Download or read book Non destructive Assay of Drum Package Radioactive Wastes Utilizing Tomographic Gamma Scanning written by Kelly L. Ausbrooks and published by . This book was released on 1996 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 LANL s Mobile Nondestructive Assay and Examination Systems for Radioactive Wastes 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 ability to accurately and rapidly measure nuclear material within drums and examine their contents without having to unpack the drums saves time, reduces characterization costs and minimizes radiation exposure. Over the past two years, Los Alamos National Laboratory (LANL) has developed and fielded a suite of mobile nondestructive assay and examination systems for use primarily on its own transuranic (TRU) waste but that also have application to low level, mixed and hazardous wastes. It has become obvious that systems like these are generally useful and have applications at other Department of Energy (DOE) production and environmental technology sites. Mobile capabilities present a potential cost savings where waste drums have to be transported to a fixed NDA facility. In other cases they fill a void where there is no fixed facility available because construction costs are prohibitive (as in the case of small quantity sites) or the available facilities may not meet current or evolving safety standards. Rather than bringing waste to a facility to be characterized, one can bring the characterization capability to the waste. The three systems described are: (1) mobile radiography system; (2) mobile segmented/tomographic gamma scanner; and (3) mobile passive/active neutron assay system.
Download or read book Precision Estimates for Tomographic Nondestructive Assay written by and published by . This book was released on 1995 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Requirements for effective safeguards during the transition to environmental management at nuclear material production facilities within the DOE complex are deriving improvements in the accuracy of nondestructive assay (NDA) techniques. An important aspect of the transition is the need for facilities to terminate safeguards on waste materials, thus reducing the cost for safeguards at the facility. Requirements for the termination of safeguards on candidate waste material have been established by DOE to minimize the potential for diversion or theft of nuclear material. Because heterogenous waste and residue materials are stored in large containers such as 208-L drums, conventional assay techniques such as segmented gamma scanning (SGS) that were developed to assay small samples cannot always provide accurate measurements. Consequently, facilities using the conventional NDA instrumentation may be limited in their ability to discard waste materials in compliance with DOE requirements. One technique being applied to improve the accuracy of assays of waste in large containers is computerized tomography (CT). Research on the application of CT to improve both neutron and gamma-ray assays of waste is being carried out at Los Alamos National Laboratory. For example, tomographic gamma scanning (TGS) is a single-photon emission CT technique that corrects for attenuation of gamma rays emitted from the sample using attenuation images from transmission CT.
Download or read book Nondestructive Assay Using Active and Passive Computed Tomography written by and published by . This book was released on 1998 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: The United States Department of Energy (DOE) has over 600,000 transuranic (TRU) waste drums temporarily stored at nearly 40 sites within the United States. Contents of these drums must be characterized before they are transported for permanent disposal. Traditional gamma-ray methods used to characterize nuclear waste introduce errors that are related to nonuniform measurement responses associated with unknown radioactive source and matrix material distributions. These errors can be reduced by application of tomographic techniques, that measure these distributions. The Lawrence Livermore National Laboratory (LLNL) has developed two tomographic-based waste assay systems. They use external radioactive sources and tomography-protocol to map the attenuation within a waste drum as a function of mono-energetic gamma-ray energy in waste containers. Passive tomography is used to localize and identify specific radioactive waste contents within the same waste containers. Reconstruction of the passive data via the active images allows internal waste radioactivities in a drum to be corrected for any overlying heterogeneous materials, thus yielding an absolute assay of the waste radioactivities. Calibration of both systems requires only point source measurements and are independent of matrix materials. The first system is housed at LLNL and was developed to study and validate research concepts. The second system is being developed with Bioimaging Research, Inc. (BIR) and is housed within a mobile waste characterization trailer. This system has traveled to three DOE facilities to demonstrate the active and passive computed tomography capability. Both systems have participated in and successfully passed the requirements of formal DOE-sponsored intercomparison studies. The systems have measured approximately 1 to 100 grains of plutonium within a variety of waste matrix materials. Laboratory and field results from these two systems over the past several years show that both systems are capable of a precision of 1 to 4% and an accuracy of better than 30% of the true values of known standards for all drums measured.
Download or read book Characterization of Waste Drums Using Nonintrusive Active and Passive Computed Tomography written by and published by . This book was released on 1994 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have developed a data acquisition scanner for gamma-ray nondestructive assay (NDA) active and passive computed tomography (A & PCT) along with associated computational techniques for image reconstruction, analysis, and display. We are using this scanner to acquire data sets of mock-waste drums at Lawrence Livermore National Laboratory (LLNIL). In this paper, we discuss some issues associated with gamma-ray spectroscopy assay, NDA imaging, describe the design and construction of an NDA drum scanner and report on code development for image reconstruction. We also present representative A & PCT assay results of well characterized mock-waste drums. These preliminary results suggest that A & PCT imaging can be used to produce accurate absolute assays of radioactivity in real-waste drums.
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 Strategy and Methodology for Radioactive Waste Characterization written by International Atomic Energy Agency and published by IAEA. This book was released on 2007 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past decade significant progress has been achieved in the development of waste characterization and control procedures and equipment as a direct response to ever-increasing requirements for quality and reliability of information on waste characteristics. Failure in control procedures at any step can have important, adverse consequences and may result in producing waste packages which are not compliant with the waste acceptance criteria for disposal, thereby adversely impacting the repository. The information and guidance included in this publication corresponds to recent achievements and reflects the optimum approaches, thereby reducing the potential for error and enhancing the quality of the end product. -- Publisher's description.
Download or read book Award Winning System Assays Radiation Waste With Radiation written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: More than half a million drums of radioactive waste are stored at 30 Department of Energy sites across the nation, with thousands more to come as facilities at weapons complex sites are dismantled. All of these drums must be assayed to determine and verify their contents and levels of radioactivity so they can be transported for permanent storage or disposal. A system that assays containers of radioactive waste safely, accurately, and nonintrusively has garnered a prestigious R and D 100 Award--presented annually by R and D Magazine to ''the 100 most technologically significant new products and processes of the year''--for Lawrence Livermore National Laboratory and its commercial partner, Bio-Imaging Research, Inc. (BIR) from Lincolnshire, Illinois. The award-winning Waste Inspection Tomography for Non-Destructive Assay (WIT-NDA) system was developed by a team of engineers and physicists headed by Livermore's Patrick Roberson and Harry Martz. The system combines active and passive computed tomography and nuclear spectroscopy to accurately quantify all detectable gamma rays emitted from waste containers. The WIT-NDA is part of BIR's Waste Inspection Tomography system, which provides nondestructive examination and assay of radioactive waste and has been commercially available since August 1999. ''The WIT-NDA is an excellent example of successful technology transfer between a DOE national laboratory and a small private business'', says Richard Bernardi, WIT program manager for BIR.
Download or read book Standard Test Method for Nondestructive Assay of Radioactive Material by Tomographic Gamma Scanning written by and published by . This book was released on with total page 0 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 Waste Inspection Tomography WIT written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: WIT is a self-sufficient mobile semitrailer for nondestructive evaluation and nondestructive assay of nuclear waste drums using x-ray and gamma-ray tomography. The recently completed Phase I included the design, fabrication, and initial testing of all WIT subsystems installed on-board the trailer. Initial test results include 2 MeV digital radiography, computed tomography, Anger camera imaging, single photon emission computed tomography, gamma-ray spectroscopy, collimated gamma scanning, and active and passive computed tomography using a 1.4 mCi source of[sup 166]Ho. These techniques were initially demonstrated on a 55-gallon phantom drum with 3 simulated waste matrices of combustibles, heterogeneous metals, and cement using check sources of gamma active isotopes such as[sup 137]Cs and[sup 133]Ba with 9-250[mu]Ci activities. Waste matrix identification, isotopic identification, and attenuation-corrected gamma activity determination were demonstrated nondestructively and noninvasively in Phase I. Currently ongoing Phase II involves DOE site field test demonstrations at LLNL, RFETS, and INEL with real nuclear waste drums. Current WIT experience includes 55 gallon drums of cement, graphite, sludge, glass, metals, and combustibles. Thus far WIT has inspected drums with 0-20 gms of[sup 239]Pu.
Download or read book Tomographic Gamma Scanning of Uranium contaminated Waste at Rocky Flats written by and published by . This book was released on 1998 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: A tomographic gamma-ray scanning (TGS) instrument was deployed at Rocky Flats Environmental Technology Site (RFETS) to assist with the deactivation of Building 886. Many 208-L drums containing waste contaminated with highly enriched uranium were measured in order to certify these sites for shipment and disposal. This project marks a successful cooperation between RFETS and Los Alamos National Laboratory and is the first major field experience using TGS technology to assay uranium.
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 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Traditional gamma measurement errors are related to non-uniform measurement responses associated with unknown radioactive source and matrix material distributions. These errors can be reduced by application of tomographic techniques that measure these distributions. LLNL has developed two tomographic-based waste assay systems. They use external radioactive sources and tomography-protocol to map the attenuation within a waste barrel as a function of mono-energetic gamma-ray energy in waste containers. Passive tomography is used to localize and identify specific radioactive waste contents within the same waste containers. Reconstruction of the passive data via the active images allows internal waste radioactivities in a barrel to be corrected for any overlying heterogeneous materials, thus yielding an absolute assay of the waste radioactivities. Calibration of both systems requires only point source measurements and are independent of matrix materials.
Download or read book Radioactive Waste Management written by and published by . This book was released on 1981 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Results of a Comparison Study Using Tomographic and Segmented Gamma Scanner Technology written by and published by . This book was released on 2004 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to support the many on-going research and programmatic activities at Los Alamos Plutonium and Chemistry and Metallurgy Research (CMR) Facilities in as accurate, efficient, and cost-effective manner possible, every reasonable effort is made to equip the nondestructive assay (NDA) laboratories with the most modern and technologically advanced instrumentation available. Recently, new state-of-the-art tomographic gamma scanner (TGS) instruments were installed to replace aging and outmoded segmented gamma scanner (SGS) instruments. Through the implementation of a translation axis, in addition to the vertical and rotation axes of the SGS, the TGS technique is able to employ axial tomography to determine the spatial distribution and quantity of nuclear material using high-resolution gamma-ray spectroscopy. Because the attenuation matrix and source distributions are known more accurately than with the SGS technology, biases due to matrix and source distributions should be reduced. In principle, a single calibration should suffice for the determination of isotopic mass for a wide range of material and matrix types. A number of questions naturally arise concerning these purported advantages of the TGS. Perhaps the most fundamental of these is to understand how the TGS measurement results compare with those of a typical SGS on the same well-characterized standards differing in matrix and material type. To that end, the TGS operating parameters were optimized to assay 55-gallon drum waste identical to that measured by our SGS. The calibration and measurement results on these standards, placed in typical low-density waste matrices, are presented and discussed. These results should enable more confident use of the TGS as well as point the way toward even more studies to enable more effective employment of the new TGS technology.
