Reconstruction of the activity of point sources for the accurate characterization of nuclear waste drums by segmented gamma scanning

Krings, T.; Mauerhofer, Eric

doi:10.1016/j.apradiso.2011.02.009

Cited by 21 publications

(1 citation statement)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Industrial SGS systems for estimating the activity of 208-liter standard waste drums, declare on accuracy of 10-30% but with the worst case of up to 500% mistake [2]. A Recent method developed by [3] exploits the angular dependent count rate distribution and improved by [4], but requires long measurement time to get good counting statistics for the analysis. The goal of this work is to improve the accuracy results while reducing the total measurement time.…”

Section: Introductionmentioning

confidence: 99%

Improving Activity Estimation in Passive Gamma Scanning for Radioactive Waste Drums

Vax¹,

Marcus²,

Mazor³

et al. 2020

EPJ Web Conf.

View full text Add to dashboard Cite

A method to improve radioactive waste drum activity estimation in Segmented Gamma Scanning (SGS) systems was developed for homogenous content. We describe a method to quantify the activity of spatially distributed gamma-emitting isotopes (‘hot spots’) in homogenous content waste drums without the use of a collimator. Instead of averaging all the detector's readings we treat it as many different spatial samples as if we have multiple detectors surrounding the waste drum ("virtual detectors"). From these readings, we form a general linear model. Next, we derive the Maximum Likelihood Estimator (MLE) for the multiple sources position and activity. We solve this hyper-dimensional search problem using an Alternating Projections (AP) technique which transforms the problem into a simpler one-dimensional maximization problem. We tested this method using a mathematical simulation with a various number of sources, at random activities and positions for several energy bands. The preliminary results are consistent and show large improvement of the accuracy with comparison to industrial SGS systems and the same accuracy as new methods which exploits the spatial samples. Furthermore, since this method eliminates the need for heavy led collimator, none of the sources is blocked for the whole measurement period, which provides increased count rates and decreases the total measurement time.

show abstract

Section: Introductionmentioning

confidence: 99%

Improving Activity Estimation in Passive Gamma Scanning for Radioactive Waste Drums

Vax¹,

Marcus²,

Mazor³

et al. 2020

EPJ Web Conf.

View full text Add to dashboard Cite

show abstract

Efficiency Calculation of Gamma Detectors byMonteCarlo Methods

Sima

2012

Encyclopedia of Analytical Chemistry

View full text Add to dashboard Cite

γ‐Ray spectrometry is a powerful nondestructive multielemental analysis technique. Its quantitative application requires efficiency calibration. Among the methods available for the computation of the efficiency calibration curve, Monte Carlo simulation is ever increasing in popularity. The need for Monte Carlo simulation is the consequence of the inability of experimental calibration to cope with the broader scope and measuring configurations (shape, volume, and matrices of the samples), with the enhanced coincidence‐summing nuclide specific effects (favored by the current tendency to use high‐efficiency detectors) and with the desired performance parameters (detection limit and uncertainty) met in present‐day applications of γ‐ray spectrometry. The availability of a variety of Monte Carlo packages that can be applied to efficiency computation, several of them user friendly indeed, enlarged the class of potential users of this method. While experimental calibration remains the preferred method in the case of point sources and specific volume sources, such as solutions, it is the flexibility of Monte Carlo calculation that can provide a comprehensive calibration of γ‐ray detectors for a broad range of applications. In this article, the principles of Monte Carlo method are introduced, the applications to detector simulation are presented, and the solutions of typical problems in the calibration of γ‐spectrometry systems are reviewed.

show abstract

Analytical calculation of the collimated detector response for the characterization of nuclear waste drums by segmented gamma scanning

Qian

Krings

Mauerhofer

et al. 2012

J Radioanal Nucl Chem

View full text Add to dashboard Cite

Reconstruction of the activity of point sources for the accurate characterization of nuclear waste drums by segmented gamma scanning

Cited by 21 publications

References 19 publications

Improving Activity Estimation in Passive Gamma Scanning for Radioactive Waste Drums

Improving Activity Estimation in Passive Gamma Scanning for Radioactive Waste Drums

Efficiency Calculation of Gamma Detectors byMonteCarlo Methods

Analytical calculation of the collimated detector response for the characterization of nuclear waste drums by segmented gamma scanning

Contact Info

Product

Resources

About