Improvements in routine internal monitoring-- an overview of the IDEA project

Abstract

The IDEA project aimed to improve the assessment of incorporated radionuclides through developments of advanced in vivo and bioassay monitoring techniques and making use of such enhancements for improvements in routine monitoring. Many of these findings are not new in the sense that they are being already employed in advanced laboratories or for specialised applications. The primary goal was to categorise those new developments regarding their potential and eligibility for the routine monitoring community. Attention has been given to in vivo monitoring techniques with respect to detector characteristics and measurement geometry to improve measurement efficiency with special attention to low energy gamma emitters. Calibration-specifically supported by or through methods of numerical simulation-have been carefully analysed to reduce overall measurement uncertainties and explore ways to accommodate the individual variability based on characteristic features of a given person. For bioassay measurements at low detection limits, inductively coupled plasma mass spectroscopy offers significant advantages both in accuracy, speed, and sample preparation. Specifically, the determination of U and Th in urine and the associated models have been investigated. Finally, the scientific achievements have been analysed regarding their potential to offer benefits for routine monitoring. These findings will be presented in greater detail in other papers at this conference, whereas this paper intends to give an overview and put both the scientific achievements as well as the derived benefits into perspective.

Reassessment of 239Pu on planchets from human urine samples at ultra-trace levels using Aridus-ICPSFMS and AMS

“…AS measurements were performed with an Alpha Analyst Integrated Alpha Spectrometer (Canberra, TECNASA S.L., Spain) equipped with Passivated Implanted Planar Silicon detectors. These detectors have an active area of 450 mm 2 and their nominal alpha-peak energy resolution, expressed as full-width at half-maximum, is 18 keV. The planchets (Pu sources) were placed at 1.5 mm from the detector surface.…”

“…The successful measurement and assessment of internal exposure to radioactivity in dosimetry studies are highly dependent on the instrumental capabilities for measuring radionuclides in biological samples (urine, feces, blood or other secretions) (1,2) . Normally, during the Pu bioassay of human urine samples, it is mandatory to preconcentrate and purify the Pu fraction.…”

A highly sensitive method for the reassessment and quantification of 239Pu in urine samples based on a 1 MV accelerator mass spectrometry system

“…Internal exposure to Pu is principally assessed from in vitro measurements of the element excreted in urine, feces, blood or biological secretions. 2 The most common method is the bioassay of urine samples, which involves the processing of very large volumes of urine (typically 1.5-2 L), in order to obtain a concentrated and purified fraction of Pu that can be quantified by either Alpha-Spectrometry (AS) or Mass Spectrometry (MS) techniques.…”