Download or read book Plutonium Isotopic Analysis of Highly Enriched Mixed Oxides written by Steven D. Clement and published by . This book was released on 1986 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nondestructive Assay of Mixed Uranium plutonium Oxides by Gamma ray Spectrometry written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Gamma-ray spectroscopy measurements have been made on mixed uranium and plutonium oxides in sealed containers to determine the uranium and plutonium enrichment and isotopics. Experimental results obtained using two different methods were in good agreement with the known contents. The first method is applicable to thick samples of freshly reprocessed mixed oxide and determines isotopic abundances from measured absolute gamma-ray intensities. Measurement times depend on plutonium enrichment, but for mixed oxide enriched to 12% in plutonium, the fissionable content can be determined to better than 0.5% in 2 h. The second approach utilizes intensity ratios of selected pairs of gamma-rays to determine plutonium enrichment and uranium and plutonium isotopes. This method requires at least 12 h to determine the plutonium enrichment to an accuracy of 0.5%. However, it cannot be applied until the 238U daughter activities in the mixed oxide reach equilibrium, which requires at least 5 months after separation. Preliminary conclusions drawn from these two noninvasive and nondestructive measurement techniques, and recommendations for future experiments are discussed.

Download or read book An Isotopic Analysis System for Plutonium Samples Enriched in Sup 238 Pu written by and published by . This book was released on 1991 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have designed and built a gamma-ray spectrometer system that measures the relative plutonium isotopic abundances of plutonium oxide enriched in 238Pu. The first system installed at Westinghouse Savannah River Company was tested and evaluated on plutonium oxide in stainless steel EP60/61 containers. 238Pu enrichments ranged from 20% to 85%. Results show that 200 grams of plutonium oxide in an EP60.61 container can be measured with {plus minus}0.3% precision and better than {plus minus}1.0% accuracy in the specific power using a counting time of 50 minutes. 3 refs., 2 figs.

Download or read book Model Plutonium Recycle Reactors for Environmental Analysis of the Mixed oxide Fuel Cycle written by J. W. Wachter and published by . This book was released on 1978 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Research Abstracts written by and published by . This book was released on 1992 with total page 824 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Neutronic Analysis of a Proposed Plutonium Recycle Assembly written by George Michael Solan and published by . This book was released on 1975 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: A method for the neutronic analysis of plutonium recycle assemblies has been developed with emphasis on relative power distribution prediction in the boundary area of vastly different spectral regions. Such regions are those of mixed oxide (Pu0 2 in natural U02 ) fuel pins relative to enriched uranium pins, or water regions relative to fuel pin regions. The basic analytical methods for determination of spectrum averaged constants are given in the following descriptions: (1) Generalized Mixed Number Density (GMND) group constants (based on Breen's Mixed Number Density Method) are generated by a modified version of the spectrum code LASER, called LASER-M. (2) THERMOS Corrected LASER-M (TCL) group constants are based on mixed oxide- uranium oxide and water region boundary modeling in one dimensional (slab) geometry with the integral transport code THERMOS. The LASER-M model, as modified by addition of ENDF/B-II thermal cross sections for the plutonium isotopes, is used to predict the criticality of experimental lattices of U02 - 2 w/o Pu0 2, and fair agreement is shown. LASER-M unit cell depletion calculations with Yankee Core I data (3.4 w/o U-235) to 40,000 MWD/MT and Saxton Core II data (6.6 w/o Pu02 in natural U02) to 20,000 MWD/MT show good isotopic agreement. Saxton Critical Reactor Experiment (CRX) lattice cores (19 x 19 rod array) consisting of a single fuel type region (mixed oxide or uranium oxide) or multiregions of both pin types were analyzed for relative power distribution comparisons. Cores with water slot regions were included. LASER-M Normal, LASER-M GMND and TCL two group constants were used with PDQ-7 in the calculations. GMND results were in excellent agreement compared to the good agreement of TCL for these cases of isolated spectral disturbances in an asymptotic core region. The methods were applied to a proposed plutonium recycle "island design" assembly in which a large control rod water region is in close proximity to a zoned mixed oxide region. The TCL method yielded significantly greater power peaking and mixed oxide region average power owing to the spectral influence of the water region explicitly accounted for in this method. Such a result is consistent with published calculations. It is concluded that infinite lattice spectrum calculations are insufficient to deal with spectrum effects more complex than those in the Saxton CRX experiments.

Download or read book Preparation and Certification of Highly Enriched Uranium Nitrate Solutions IRMM 3000 Series written by and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Directorate G "Nuclear Safety and Security", Unit G.2 "Standards for Nuclear Safety, Security and Safeguards" (SN3S) at the European Commission's Joint Research Centre, Geel in Belgium (formerly known as the "Institute for Reference Materials and Measurements" (IRMM)), provides a wide range of nuclear Certified Reference Materials (CRMs) to the safeguards authorities and the nuclear industry. This is an obligation under the Euratom treaty, where the need for isotope standards is explicitly mentioned, acknowledging their importance for the measurements of nuclear materials. For accurate mass spectrometric measurements in nuclear material accountancy and nuclear safeguards, suitable CRMs are needed to validate measurement procedures and to calibrate instruments. In particular, for mass spectrometry, CRMs are needed which have been prepared and characterized using procedures which are independent on mass spectrometric techniques as much as possible. One possible way to achieve this, is to use highly isotopically enriched starting materials and mix them under gravimetrical control in the correct proportions to achieve given targets for the isotope ratios. This procedure has been applied for the preparation of uranium and plutonium isotope CRMs for many years by several institutions, like NIST, NBL and IRMM/JRC-Geel. In the 1980s, the IRMM-072 series [7] of isotope mixtures containing 233U, 235U and 238U in various proportions was prepared based on this approach/method. About 20 years later, the isotope mixing program was restarted, and several further isotope CRMs were prepared and certified: the IRMM-074 [4] and IRMM-075 series [5], and the IRMM-3636a double spike [6]. In 2009, the IRMM-3000 series was prepared. It consists of a set of five highly enriched uranium nitrate solution reference materials named IRMM-3020, IRMM-3035, IRMM-3050, IRMM-3075 and IRMM-3090 with 235U enrichments varying from 20 % to 90 %. The solutions were prepared by dissolving uranium oxide (U3O8) materials, which were prepared by gravimetrically mixing oxides that are highly enriched in 235U and 238U. However, the verification measurements by TIMS showed some significant differences from the calculations based on the gravimetrical preparation. It was suspected that incomplete impurity analyses of the 238U starting material could be the cause for most of the differences, but this could not be confirmed at that time. Recently, the certification project for the IRMM-3000 series was restarted, including new mass spectrometric analyses of the isotope ratios performed at several laboratories and new impurity analysis for the 238U starting material.

Download or read book In Vivo Calibration Measurements for Mixed Oxide Nuclear Reactor Fuel written by and published by . This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The introduction of mixed oxide (MOX) nuclear fuel containing enriched uranium, isotopes of plutonium, and americium presents a challenge for monitoring occupational exposure using direct in vivo measurements because photons from (235)U and (241)Am will confound evaluation of plutonium in the lungs. MOX is a unique blend of enriched uranium and plutonium that can be used in place of traditional enriched uranium in commercial pressurized water reactors. The plutonium in MOX fuel may be derived from either surplus weapons-grade plutonium or reprocessed commercial nuclear fuel. Thus, the final isotopic composition of MOX depends upon the origin of the plutonium, how well chemical and radiological impurities are removed from the plutonium prior to fuel fabrication, the time between fuel fabrication and use, and (for spent fuel) the total time of irradiation in the reactor. These factors also will have a significant influence on the risk associated with occupational exposure to MOX and the optimum procedure for detecting MOX in vivo. Calibration of an array of high resolution detectors to perform in vivo measurements for MOX in the lungs was performed using the Lawrence Livermore thoracic phantom and a set of lungs containing a homogeneously distributed mixture of (238)U, (235)U, (241)Am, and (238)Pu to simulate conditions that might arise following inhalation of a typical MOX aerosol. Activity associated with photons from (235)U and (241)Am were easy to quantify. Low energy x-rays associated with plutonium decay were detected with reasonable certainty for a chest wall thickness below 3 cm after applying spectrum deconvolution to remove the interference from higher energy photons associated with (235)U and (241)Am. Analysis must depend upon low-abundant, higher energy plutonium photo peaks whenever chest wall thickness exceeds 3 cm because the low-energy uranium L x-rays are greatly attenuated by overlying muscle tissue in the anterior thorax. (7 tables, 7 fig, 11 re7.

Download or read book Publications of Los Alamos Research written by Los Alamos National Laboratory and published by . This book was released on 1986 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nonproliferation and Safeguards Aspects of Fuel Cycle Programs in Reduction of Excess Separated Plutonium and High enriched Uranium written by and published by . This book was released on 1995 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this preliminary investigation is to explore alternatives and strategies aimed at the gradual reduction of the excess inventories of separated plutonium and high-enriched uranium (HEU) in the civilian nuclear power industry. The study attempts to establish a technical and economic basis to assist in the formation of alternative approaches consistent with nonproliferation and safeguards concerns. Reference annual mass flows and inventories for a representative 1,400 Mwe Pressurized Water Reactor (PWR) fuel cycle have been investigated for three cases: the 100 percent uranium oxide UO2 fuel loading once through cycle, and the 33 percent mixed oxide MOX loading configuration for a first and second plutonium recycle. The analysis addresses fuel cycle developments; plutonium and uranium inventory and flow balances; nuclear fuel processing operations; UO2 once-through and MOX first and second recycles; and the economic incentives to draw-down the excess separated plutonium stores. The preliminary analysis explores several options in reducing the excess separated plutonium arisings and HEU, and the consequences of the interacting synergistic effects between fuel cycle processes and isotopic signatures of nuclear materials on nonproliferation and safeguards policy assessments.

Download or read book Rapid Nondestructive Plutonium Isotopic Analysis written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Methods for plutonium isotopic measurements have been evaluated for nuclear safeguards inventory verification. A mobile, real-time, nondestructive assay, gamma-ray spectrometric measurement system has been assembled, moved and operated at several nuclear storage facilities to perform rapid, real-time plutonium isotopic measurements on Pu metal, Pu nitrate and Pu oxide.

Download or read book Plutonium and Highly Enriched Uranium 1996 written by David Albright and published by . This book was released on 1997 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plutonium and highly enriched uranium (HEU) are the basic materials used in nuclear weapons. Plutonium also plays an important part in the generation of nuclear electricity. Knowing how much plutonium and HEU exists, where and in which form is vital for international security and nuclear commerce. This book is a thorough revision of the World Inventory of Plutonium and highly Enriched Uranium, 1992. It provides a rigorous and comprehensive assessment of the amounts of plutonium and HEU in military and civilian programmes, in nuclear and non-nuclear weapon states, and in countries seeking to acquire nuclear weapons. The capibilities that exist for producing these materials around the world are examined in depth, as are the policy issues raised by them. Containing much new information, this book is indispensable to all those concerned with the great contemporary issues in international nuclear relations: arms reductions in the nuclear weapon states, nuclear proliferation, nuclear smuggling, the roles of plutonium and enriched uranium in the nuclear fuel-cycle, and the disposition of surplus weapon material.

Download or read book Plutonium Isotopic Analysis System for Plutonium Samples Enriched in Sup 238 Pu in EP 60 61 and Fuel clad Containers written by and published by . This book was released on 1991 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: This user's manual is addressed to the Hanford Site personnel (routine operators and supervisors) who perform measurements with the Pu-238 isotopic analysis system. Each chapter begins with a table of contents that lists the section titles, illustrations, and tabular data presented in that chapter. The first chapter in this manual is an introduction to the system. Chapter 2 lists required settings for the system's commercial nuclear instrument modules. System operating procedures are given in Chapter 3. Chapter 4 contains routine and supervisorial operator interactions. Chapter 5 describes the system's short- and long-printout output formats. Chapter 6 gives instructions for changing system parameters. Error messages are listed and described in Chapter 7. Chapter 8 contains reference articles on measuring relative plutonium isotopics in solid samples.

Download or read book Plutonium Isotopic Analysis System for Plutonium Samples Enriched in Sup 238 Pu in EP 60 written by and published by . This book was released on 1991 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt: This software manual is addressed to the Westinghouse Hanford's Radioisotope Power Systems Facility personnel (programmers and supervisors) who maintain the software on the Pu-238 isotopic analysis system. The document is divided into two parts. Part 1 describes the computer codes that control the system, analyze the spectral data, and determine the relative plutonium abundances. Part 2 contains the software listing of the analysis codes.

Download or read book Complainte des prisonniers de ce temps sur le paraphrase du Liberame etc written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Plutonium Isotopic Analysis System for Plutonium Samples Enriched in Sup 238 Pu in EP 60 61 Containers written by and published by . This book was released on 1990 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: This user's manual is addressed to the Savannah River Site personnel (routine operators and supervisors) who perform measurements with the Pu-238 isotopic analysis system. Each chapter begins with a table of contents that lists the section title, illustrations, and tabular data presented in that chapter. The first chapter in this manual is an introduction to the system. Chapter 2 lists required settings for the system's commercial nuclear instrument modules. System operating procedures are given in Chapter 3. Chapter 4 contains routine and supervisorial operator interactions. Chapter 5 describes the system's short- and long-printout output formats. Chapter 6 gives instructions for changing system parameters. Error messages are listed and described Chapter 7. Chapter 8 contains a reference article on measuring relative plutonium isotopics in plutonium samples enriched in Pu-238. All commercial items mentioned in this manual are assumed to be functioning correctly for the purposes of system operation. Users are referred to individual equipment manufacturers' manuals for details of operation, trouble-shooting, and maintenance of this commercial equipment.

Download or read book Management and Disposition of Excess Weapons Plutonium written by National Academy of Sciences and published by National Academies Press. This book was released on 1995-08-06 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: Within the next decade, many thousands of U.S. and Russian nuclear weapons are slated to be retired as a result of nuclear arms reduction treaties and unilateral pledges. Hundreds of tons of plutonium and highly enriched uranium will no longer be needed for weapons purposes and will pose urgent challenges to international security. This is the supporting volume to a study by the Committee on International Security and Arms Control which dealt with all phases of the management and disposition of these materials. This technical study concentrates on the option for the disposition of plutonium, looking in detail at the different types of reactors in which weapons plutonium could be burned and at the vitrification of plutonium, and comparing them using economic, security and environmental criteria.