scholarly journals Metrological Assurance for Radioactive Waste Monitors Based on HPGe Detectors

2018 ◽  
pp. 47-53
Author(s):  
F. V. Finkel ◽  
А. J. Kail ◽  
А. D. Sokolov ◽  
V. V. Gostilo
Keyword(s):  
Radioactive Waste ◽  
Simulation Method ◽  
Accounting System ◽  
Position Change ◽  
Bar Code ◽  
Russian Research Institute ◽  
Activity Measurements ◽  
Hpge Detectors ◽  
Measured Activity

The methods of calibration and parameters measurements of radioactive waste monitors with the purpose to provide the unity and required precision of the characterization of waste activity measurements are reviewed. The monitors based on HPGe detectors are intended for small, medium and large volumes of radioactive waste and are equipped with rotation mechanisms for the barrel with strain-gauge balance and actuator for horizontal shifting, dosimeters for dose rate measurement, software and accounting system by bar code. The required range of the measured activity which is necessary for the operation of the spectrometric section without overloadings is ensured by removal or approaching of the barrel to the detector and position change of the vertical lead shields of the collimator. The rotation of the barrel with RAW ensures decreasing the measurement error at the presence of the heterogeneities by density of the filler and inequalities of activity distribution by the barrel volume. The monitors have different mechanisms and accessories for the measurements in various modes. The calibration of the monitors by the registration efficiency is performed using standard sources in point geometry as well as by the complex calculation of the efficiencies curves by Monte Carlo simulation method. For calibration of the monitors by the method of direct comparison the volumetric activities sources in real 200, 400 and 700 l barrels with matrix-fillers placed inside were manufactured and certified. The manufactured volumetric measures of activity have been certificated at the All-Russian Research Institute of Metrology named after D. I. Mendeleev. An integral part of the metrological support of all developed RAWmonitors is their software, features of which are being considered.

An Automated Non-Destructive Assay System for the Measurement and Characterization of Radioactive Waste

2003 ◽  
Author(s):  
J. A. Mason ◽  
W. Hage ◽  
R. Price ◽  
A. C. Tolchard ◽  
A. C. N. Towner
Keyword(s):  
Radioactive Waste ◽  
Dose Rate ◽  
Matrix Effects ◽  
Fissile Material ◽  
Surface Dose ◽  
Heavy Duty ◽  
Bar Code ◽  
Non Destructive ◽  
Waste Drums

The paper describes an automated non-destructive assay (NDA) system for the measurement and characterization of radioactive waste. The Waste Characterisation System (WCS) can be adapted to measure a variety of drum sizes: 60, 220 (55 gallon) and 440 liter, the latter with a maximum weight of 1500 kg (1.5 tonnes). The NDA system includes a Tomographic Segmented Gamma Scanner (TSGS) and an active/passive neutron Differential Die-away (DDA or DDT). The system can assay a wide variety of waste types in a range of waste matrices. The assay stations are linked by a heavy duty roller conveyor which incorporates a 20 drum buffer store, a load cell (built into the conveyor), bar code readers and a dose rate measurement station. The Tomographic Segmented Gamma Scanner (TSGS) combines conventional high resolution gamma spectrometry and a tranission source to interrogate a waste drum in vertical slices (segments) as for Segmented Gamma Scanner (SGS) measurements. However, in the case of the TSGS, while the drum is rotated, it is also moved in the horizontal direction leading to an enhanced ability to correct the gamma ray energies, from the nuclides of interest, for the attenuation of the matrix. The TSGS can also be operated as a conventional SGS for the measurement of homogeneous waste drums. The DDA is a very sensitive active neutron interrogation method that uses thermalised neutrons from a pulsed source within the chamber to irradiate a waste drum. Prompt neutrons from fissile material present in the waste (e. g. 239Pu, 235U) are detected and provide a measure of the fissile content in the drum. In passive mode, the DDA determines the even Pu nuclides exhibiting significant spontaneous fission (e.g. 240Pu). Measurement accuracy depends on correction algorithms to compensate for self-shielding and matrix effects in waste drums containing hydrogenous materials. In addition, the DDA will be provided with the Fission-Fission Neutron Correlation Analysis System (FFnC) which is an absolute technique eliminating the need for matrix dependent mass calibrations, and allowing separate U and Pu determination using delayed neutron counting. The FFnC technique will be tested for the first time on the WCS. The NDA system incorporates integrated stations to determine the weight and dose rate of each drum, the former built into the conveyor the latter as part of the TSGS. Six Geiger Muller tubes measure the surface dose at three positions on the drum side, one at 1 metre from the drum and one each measuring the surface dose of the top and bottom of the drum. The assay instruments are linked to a heavy duty conveyor system onto which up to 20 waste drums can be loaded for delivery to the various measurement stations, thus permitting unattended, automated operation. Once measured, the drums remain on the conveyer in a holding system waiting to be unloaded. Automation is provided using a programmable logic controller (PLC) and associated computers. A central computer and associated software is used for data acquisition and management.

scholarly journals The development of waste assay monitors based on the HPGe detectors

2018 ◽  
Vol 33 (4) ◽  
pp. 411-416
Author(s):  
Aleksandr Sokolov ◽  
Artjom Kail ◽  
Feliks Finkel ◽  
Vladimir Gostilo
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Radioactive Waste ◽  
Simulation Method ◽  
Monte Carlo Simulation Method ◽  
Volumetric Activity ◽  
Verification Method ◽  
Direct Verification ◽  
Hpge Detectors ◽  
Complex Calculation

The results from the development and the evaluation of radioactive waste monitors for small, medium, and large volumes of those wastes are presented. The efficiency calibration of monitors was made using the standard sources in point geometry as well as by using the complex calculation of the efficiency curves using the Monte Carlo simulation method. The volumetric activity sources were manufactured in the form of real 200, 400, and 700 litre barrels with matrix-fillers in order to calibrate the monitors using the direct verification method. The peculiarities of the software that controls the monitors are presented.

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.

Operating Temperature Analysis of LED with Cylindrical Cu Slug

2014 ◽  
Vol 487 ◽  
pp. 145-148 ◽  
Author(s):  
Rajendaran Vairavan ◽  
Zaliman Sauli ◽  
Vithyacharan Retnasamy
Keyword(s):  
Natural Convection ◽  
Operating Temperature ◽  
Simulation Method ◽  
Input Power ◽  
Junction Temperature ◽  
Temperature Analysis ◽  
Light Emitting ◽  
New Era ◽  
Lighting Systems

High power light emitting diodes is the new era of lighting due to momentous supremacy in terms of lighting efficacy over traditional lighting systems. The reliability of LED is dependent on its junction temperature. This study confers on the thermal and stress characterization of LED chip with copper cylindrical heat slug through simulation method. The simulation characterization was carried out with Ansys version 11 at ambient temperature of 25°C under natural convection condition. The LED package was powered with input powers of 0.1 W, 0.5 W and 1W .Results indicated that input power influences the junction temperature and stress of LED chip.

Sign in / Sign up

Export Citation Format

Share Document