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  • Author or Editor: K. Olsen x
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Abstract  

A method for the separation and determination of total and isotopic uranium and plutonium by ICP/MS was developed for IAEA samples on cellulose-based media. Preparation of the IAEA samples involved a series of redox chemistries and separations using TRU® resin (Eichrom). The sample introduction system, an APEX nebulizer (Elemental Scientific, Inc.), provided enhanced nebulization for a several-fold increase in sensitivity and reduction in background. Application of mass bias (ALPHA) correction factors greatly improved the precision of the data. By combining the enhancements of chemical separation, instrumentation and data processing, detection levels for uranium and plutonium approached high attogram levels.

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Abstract  

Electrochemically modulated separations (EMS) are shown to be a rapid and selective means of extracting and concentrating Pu from complex solutions prior to isotopic analysis by inductively coupled plasma mass spectrometry (ICP‐MS). This separation is performed in a flow injection mode, on‐line with the ICP‐MS. A three‐electrode, flow‐by electrochemical cell is used to accumulate Pu at an anodized glassy carbon electrode by redox conversion of Pu(III) to Pu (IV&VI). The entire process takes place in 2% (v/v) (0.46 M) HNO3. No redox chemicals or acid concentration changes are required. Plutonium accumulation and release is redox dependent and controlled by the applied cell potential. Large transient volumetric concentration enhancements can be achieved. Based on more negative U(IV) potentials relative to Pu(IV), separation of Pu from uranium is efficient, thereby eliminating uranium hydride interferences. EMS‐ICP‐MS isotope ratio measurement performance will be presented for femtogram to attogram level plutonium isotope injections.

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The objective of this paper is to investigate consumer attitudes and behavioural patterns related to fish consumption in Poland and four Western European countries (Belgium, Denmark, the Netherlands, and Spain). A quantitative cross-sectional consumer survey was carried out and a total sample of 4786 respondents, representative within each country for age and region (n=800–1100 respondents per country) was obtained. Although Polish consumers have the most positive general attitudes toward fish and the strongest belief that eating fish is healthy and safe, their intention and fish consumption is on a very low level compared to the Western European countries.

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Abstract  

Characterization of transuranic waste is needed for decisions about waste site remediation. Soil-gas sampling for xenon isotopes can be used to define the locations of spent fuel and transuranic waste. Radioxenon in the subsurface is characteristic of transuranic waste and can be measured with extreme sensitivity using large-volume soil-gas samples. Measurements at the Hanford Site showed 133Xe and 135Xe levels indicative of 240Pu spontaneous fission. Stable xenon isotopic ratios from fission are distinct from atmospheric xenon background. Neutron capture by 135Xe produces an excess of 136Xe in reactor-produced xenon, providing a means of distinguishing spent fuel from separated transuranic material.

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