Browsing by Subject "Radiochemistry"

Measurement of alpha-active actinides requires separation from other alpha emitting radionuclides. A method of actinide separation was needed for the primary coolant water of Loviisa Nuclear Power Plant. A method published by Eichrom Ltd was chosen to be evaluated, this method utilises a vacuum box with stacked TEVA / TRU columns which speeds up and eases the analysis process. The method can be used to separate americium, curium, plutonium and uranium from a water samples and it gave excellent results both with reference samples and primary coolant water. The separation was also tested with other more difficult matrices: ion exchange resins, surface swipes, aerosol filters and process waste waters. Pretreatment methods for these matrices were assessed and tested to reduce the sample to a soluble form that could be loaded to the separation system. DGA resin based methods were tested for both gross-alpha and nuclide specific analyses. The gross-alpha method with DGA was fast, efficient and reliant. Gross alpha counting samples could be produced within hours and element fraction samples could be produced in 1 - 2 days. This combined with the good recoveries of all fractions meant shorter counting times to reach the minimal detectable activities (MDAs) required. The literature review part takes a look into recent interesting topics related to actinide separation and analysis from similar matrices discussed in the the experimental section. Different extraction chromatography resins are discussed.