Download or read book Gamma Ray Scanner Systems for Nondestructive Assay of Heterogeneous Waste Barrels written by and published by . This book was released on 1997 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Traditional gamma safeguards measurements have usually been performed using a segmented gamma scanning (SGS) system. The accuracy of this technique relies on the assumption that the sample matrix and the activity are both uniform for a segment. Waste barrels are often highly heterogeneous, span a wide range of composition and matrix type. The primary sources of error are all directly or indirectly related to a non-uniform measurement response associated with unknown radioactive source spatial distribution and heterogeneity of the matrix. These errors can be significantly reduced by some imaging techniques that measure exact spatial locations of sources and attenuation maps. In this paper we describe a joint R & D effort between the Lawrence Livermore National Laboratory (LLNL) and the Institute of Nuclear Techniques (INT) of the Technical University, Budapest, to compare results obtained by two different gamma-ray nondestructive assay (NDA) systems used for imaging waste barrels. The basic principles are the same, but the approaches are different. Key factors to judge the adequacy of a method are the detection limit and the accuracy. Test drums representing waste to be measured are used to determine basic parameters of these techniques.
Download or read book Application of Gamma ray Active and Passive Computed Tomography to Nondestructively Assay TRU Waste written by and published by . This book was released on 1996 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors have developed an active and passive computed tomography scanner for assaying radioactive waste drums. They describe the hardware and software components of the system used for data acquisition, gamma-ray spectroscopy analysis, and image reconstruction. They have measured the performance of the system using mock waste drums and calibrated radioactive sources. They describe the results of measurements using this system to assay a real TRU waste drum with relatively low Pu content.
Download or read book Frontiers of Engineering written by National Academy of Engineering and published by National Academies Press. This book was released on 1998-03-10 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Space may have been called the final frontier, but there are new frontiers to discover every day, and engineers are the ones exploring them. Through groundbreaking research and new technologies, engineers are able to go beyond traditional boundaries to do things that would have been all but impossible just a few years ago. This book, the most recent in a series of publications, describes new and emerging technologies and explains how they were developed and the benefits they will bring. It also offers highlights of the pioneering research and technological work being done by some of the country's emerging leaders in engineering. Topics include biomechanics, sensors and control for manufacturing processes, safety and security issues, decisionmaking tools for design and manufacturing, and intelligent transportation systems.
Download or read book Non destructive Assay of Drum Package Radioactive Wastes Utilizing Tomographic Gamma Scanning written by and published by . This book was released on 1996 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: A methodology for nondestructive assay of drum packaged radioactive waste materials is investigated using Emission Computed Tomography procedures. A requirement of this method is accurate gamma attenuation correction. This is accomplished by the use of a constant density distribution for the drum content, thereby requiring the need for a homogeneous medium. The current predominant NDA technique is the use of the Segmented Gamma Scanner. Tomographic Gamma Scanning improves upon this method by providing a low resolution three-dimensional image of the source distribution, yielding both spatial and activity information. Reconstruction of the source distribution is accomplished by utilization of algebraic techniques with a nine by six voxel model with detector information gathered over scanning intervals of ninety degrees. Construction of a linear system to describe the scenario was accomplished using a point-source response function methodology, where a 54 × 120 matrix contained the projected detector responses for each source-detector geometry. Entries in this matrix were calculated using the point-kernal shielding code QAD-CGGP. Validation was performed using the MCNP photon transport code. Solutions to the linear system were determined using the Non-Negative Least Squares (NNLS) algorithm and the LSMOD algorithm. A series of four scans were performed, each reconstructing the source distribution of a mock-up waste package containing a single 73 mCi 137Cs point source. For each scan, the source was located in a different location. Results of the reconstruction routines accurately predict the location and activity of the source. The range of activity calculated using the NNLS routine is 0.2681 mCi with an average value of 77.7995 mCi. The range of values calculated using LSMOD is 5.1843 mCi with an average of 72.8018 mCi.
Download or read book Proceedings of The 20th Pacific Basin Nuclear Conference written by Hong Jiang and published by Springer. This book was released on 2017-02-14 with total page 912 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the third in a series of three proceedings of the 20th Pacific Basin Nuclear Conference (PBNC). This volume covers the topics of Power Reactor and New Buildings, Waste Management, Acquiring Medical and Biological Benefits and Student program. As one in the most important and influential conference series of nuclear science and technology, the 20th PBNC was held in Beijing and the theme of this meeting was “Nuclear: Powering the Development of the Pacific Basin and the World”. It brought together outstanding nuclear scientist and technical experts, senior industry executives, senior government officials and international energy organization leaders from all across the world. The book serves as a useful reference not only for the professionals and public to know more about nuclear industry, but also for policymakers to adjust or make energy strategies.
Download or read book Radioactive Waste Management written by and published by . This book was released on 1981 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book GAMMA RAY SCANNING SYSTEM FOR BARRELS CONTAINING PLUTONIUM WASTE written by and published by . This book was released on 1972 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Annual Symposium on Frontiers of Engineering written by and published by . This book was released on 1998 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Field Experience with a Mobile Tomographic Nondestructive Assay System written by and published by . This book was released on 1995 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: A mobile tomographic gamma-ray scanner (TGS) developed by Los Alamos National Laboratory was recently demonstrated at the Rocky Flats Environmental Technology Site and is currently in use at Los Alamos waste storage areas. The scanner was developed to assay radionuclides in low-level, transuranic, and mixed waste in containers ranging in size from 2 ft3 boxes to 83-gallon overpacks. The tomographic imaging capability provides a complete correction for source distribution and matrix attenuation effects, enabling accurate assays of Pu-239 and other gamma-ray emitting isotopes. In addition, the system can reliably detect self-absorbing material such as plutonium metal shot, and can correct for bias caused by self-absorption. The system can be quickly configured to execute far-field scans, segmented gamma-ray scans, and a host of intermediate scanning protocols, enabling higher throughput (up to 20 drums per 8-hour shift). In this paper, we will report on the results of field trials of the mobile system at Rocky Flats and Los Alamos. Assay accuracy is confirmed for cases in which TGS assays can be compared with assays (e.g. with calorimetry) of individual packages within the drums. The mobile tomographic technology is expected to considerably reduce characterization costs at DOE production and environmental technology sites.
Download or read book Development of a Tomographic Instrument for Gamma ray Nondestructive Assay written by and published by . This book was released on 1993 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most widely used Transmission-corrected gamma-ray nondestructive assay (NDA) instruments is the Segmented Gamma Scanner (SGS) that was developed by the Los Alamos Nuclear Safeguards program in the early 1970s to determine the radioisotopic content of waste. SGS assays are accurate for low-density samples and also for high-density samples that are known to be uniform and homogeneous. However, for dense, heterogeneous samples, substantial bias is observed in SGS assays. To assay heterogeneous samples, knowledge of the distribution of emitting and attenuating materials is required. As a result we are developing a tomographic instrument to assay samples for which the assumptions of the SGS analysis are grossly violated. This instrument, known as the Tomographic Gamma Scanner (TGS), has the same basic components as the SGS, including a HPGE detector, a transmission source, and a mechanism to rotate and elevate the sample. However, an additional mechanical motion has been added that allows the detector to move in the direction transverse to the sample axis. This additional motion in combination with more stringent detector collimation enables the TGS to acquire, three-dimensional transmission and emission tomographic projection data from which the distributions of emitting and attenuating material can be determined. This spatial information provides a detailed correction for sample heterogeneities that results in more accurate assays. Our work on the development of the TGS has emphasized the role of the TGS as an NA instrument. Accurate determination of the quantity of emitting material is the primary goal. Precise determination of the distribution of emitting materials is a secondary and potentially conflicting objective. Consequently, desip considerations and analysis techniques differ from those of computerized tomography applied to medicine and nondestructive testing. An experimental TGS has been used to assay 208-l drums containing plutonium.
Download or read book Passive Nondestructive Assay of Nuclear Materials written by Doug Reilly and published by . This book was released on 1991 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Considerations for an Active and Passive Scanner to Assay Nuclear Waste Drums written by and published by . This book was released on 1990 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radioactive wastes are generated at many DOE laboratories, military facilities, fuel fabrication and enrichment plants, reactors, hospitals, and university research facilities. At all of these sites, wastes must be separated, packaged, categorized, and packed into some sort of container--usually 208-L (55-gal) drums--for shipment to waste-storage sites. Prior to shipment, the containers must be labeled, assayed, and certified; the assay value determines the ultimate disposition of the waste containers. An accurate nondestructive assay (NDA) method would identify all the radioisotopes present and provide a quantitative measurement of their activity in the drum. In this way, waste containers could be routed in the most cost-effective manner and without having to reopen them. Currently, the most common gamma-ray method used to assay nuclear waste drums is segmented gamma-ray scanning (SGS) spectrometer that crudely measures only the amount of 235U or 239Pu present in the drum. This method uses a spatially-averaged, integrated, emitted gamma-ray-intensity value. The emitted intensity value is corrected by an assumed constant-attenuation value determined by a spatially-averaged, transmission (or active) measurement. Unfortunately, this typically results in an inaccurate determination of the radioactive activities within a waste drum because this measurement technique is valid only for homogeneous-attenuation or known drum matrices. However, since homogeneous-attenuation matrices are not common and may be unknown, other NDA techniques based on active and Passive CT (A PCT) are under development. The active measurement (ACT) yields a better attenuation matrix for the drum, while the passive measurement (PCT) more accurately determines the identity of the radioisotopes present and their activities. 9 refs., 2 figs.
Download or read book Proceedings of the International Conference and Technology Exposition on Future Nuclear Systems Emerging Fuel Cycles and Waste Disposal Options Global 93 written by and published by . This book was released on 1993 with total page 724 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Institute of Energy and Climate Research IEK 6 Nuclear Waste Management Report 2011 2012 written by M. Klinkenberg and published by Forschungszentrum Jülich. This book was released on 2013 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Destructive Versus Nondestructive Assay Comparisons Using the SWEPP Gamma ray Spectrometer written by and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In support of data quality objectives for the INEEL Stored Waste Examination Pilot Plant (SWEPP) a series of 208-liter (55-gallon) waste drums containing inorganic sludge have been sampled and destructively analyzed. The drums were non-destructively assayed by the SWEPP PAN system and the SWEPP Gamma-Ray Spectrometer (SGRS) prior to sampling. This paper reports some of the conclusions from the destructive versus NDA comparisons, and additionally presents the results of an on-going effort to use the destructive analyses to validate absolute efficiency curves calculated using Monte-Carlo and analytical modeling for the SGRS. Destructive analysis results are available from radiochemical assay of 128 sludge-containing drums. The content codes represented are CC001 (42 items), CC002 (8), CC007 (48), CC800 (16), CC803 (3), and CC807 (11.) Each drum had two full-length vertical cores removed from designated radial positions. The entire length of each core was composited and submitted for analysis. All of the core composites were analyzed radiochemically for Am-241, Pu-239/240, and Pu-238, and by inductively-coupled mass spectrometry (ICPMS) for U-235 and U-238. Not only have the destructive analysis results been useful in documenting the performance of both the SGRS and the PAN system, but also have allowed the determination of certain absolute counting efficiency values for the SGRS. The values, in turn will allow us to validate SGRS counting efficiencies computed by MCNP and analytical modeling, and perhaps use the SGRS as an absolute assay technique.
Download or read book Multi isotopic Gamma ray Assay System for Alpha contaminated Waste written by and published by . This book was released on 1983 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The capability of an existing segmented gamma-ray system is being expanded for the analysis of alpha-contaminated waste drums. A cursory assay of 114 transuranic waste drums of 208-l capacity has been made. Analysis of these data indicates a detection limit better than 100 nCi/g of waste for 237Np/233Pa, 239Pu, 241Am, 243Am/239Np, 6°Co, 125Sb, 134 137Cs, and 154Eu. A pending Code of Federal Regulation (10CFR61) stipulates that the nuclear industry quantify not only its transuranic waste, but also certain beta- and gamma-ray-emitting fission products. An assay system based on gamma-ray spectroscopy is the only system that can meet this requirement for the fission products.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1994-12 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt:
