2021-04-23 09:10:23