Author: W. D. Ruhter Publisher: ISBN: Category : Languages : en Pages :
Book Description
The gamma-ray data analysis methodology originally developed for the MGA code to determine the relative detection efficiency curve may also be used to determine the relative amounts of the isotopes being measured. This analysis approach is based on the fact that the intensity of any given gamma ray from a sample is determined by the amount of the emitting isotope present in the sample, the emission probability for the gamma ray being measured, the sample self attenuation, the attenuation due to absorbers between the sample and detector, and the detector efficiency. An equation can be written that describes a measured gamma-ray peak intensity in terms of these parameters. By selecting appropriate gamma-ray peaks from the isotopes of interest, we can solve a set of equations for the values of the parameters in any particular measurement including the relative amounts of the selected isotopes. The equations representing the peak intensities are very nonlinear and require an iterative least squares method to solve. We have developed software to ensure that during the iterative process the parameters stay within their appropriate ranges and converge properly in solving the set of equations under various measurement conditions. We have utilized and reported on this approach for determining the plutonium isotopic abundances in samples enriched in Pu-238 and to determine the U-235 enrichment of uranium samples in thick-walled containers. Recently, we have used this approach to determine the plutonium isotopic abundances of plutonium samples in thick-walled containers. We will report on this most recent application, and how this general approach can be adapted quickly to any isotopic analysis problem.
Author: Publisher: ISBN: Category : Languages : en Pages : 7
Book Description
The goal of the generalized gamma-ray analysis software is to provide precise and accurate isotopic analyses of samples that do not have a standard experimental geometry. This analysis tool will analyze gamma-ray data from all types of measurement scenarios with little or no interaction from the user. This tool also provides complete transparency regarding the gamma-ray peaks and branching intensities used in the analysis with the capability for the user to modify this information. They are currently at the data collected phase of building a validated spectral library. One of the by-products in this data collection phase is enabling them to reevaluate the two important branching ratios in 242Pu. These branching ratios are required for very high burn-up plutonium fuels. The preliminary analysis shows that the energy of the states are 103.5 keV and 158.82 keV, the branching ratio are 1.36E-5 (9%) and 3.37E-6(7%), respectively. More accurate measurements and analysis are currently being carried out.
Author: Publisher: ISBN: Category : Languages : en Pages :
Book Description
We discuss the general approach, computerized data analysis methods, and results of measurements used to determine the isotopic composition of plutonium by gamma-ray spectroscopy. The simple techniques are designed to be applicable to samples of arbitrary size, geometry, age, chemical, and isotopic composition. The combination of the gamma spectroscopic measurement of isotopic composition coupled with calorimetric measurement of total sample power is shown to give a totally nondestructive determination of sample plutonium mass with a precision of 0.6% for 1000-g samples of PuO2 with 12% 24°Pu content. The precision of isotopic measurements depends upon many factors, including sample size, sample geometry, and isotopic content. Typical ranges are found to be 238Pu, 1 to 10%; 239Pu, 0.1 to 0.5%; 24°Pu, 2 to 5%; 241Pu, 0.3 to 0.7%; 242Pu (determined by isotopic correlation); and 241Am, 0.2 to 10%.
Author: International Atomic Energy Agency. Nuclear Fuel Cycle and Materials Section Publisher: ISBN: 9789201083036 Category : Science Languages : en Pages : 173
Author: Publisher: ISBN: Category : Languages : en Pages :
Book Description
This report describes a computer-based gamma spectrometer system that was developed for measuring isotopic and total plutonium concentrations in nitric acid solutions. The system was installed at the Tokai reprocessing plant where it is undergoing testing and evaluation as part of the Tokai Advanced Safeguards Exercise (TASTEX). Objectives of TASTEX Task H, High-Resolution Gamma Spectrometer for Plutonium Isotopic Analysis, the methods and equipment used, the installation and calibration of the system, and the measurements obtained from several reprocessing campaigns are discussed and described. In general, we find that measurements for gamma spectroscopy agree well with those of mass spectrometry and of other chemical analysis. The system measures both freshly processed plutonium from the product accountability tank and aged plutonium solutions from storage tanks. 14 figures, 15 tables.
Author: Publisher: ISBN: Category : Languages : en Pages : 32
Book Description
This report describes the development history and characteristics of software developed in the Safeguards Science and Technology group at Los Alamos for gamma-ray isotopic analysis. This software analyzes the gamma-ray spectrum from measurements performed on actinide samples (principally plutonium and uranium) of arbitrary size, geometry, and physical and chemical composition. The results are obtained without calibration using only fundamental tabulated nuclear constants. Characteristics of the current software versions are discussed in some detail and many examples of implemented measurement systems are shown.
Author: W. D. Ruhter
Author: 
Author: 
Author: 
Author: 
Author: 
Author: International Atomic Energy Agency. Nuclear Fuel Cycle and Materials Section
Author: 
Author: 
Author: Doug Reilly