Estimation of Measurement Uncertainty for 230Th Radioisotope Analysis in Soil

Year 2019, NSP2018 Special Issue, 165 - 173, 28.03.2019

Meryem Seferinoğlu , Pınar Esra Erden

Abstract

The
uncertainty of a measurement is the interval of values within which the true
value is believed to lie with a stated probability when all sources of error
have been taken into account and is therefore represents the reliability of a
measurement. In this study, we evaluate the measurement uncertainty in the determination
of ²³⁰Th in the soil sample using a radiochemical separation
procedure and alpha spectrometry. All the sources in the analysis method that
contribute to the combined uncertainty were identified. The uncertainty
associated with a certain parameter was used to determine its partial
contribution to the combined standard uncertainty of the measurand. The spreadsheet
and full matematical approach was used to present the combined standard
uncertainty. 

Keywords

Measurement Uncertainty, Thorium Isotopes, Alpha Spectrometry

References

• Vreček P., Benedik L., “Evaluation of measurement uncertainty in the determination of 210Pb and 210Po using beta counting and alpha spectrometry” Accred. Qual. Assur. 8, 134-137 (2003).
• Heydorn, K., “Evaluation of the uncertainty of environmental measurements of radioactivity” Journal of Radioanalytical and Nuclear Chemistry. 262, No. 1 249-253 (2004).
• ISO, 1995. “ISO Guide to the expression of uncertainty in measurement” International Organization for Standardization, Geneva,ISBN:92-67r-r10188-9 (Available online from http://www.bipm.org/en/publications/guides/gum.html)
• Guimarães Couto, P. R., Damasceno, C. D., and Pinheiro de Oliveira, S., “Monte Carlo Simulations Applied to Uncertainty in Measurement” Theory and Applications of Monte Carlo Simulations. Chapter 2, 27-51, DOI: 10.5772/53014.
• Modna, D. K., Jerome, S. M., White, M. A., Woods, M. J., “Thorium in workplace measurement intercomparison”. Applied Radiation isotopes, 53, 265-271 (2000).
• Jia, G., Torri, G., Ocone, R., Di Lullo, A., De Angelis, A., & Boschetto, R., “Determination of thorium isotopes in mineral and environmental water and soil samples by α-spectrometry and the fate of thorium in water” Applied Radiation and Isotopes, 66 (10), 1478-1487, (2008).
• Eichrom Technologies, LLC Method No: ACW10VBS Analytical Procedure Revision: 1.1 May 1, 2014
• Eichrom Technologies, LLC Method No: ACW03 Analytical Procedure Revision: 2.2 May 1, 2014
• Kanisch, G., “Alpha-spectrometric analysis of environmental samples” (IAEA-TEC-DOC-1401). Quantifying Uncertainty in Nuclear Analytical Measurements. International Atomic Energy Agency, Vienna, pp. 127–139 (2004).
• Holmes, L., “Alpha Spectrometric Analysis of Environmental Samples Spreadsheet approach” (IAEA-TEC-DOC-1401) Quantifying Uncertainty in Nuclear Analytical Measurements. International Atomic Energy Agency, Vienna, pp. 114–149 (2004).