The surtax in Sweden, which exclusively applies for nuclear power plants, in conjunction with low electricity prices, has forced Swedish nuclear power plants to minimize their expenses. At Oskarshamn power plant, estimation of cost, associated with low-level nuclear waste management has been conducted several years ago, but with lacking knowledge about how the calculations were performed. Therefore, the purpose of this project was to establish an independent cost estimation for compactible and non-compactible, low level and medium level nuclear waste. Cost estimates for free released low-level nuclear waste was also performed. By analyzing average economic figures from year 2014-2015 and visits on-site, an excel-based calculation template was accomplished. During the on-site studies, several visits to the low-level nuclear waste management facilities at Oskarshamn power plant were made, in order to get an overview of how the handling process works. By following the staff around, it was possible to estimate some of the time durations for the different parts in the handling process for compactible lowlevel nuclear waste, that were used in the calculations. The price for compactible low-level nuclear waste was calculated to 6,72 - 6,97 kr/kg, depending on the activity level. The non-compactible low-level nuclear waste price was found to vary between 4 – 48 kr/kg. The large fluctuations are due to different activity levels and associated additional costs in handling, measuring, final deposition etc. For both compactible and non-compactible nuclear waste, the storage cost is a factor that dominates the total cost and that could be minimized. Based on the analysis presented in this work, the cost can be decreased by reducing the storage time and/or store the nuclear waste in a more space efficient way. The cost estimate for free released material is low (5,94 – 8,74 kr/kg), which concludes that Oskarshamn power plant may profit from free releasing as much material as possible, due to the fact that it is highly profitable to recycle metals.

This project is a part of the radiological characterization of the Gamma hall and the Radiochemistry laboratory (RKL) at The Svedberg laboratory. Measurements of surface contamination in both premises have been done by taking wipe-test samples from the floors and walls in the two rooms. A 3D model of both premises has been designed in MATLAB. The model shows the distribution of the measurement points and their contamination values on the floors and walls in these premises. Measurements of the surface contamination were done with two different methods. The results of the measurements do not indicate any contamination in the Gamma hall. In the Radiochemistry laboratory small amount of the contamination has been detected mostly on the floor.

I början av 1900-talet ansågs radium vara ett försäljningsargument för olika hushållsartiklar. Föreliggande studies syfte var att undersöka hur förhållandet till radium i hushållsnära varor såg ut i Sverige under tidsperioden 1900–1930. Syftet var även att undersöka vilka argument, om helbrägdagörande och vetenskapliga, som gavs för att sälja dessa produkter. Ur detta syfte skapades följande frågeställningar. 1. Hur skildrades radiumets olika aspekter i artiklar och annonser? 2. Vilka psykologiska- och medicinska tillstånd beskrevs dessa produkter vara bra för? 3. Vilka anspråk på medicinsk och vetenskaplig kunskap legitimerade användandet av dessa produkter? 4. På vilket sätt framkom det i annonser och artiklar hälsorisker med användandet? Som källmaterial användes artiklar och annonser ur två dagstidningar. Utöver dessa användes ett antal artiklar skrivna av kemisten John Landin. Materialet tolkades ur media- och medicinhistorisk synvinkel. Med tematisk analys skapades fem huvudkategorier: medicinska, skönhets-, psykologiska, vetenskapliga och strukturella argument för att använda radioaktiva hushållsprodukter. Resultatet pekade på att produkterna legitimeras genom bland annat medicinsk och vetenskaplig expertis. Radiumets nyttoaspekter framhölls, då radiumet sades bota allehanda sjukdomar. Inga risker framhölls med användandet. Därefter diskuteras studiens resultat kopplat till ställda frågeställningar och tidigare forskning samt samtidsrelevans. Slutligen diskuteras undersökningens styrkor och svagheter. / At the beginning of the 20th century, radium was considered a selling point for various household items. The purpose of the present study was to investigate how the relationship to radium in household goods looked like in Sweden during the period 1900-1930. The purpose was also to investigate what arguments, about healing and scientific, were given to sell these products. For this purpose, the following questions were created. 1. How is radium described in articles and advertisements? 2. What psychological and medical conditions are these products described to be good for? 3. What claims to medical and scientific knowledge legitimized the use of these products? 4. In what way do advertisements and articles presented any health risks with their use? As source material, articles-, and advertisements from two daily newspapers were used. In addition, several articles written by the chemist John Landin were used. The material was interpreted from media and medical historical point of view. With thematic analysis, five main categories were created: medical, beauty, psychological, scientific, and structural arguments for using radioactive products. The results indicated that the products were legitimized through, among other things, medical and scientific expertise. The usefulness of radium was emphasized when radium was said to cure all kinds of diseases. No risks were emphasized with the use. Then the results of the study are discussed in connection with questions asked and previous research as well as contemporary relevance. Finally, the strengths and weaknesses of the survey are discussed.

Kärnkraftsolyckan i Tjernobyl ledde till en spridning av radioaktiva ämnen över Europa och Sverige. År 2018 är det 32 år sedan kärnkraftsolyckan ägde rum och den enda radioaktiva isotopen som finns kvar i det svenska ekosystemet som följd av olyckan i en betydande mängd är Cs-137, på grund av dess 30-åriga halveringstid. Genom att bestämma aktiviteten hos svamp kan halten Cs-137 i mark uppskattas. Hösten 2018 kommer det tvärvetenskapliga massexperimentet Strålande jord att utföras i syfte att kartlägga denna halt i hela Sverige. Syftet med detta examensarbete var att nå resultat som är användbara vid aktivitetsbestämning av svamp. Ett numeriskt verktyg för analys av data ifrån gammaspektroskopi har konstruerats. Två metoder för att beräkna händelser (counts) i energitoppar i gammaemissionsspektra har formulerats och varit byggstenar för det vidare arbetet. Under arbetets gång har följande bestämts: effektiviteten hos en high purity germanium (HPGe) detektor, aktiviteten hos två svampprover, attenueringskoeffcienten av 662 keV-gamma för samma svampprover samt för vatten. För att kunna approximera en burk med svamp som en isotropt strålande punktkälla och få goda resultat behöver aktivitetsmätningarna göras med ett långt avstånd mellan provet och detektorn. Att mätningar måste göras på ett långt avstånd gör att approximationen bara är lämplig för ett svampprov med hög aktivitet, vilket blev tydligt i detta examensarbete då aktiviteten hos ett lågaktivt svampprov inte kunde bestämmas med god statistik trots att enskilda mätningar gjordes under närmare en veckas tid. Systematiska fel har inte tagits hänsyn till i detta arbete, utan enbart statistisk osäkerhet. / The nuclear disaster in Chernobyl brought radioactive substances over Europe and Sweden. In 2018 it has passed 32 years since the disaster and the only radioactive isotope that reamins in the swedish ecosystem at a signicant level is Cs-137. By determining activity of mushroom, the amount of Cs-137 in the ground can be estimated. In the fall of 2018, the interdisciplinary mass-experiment Strålande jord will take place with the purpose to map this amount all over Sweden. The purpose of this work was to reach results that could be of use when determining the activity of mushroom. A numerical tool for analysing data from gamma spectroscopy has been constructed. Two different methods for calculating counts in energy peaks from gamma emission spectra have been made and have been the basis for the further work. During this work the following has been determined: The efficiency of a high purity germanium (HPGe) detector, the activity of two different mushroom samples, the attenuation coefficient of gamma at 662 keV for these samples and for water. In order to be able to approximate a can filled with mushroom as an isotropic radiating point source and get accurate results, the activity measurements need to be carried out with a great distance between the sample and the detector. A consequence of this is that this approximation is only suitable for high-activity mushroom, which became evident when the activity of a low-activity mushroom could not be decided with decent statistics even though single measurements were carried out in almost a weeks time. Systematic errors are not considered during this work, only statistical uncertainties.

Tracercenter på Norrlands Universitetssjukhus producerar radiotracers. För att mäta aktiviteten hos de radioaktiva isotoperna används idag en jonkammare tillsammans med mjukvara byggt på Windows XP. Målet med det här examensarbetet är att bygga ny mjukvara som är kompatibelt med Windows 10. Mjukvaran ska tillhandahålla kalibreringsmöjligheter för isotoperna F-18, C-11 och Cs-137 samt kunna överföra uppmätt värde till datahanteringssystemet PETra.Med användandet av kodspråket Python och biblioteket TkInter har ett användargränsnitt och bakomliggande funktionskod utvecklats. Mjukvaran kommunicerar med både jonkammare och PETra seriellt via COM-Port. Linjäritetstester har gjorts för jonkammaren som påvisat god linjäritet. Detta resultat bekräftar mjukvarans tillförlitlighet med en liten felmarginal. Ytterligare tester behövs för att fastställa magnituden av felmarginalen. / Tracercenter at Norrlands University Hospital is a producer of radiotracers. To measure the activity of the radioactive isotopes an Ion Chamber combined with software built on Windows XP is used. The purpose of this thesis is to develop new software for the ion chamber compatible with Windows 10. The software has to provide a calibration function for the isotopes F-18, C-11 and Cs-137 aswell as be able to transfer measured activity to the laboratory information management system PETra.A graphical user interface together with backend code has been developed with Python and the library TkInter. The software communicates with both the ion chamber and PETra with a serial connection via COM-Port. Linearity tests have been made for the ion chamber which has shown that the output of the ion chamber itself is linear. This result confirms the software’s reliability with a slight margin of error. Further tests is needed to determine the magnitude of the margin of error.

Emissions of radionuclides to the atmosphere can lead to wet deposition on plants in theevent of rainfall. An increased level of radioactivity in the plants may occur due tointerception and retention of the radionuclides. If the content of the plants is above thethreshold limit value, entire yields may have to be destroyed. In order to preventcontamination or decrease the content countermeasures can be taken. The impact of thebiomass, leaf area index (LAI) and growth stage of the plant on the interception andretention is important to know in order to decide which countermeasures to use.Weather may also be an important factor. In this work the interception and retention of 134Cs and 85Sr by spring wheat, ley andspring oil-seed rape was studied. The impact of the biomass, LAI and growth stage ofthe plant and precipitation after deposition was also studied. The work was conducted asa field study with plots of the size 1 x 1 m. The plants were wet deposited with 134Cs and 85Sr by using a rain simulator. A total activity of 40 kBq/m2 for both radionuclideswas deposited on each plot. Depositions were performed during four different growthstages and the plants were sampled approximately four hours, one and five days afterdeposition. Activities of the dried plant samples were measured with a High PurityGermanium (HPGe) detector. Finally the interception fraction and the retention factorwere calculated. The study showed that the interception fraction was highest for the third growth stagefor both wheat and oil-seed rape; dough ripeness for wheat and ripening for oil-seedrape. Ley, which was harvested after two depositions, had the highest interceptionfraction at the second growth stage, flowering. Oil-seed rape and ley seemed to have aslightly higher interception fraction for 85Sr at all growth stages. There was a positiverelationship for the biomass and interception fraction, for the LAI and interceptionfraction the relationship wasn’t significant. The retention showed a weak trend ofdecreasing with time, with the decrease being largest during the first day after theinterception. However, the standard deviation was large and consequently the values uncertain. / Utsläpp av radionuklider till atmosfären kan genom regn leda till att de våtdeponeras påväxter. Radionukliderna kan då fångas upp av växterna och hållas kvar vilket kanresultera i förhöjda halter av radioaktivitet hos växterna. Om detta leder till attgränsvärden överskrids kan kassering av växter som används vid livsmedelsproduktionvara nödvändig. Motåtgärder kan vidtas för att undvika kontaminering eller minskahalterna. För att veta vilka motåtgärder som ska användas är det viktigt att veta hurväxtens biomassa, bladyteindex (LAI), utvecklingsstadium samt väderförhållandenpåverkar uppfångningen och kvarhållningen. I detta arbete undersöktes uppfångningen och kvarhållningen av 134Cs och 85Sr hosvårvete, vall och vårraps. Inverkan av växtens biomassa, LAI och utvecklingsstadiumsamt nederbörd efter deponering undersöktes också. Arbetet genomfördes som ettfältförsök med försöksrutor med storleken 1 x 1 m. Växterna våtdeponerades med 134Csoch 85Sr med hjälp av en regnsimulator. En total aktivitet på 40 kBq/m2 för bådaradionukliderna deponerades per försöksruta. Deponeringar skedde under fyra olikaväxtutvecklingsstadier och växtprover togs ungefär fyra timmar efter deponering samtett och fem dygn senare. Aktiviteten hos de torkade växtproverna mättes med en HighPurity Germanium (HPGe) detektor. Därefter beräknades uppfångningsfraktioner ochkvarhållningsfaktorer. Försöket visade att uppfångningsfraktionen var störst vid det tredjeväxtutvecklingsstadiet för både vete och raps; degmognad för vete och fröutveckling förraps. Vallen, som slogs av efter två deponeringar, uppvisade störst uppfångningsfraktionvid andra växtutvecklingsstadiet, blomning. Hos raps och vall verkadeuppfångningsfraktionen för 85Sr vara något högre vid samtliga växtutvecklingsstadier.För biomassan och uppfångningsfraktionen fanns ett positivt samband, för LAI ochuppfångningsfraktionen var sambandet inte signifikant. Kvarhållningen visade en svagtrend att minska med tiden, minskningen var störst under det första dygnet efteruppfångningen. Dock var standardavvikelsen stor och värden därmed osäkra.

This master's thesis is an investigation and evaluation of MELCOR (a software tool for severe accident analyses regarding nuclear power plants), or more correctly of the (ASEA-Atom BWR 75) reactor model developed for version 1.8.6 of MELCOR. The main objective was to determine if MELCOR, with the reactor model in question, is able to produce satisfactory results in severe accident analyses compared to results made by MAAP, which is currently the only official software tool for this application in Sweden. The thesis work is related to the RASTEP project. This project has been carried out in several stages on behalf of SSM since 2009, with a number of specific issues explored within an NKS funded R&D project carried out 2011-2013. This investigation is related to the NKS part of the project. The purpose with the RASTEP project is to develop a method for rapid source term prediction that could aid the authorities in decision making during a severe accident in a nuclear power plant. A software tool, which also gave the project its name, i.e. RASTEP (RApid Source TErm Prediction), is therefore currently under development at Lloyd's Register Consulting. A software tool for severe accident analyses is needed to calculate the source terms which are the end result from the predictions made by RASTEP. A set of issues have been outlined in an earlier comparison between MAAP and MELCOR. The first objective was therefore to resolve these pre-discovered issues, but also to address new issues, should they occur. The existing MELCOR reactor model also had to be further developed through the inclusion of various safety systems, since these systems are required for certain types of scenarios. Subsequently, a set of scenarios was simulated to draw conclusions from the additions made to the reactor model. Most of the issues (pre-discovered as well as new ones) could be resolved. However the work also rendered a set of issues which are in need of further attention and investigation. The overall conclusion is that MELCOR is indeed a promising alternative for severe accident analyses in the Swedish work with nuclear safety. Several potential benefits from making use of MELCOR besides MAAP have been identified. In conclusion, they would be valuable assets to each other, e.g. since deviations in the results (between the two codes) would highlight possible weaknesses of the simulations. Finally it is recommended that the work on improving the MELCOR reactor model should continue. / RASTEP