scholarly journals The efficiency calibration for local manufacturing gamma scanning systems of radioactive waste drums

2018 ◽  
Vol 15 (35) ◽  
pp. 100-108
Author(s):  
Saad Salih Dawood
Keyword(s):  
Radioactive Waste ◽  
Radioactive Source ◽  
Assay Method ◽  
Nondestructive Assay ◽  
Local Manufacturing ◽  
Cylindrical Holes ◽  
Scanning Systems ◽  
Waste Drums ◽  
Gamma System ◽  
Gamma Scanning

The Local manufacturing scanning gamma system designed in Tuwaitha site for nondestructive assay method of radioactive waste drums, where it consist of two main parts with their belongings for controlling the of detector and drum movements up-down and rotation respectively. The volume of the used drum is 220 L with 85 cm height. The drum filled with Portland cement. Six cylindrical holes were made within cement drum and distributed in radial arrangement.The152Eu source inserted in these holes individually, to measure the average angular count rate of gamma radiation. The full energy efficiency value for geometry of drum and detector is computed for thirteen photo peaks. The average efficiency represented by the curve of these peaks indicated the decreasing of efficiency value with increasing the cement thickness and the distance between the detector and the location of radioactive source inside the drum.

Collimator-Less Passive Gamma Scanning for Radioactive Waste Drums

2020 ◽  
Vol 67 (4) ◽  
pp. 544-551
Author(s):  
Eran Vax ◽  
Eliezer Marcus ◽  
Tzahi Mazor ◽  
Yagil Kadmon ◽  
Alon Osovizky
Keyword(s):  
Radioactive Waste ◽  
Waste Drums ◽  
Gamma Scanning

Do We Accurately Know the Radioactive Inventory Inside a Waste Package? A Résumé After 5 Years Experience in the Development and Operation of Advanced Gamma Scanning Systems

2001 ◽  
Author(s):  
H.-J. Sanden ◽  
G. Caspary ◽  
K. Kroth ◽  
M. Bruggeman ◽  
T. Bücherl
Keyword(s):  
Quality Control ◽  
Radioactive Waste ◽  
Gamma Ray ◽  
Source Distribution ◽  
Research Projects ◽  
Waste Package ◽  
Gamma Ray Attenuation ◽  
The Difference ◽  
Scanning Systems ◽  
Gamma Scanning

Abstract This paper gives a survey of the main results of research projects performed by members of ENTRAP to improve gamma-ray scanning techniques for radioactive waste packages. Performance characteristics, advantages and restrictions of different assay procedures and correction techniques investigated in these projects are discussed. Case studies are presented which demonstrate the difference in performance between ‘standard’ and ‘improved’ assay techniques. Consideration is also given to bias effects resulting from a limited knowledge on gamma-ray attenuation and/or source distribution in the waste matrix. Procedures and tools are presented which may help to decrease respective bias effects or to assess the overall uncertainty. The achievements emphasise that quality control of assay results requires, in nearly all applications, that additional assay techniques are implemented in order to verify the validity of conventional gamma-ray scanning methods.

Semi-Tomographic Gamma Scanning Technique for Non-Destructive Assay of Radioactive Waste Drums

2016 ◽  
Vol 63 (6) ◽  
pp. 2793-2800 ◽  
Author(s):  
Weiguo Gu ◽  
Kaiyuan Rao ◽  
Dezhong Wang ◽  
Jiemei Xiong
Keyword(s):  
Radioactive Waste ◽  
Scanning Technique ◽  
Non Destructive ◽  
Waste Drums ◽  
Gamma Scanning

Application of computer assisted tomography (CAT) to gamma attenuation measurement of soil water content

Soil Research ◽  
1988 ◽  
Vol 26 (1) ◽  
pp. 105 ◽  
Author(s):  
JM Hainsworth ◽  
LAG Aylmore
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Computer Assisted ◽  
Scanning System ◽  
Advantages And Disadvantages ◽  
Computer Assisted Tomography ◽  
Scanning Systems ◽  
Gamma System ◽  
Gamma Scanning

This paper demonstrates the successful application of computer assisted tomography (CAT) to �-ray attenuation measurements and the modification of a conventional gamma scanning system to enable changes in the spatial distribution of soil water content to be accurately monitored in soil columns. The relatively inexpensive gamma system has been shown to provide a resolution comparable to that obtainable with commercially available but extremely expensive X-ray CAT scanning systems. However, longer counting times are required with gamma radiation, thus limiting the usefulness of the technique for some soil water studies. A comparison of the efficiency of several source-detection combinations illustrates their relative advantages and disadvantages.

scholarly journals Improving Activity Estimation in Passive Gamma Scanning for Radioactive Waste Drums

2020 ◽  
Vol 225 ◽  
pp. 06010
Author(s):  
E. Vax ◽  
E. Marcus ◽  
T. Mazor ◽  
Y. Kadmon ◽  
A. Osovizky
Keyword(s):  
Radioactive Waste ◽  
Maximization Problem ◽  
Search Problem ◽  
Multiple Sources ◽  
Energy Bands ◽  
Spatially Distributed ◽  
Total Measurement Time ◽  
Waste Drums ◽  
Activity Estimation ◽  
Gamma Scanning

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.

scholarly journals SiLiF Neutron Counters to Monitor Nuclear Materials in the MICADO Project

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2630
Author(s):  
Luigi Cosentino ◽  
Quentin Ducasse ◽  
Martina Giuffrida ◽  
Sergio Lo Meo ◽  
Fabio Longhitano ◽  
...  
Keyword(s):  
Radioactive Waste ◽  
Detector Response ◽  
Nuclear Materials ◽  
Spent Fuel ◽  
Neutron Detectors ◽  
Intermediate Level Radioactive Waste ◽  
Eu Project ◽  
Interim Storage ◽  
Waste Drums

In the framework of the MICADO (Measurement and Instrumentation for Cleaning And Decommissioning Operations) European Union (EU) project, aimed at the full digitization of low- and intermediate-level radioactive waste management, a set of 32 solid state thermal neutron detectors named SiLiF has been built and characterized. MICADO encompasses a complete active and passive characterization of the radwaste drums with neutrons and gamma rays, followed by a longer-term monitoring phase. The SiLiF detectors are suitable for the monitoring of nuclear materials and can be used around radioactive waste drums possibly containing small quantities of actinides, as well as around spent fuel casks in interim storage or during transportation. Suitable polyethylene moderators can be exploited to better shape the detector response to the expected neutron spectrum, according to Monte Carlo simulations that were performed. These detectors were extensively tested with an AmBe neutron source, and the results show a quite uniform and reproducible behavior.

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