Download or read book Comparison and Validation of HEU and LEU Modeling Results to HEU Experimental Benchmark Data for the Massachusetts Institute of Technology MITR Reactor written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Massachusetts Institute of Technology Reactor (MITR-II) is a research reactor in Cambridge, Massachusetts designed primarily for experiments using neutron beam and in-core irradiation facilities. It delivers a neutron flux comparable to current LWR power reactors in a compact 6 MW core using Highly Enriched Uranium (HEU) fuel. In the framework of its non-proliferation policies, the international community presently aims to minimize the amount of nuclear material available that could be used for nuclear weapons. In this geopolitical context, most research and test reactors both domestic and international have started a program of conversion to the use of Low Enriched Uranium (LEU) fuel. A new type of LEU fuel based on an alloy of uranium and molybdenum (UMo) is expected to allow the conversion of U.S. domestic high performance reactors like the MITR-II reactor. Towards this goal, comparisons of MCNP5 Monte Carlo neutronic modeling results for HEU and LEU cores have been performed. Validation of the model has been based upon comparison to HEU experimental benchmark data for the MITR-II. The objective of this work was to demonstrate a model which could represent the experimental HEU data, and therefore could provide a basis to demonstrate LEU core performance. This report presents an overview of MITR-II model geometry and material definitions which have been verified, and updated as required during the course of validation to represent the specifications of the MITR-II reactor. Results of calculations are presented for comparisons to historical HEU start-up data from 1975-1976, and to other experimental benchmark data available for the MITR-II Reactor through 2009. This report also presents results of steady state neutronic analysis of an all-fresh LEU fueled core. Where possible, HEU and LEU calculations were performed for conditions equivalent to HEU experiments, which serves as a starting point for safety analyses for conversion of MITR-II from the use of HEU fuel to the use of UMo LEU fuel.
Download or read book LEU HEU Mixed Core Conversion Thermal hydraulic Analysis and Coolant System Upgrade Assessment for the MIT Research Reactor written by Yinjie Zhao and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The MIT Research Reactor (MITR) is in the process of converting from the current 93%-enriched U-235 highly-enriched uranium (HEU) fuel to the low enriched uranium (LEU, 20%-enriched U-235) fuel, as part of the global non-proliferation initiatives. A high-density, monolithic uraniummolybdenum (U-10Mo) fuel matrix is chosen. The fuel element design is changed from 15-plate finned HEU fuel to 19-plate unfinned LEU fuel with the same geometry. The reactor power increases from 6.0 MW to 7.0 MW thermal, and primary coolant flow rate increases from 2000 gpm to 2400 gpm. Detailed analyses were completed for initial LEU core with 22 fuel elements, and demonstrated both neutronic and thermal hydraulic safety requirements are met throughout equilibrium cycles. An alternative conversion strategy is proposed which involves a gradual transition from an all-HEU core to an all-LEU core by replacing 3 HEU fuel elements with fresh LEU fuel elements during each fuel cycle. The objectives of this study are to demonstrate that the primary coolant system can be safely modified for 2400 gpm operation, and to perform steady-state and loss-of-flow (LOF) transient thermal-hydraulic analyses for the MITR HEU-LEU transitional mixed cores to evaluate this alternative conversion strategy. The primary technical challenge for the 20% increase in primary flow rate with existing piping system is flow-induced vibration. Several experiments were performed to measure and quantify vibration acceleration and velocity on three main hydraulic components to determine if higher flowrates cause excessive vibration. The test results show that the maximum vibration velocity is 9.70 mm/s, the maximum vibration acceleration is 0.98 G at the current flow rate 2000 gpm and no significant spectral change in the vibration profile at 2550 gpm. Therefore, it can be concluded that the existing piping system can safely support 2400 gpm primary flow operation. Thermal hydraulics analysis was performed using RELAP5 MOD3.3 code and STAT7 code. The MITR transitional mixed core input models were constructed to simulate the reactor primary system. Two scenarios, steady-state and loss-of-flow transient were simulated at power level of 6 MW. RELAP5 results show that during steady state, there is significant safety margin ( 10 °C) to onset of nucleate boiling for both HEU and LEU fuel. The maximum core temperature occurs at HEU fuel in Mix-core 3, the maximum wall temperature reached was 89 °C. During the LOF transient case, the result shows that The HEU fuel element is more limiting than the LEU in transitional cores. Nucleate boiling is predicted to occur only in the HEU hot channel during the first 50 seconds after the pump coastdown. The peak cladding temperatures are much lower than the fuel temperature safety limit of UAl[subscript x] fuel plates, which is 450 °C. From the STAT7 calculation results, the operational limiting power at which onset of nucleate boiling (ONB) occurs in all cases show significant margins from the Limiting System Safety Setting (LSSS) over-power level. The lowest margin for LEU element during the mixed core transition is at Mix-7, 11.43 MW with a 4.03 MW power margin. For the HEU element, the lowest margin during the transition is at Mix-2, 8.51 MW with a 1.11 MW power margin. The location at which ONB is always expected to occur is F-Plate Stripe 1 and 4 for the LEU fuel element; side plate for the HEU fuel element with the HEU element is always more limiting.
Download or read book Thermal Hydraulic Limits Analysis for the Massachusetts Institute of Technology Research Reactor Low Enrichment Uranium Core Conversion Using Statistical Propagation of Parametric Uncertainties written by Keng-Yen Chiang and published by . This book was released on 2012 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: The MIT Research Reactor (MITR) is evaluating the conversion from highly enriched uranium (HEU) to low enrichment uranium (LEU) fuel. In addition to the fuel element re-design from 15 to 18 plates per element, a reactor power upgraded from 6 MW to 7 MW is proposed in order to maintain the same reactor performance of the HEU core. Previous approaches in analyzing the impact of engineering uncertainties on thermal hydraulic limits via the use of engineering hot channel factors (EHCFs) were unable to explicitly quantify the uncertainty and confidence level in reactor parameters. The objective of this study is to develop a methodology for MITR thermal hydraulic limits analysis by statistically combining engineering uncertainties in order to eliminate unnecessary conservatism inherent in traditional analyses. This methodology was employed to analyze the Limiting Safety System Settings (LSSS) for the MITR LEU core, based on the criterion of onset of nucleate boiling (ONB). Key parameters, such as coolant channel tolerances and heat transfer coefficients, were considered as normal distributions using Oracle Crystal Ball for the LSSS evaluation. The LSSS power is determined with 99.7% confidence level. The LSSS power calculated using this new methodology is 9.1 MW, based on core outlet coolant temperature of 60 'C, and primary coolant flow rate of 1800 gpm, compared to 8.3 MW obtained from the analytical method using the EHCFs with same operating conditions. The same methodology was also used to calculate the safety limit (SL) to ensure that adequate safety margin exists between LSSS and SL. The criterion used to calculate SL is the onset of flow instability. The calculated SL is 10.6 MW, which is 1.5 MW higher than LSSS, permitting sufficient margin between LSSS and SL.
Download or read book Key Metrics for HFIR HEU and LEU Models written by Germina Ilas and published by . This book was released on 2016 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report compares key metrics for two fuel design models of the High Flux Isotope Reactor (HFIR). The first model represents the highly enriched uranium (HEU) fuel currently in use at HFIR, and the second model considers a low-enriched uranium (LEU) interim design fuel. Except for the fuel region, the two models are consistent and both include an experiment loading that is representative of HFIR's current operation.
Download or read book Key Metrics for HFIR HEU and LEU Models written by and published by . This book was released on 2016 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report compares key metrics for two fuel design models of the High Flux Isotope Reactor (HFIR). The first model represents the highly enriched uranium (HEU) fuel currently in use at HFIR, and the second model considers a low-enriched uranium (LEU) interim design fuel. Except for the fuel region, the two models are consistent and both include an experiment loading that is representative of HFIR s current operation. The considered key metrics are the neutron flux at the cold source moderator vessel, the mass of 252Cf produced in the flux trap target region as function of cycle time, the fast neutron flux at locations of interest for material irradiation experiments, and the reactor cycle length. These key metrics are a small subset of the overall HFIR performance and safety metrics. They were defined as a means of capturing data essential for HFIR s primary missions, for use in optimization studies assessing the impact of HFIR s conversion from HEU fuel to different types of LEU fuel designs.
Download or read book Comparison of Calculated and Measured Irradiated Wire Data for HEU and Mixed HEU written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Low power wire activations are being performed in the Oak Ridge Research Reactor (ORR) as part of the whole-core LEU demonstration experiments. Calculations of the demonstration cores, including simulation of the wire activations, are being performed at Argonne National Laboratory (ANL). This paper presents the results of comparisons for 293 wires from five cores and shows that, on the average, the integrated activities agree within 6%.
Download or read book Measurements of the HEU and LEU In core Spectra at the Ford Nuclear Reactor written by and published by . This book was released on 1984 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Ford Nuclear Reactor (FNR) at the University of Michigan has been serving as the test site for a low-enriched uranium (LEU) fuel whole-core demonstration. As part of the experimental program, the differential neutron spectrum has been measured in a high-enriched uranium (HEU) core and an LEU core. The HEU and LEU spectra were determined by unfolding the measured activities of foils that were irradiated in the reactor. When the HEU and LEU spectra are compared from 1 MeV to 10 MeV, significant differences between the two spectra are apparent below 10 eV. These are probably caused by the additional 238U resonance absorption in the LEU fuel. No measurable difference occurs in the shape of the spectra above 1 MeV. 7 refs., 6 figs., 2 tabs.
Download or read book Thermal Hydraulic Analyses of the HEU and the Proposed LEU Core Configurations of the UMass Lowell Research Reactor written by A. Amarnath and published by . This book was released on 1993 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molybdenum 99 for Medical Imaging written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2016-11-28 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: The decay product of the medical isotope molybdenum-99 (Mo-99), technetium-99m (Tc-99m), and associated medical isotopes iodine-131 (I-131) and xenon-133 (Xe-133) are used worldwide for medical diagnostic imaging or therapy. The United States consumes about half of the world's supply of Mo-99, but there has been no domestic (i.e., U.S.-based) production of this isotope since the late 1980s. The United States imports Mo-99 for domestic use from Australia, Canada, Europe, and South Africa. Mo-99 and Tc-99m cannot be stockpiled for use because of their short half-lives. Consequently, they must be routinely produced and delivered to medical imaging centers. Almost all Mo-99 for medical use is produced by irradiating highly enriched uranium (HEU) targets in research reactors, several of which are over 50 years old and are approaching the end of their operating lives. Unanticipated and extended shutdowns of some of these old reactors have resulted in severe Mo-99 supply shortages in the United States and other countries. Some of these shortages have disrupted the delivery of medical care. Molybdenum-99 for Medical Imaging examines the production and utilization of Mo-99 and associated medical isotopes, and provides recommendations for medical use.
Download or read book Guide to Nuclear Power Cost Evaluation Equipment costs written by Kaiser Engineers and published by . This book was released on 1962 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Space Nuclear Propulsion for Human Mars Exploration written by National Academies of Sciences Engineering and Medicine and published by . This book was released on 2021-11-12 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Space Nuclear Propulsion for Human Mars Exploration identifies primary technical and programmatic challenges, merits, and risks for developing and demonstrating space nuclear propulsion technologies of interest to future exploration missions. This report presents key milestones and a top-level development and demonstration roadmap for performance nuclear thermal propulsion and nuclear electric propulsion systems and identifies missions that could be enabled by successful development of each technology.
Download or read book A New Approach to the Nuclear Fuel Cycle written by Kelsey Hartigan and published by Rowman & Littlefield. This book was released on 2015-02-23 with total page 81 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Nuclear Threat Initiative and the Center for Strategic and International Studies joined to launch the New Approaches to the Fuel Cycle project. This project sought to build consensus on common goals, address practical challenges, and engage a spectrum of actors that influence policymaking regarding the nuclear fuel cycle. The project also tackled one of the toughest issues—spent nuclear fuel and high level waste—to see if solutions there might offer incentives to states on the front end of the nuclear fuel cycle and address the inherent inertia and concerns about additional burdens and restrictions that have stalled past efforts to improve the robustness of the nonproliferation regime. This report presents the group’s conclusions that a best-practices approach to the nuclear fuel cycle can achieve these objectives and offer a path to a more secure and sustainable nuclear landscape.
Download or read book Material Properties of Unirradiated Uranium Molybdenum U Mo Fuel for Research Reactors written by International Atomic Energy Agency and published by . This book was released on 2020-10-12 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication presents the material properties of all unirradiated Uranium-Molybdenum (U-Mo) fuel constituents that are essential for fuel designers and reactor operators to evaluate the fuel's performance and safety for research reactors. Many significant advances in the understanding and development of low enriched uranium U-Mo fuels have been made since 2004, stimulated by the need to understand irradiation behavior and early fuel failures during testing. The publication presents a comprehensive overview of mechanical and physical property data from U-Mo fuel research
Download or read book Knowledge Based Intelligent Information and Engineering Systems written by Ignac Lovrek and published by Springer Science & Business Media. This book was released on 2008-08-18 with total page 1079 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation The three volume set LNAI 5177, LNAI 5178, and LNAI 5179, constitutes the refereed proceedings of the 12th International Conference on Knowledge-Based Intelligent Information and Engineering Systems, KES 2008, held in Zagreb, Croatia, in September 2008. The 316 revised papers presented were carefully reviewed and selected. The papers present a wealth of original research results from the field of intelligent information processing in the broadest sense; topics covered in the first volume are artificial neural networks and connectionists systems; fuzzy and neuro-fuzzy systems; evolutionary computation; machine learning and classical AI; agent systems; knowledge based and expert systems; intelligent vision and image processing; knowledge management, ontologies, and data mining; Web intelligence, text and multimedia mining and retrieval; and intelligent robotics and control.
Download or read book Neutron Capture Therapy written by Wolfgang A.G. Sauerwein and published by Springer Science & Business Media. This book was released on 2012-11-05 with total page 545 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neutron capture therapy (NCT) is based on the ability of the non-radioactive isotope boron-10 to capture thermal neutrons with very high probability and immediately to release heavy particles with a path length of one cell diameter, which in principle allows for tumor cell-selective high-LET particle radiotherapy. This book provides a comprehensive summary of the progress made in NCT in recent years. Individual sections cover all important aspects, including neutron sources, boron chemistry, drugs for NCT, dosimetry, and radiation biology. The use of NCT in a variety of malignancies and also some non-malignant diseases is extensively discussed. NCT is clearly shown to be a promising modality at the threshold of wider clinical application. All of the chapters are written by experienced specialists in language that will be readily understood by all participating disciplines.
Download or read book Energy Systems Drives and Automations written by Afzal Sikander and published by Springer. This book was released on 2021-09-01 with total page 725 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gathers selected research papers presented at the Second International Conference on Energy Systems, Drives and Automations (ESDA 2019), held in Kolkata on 28–29 December 2019. It covers a broad range of topics in the fields of renewable energy, power management, drive systems for electrical machines and automation. Also discussing a variety of related tools and techniques, the book offers a valuable resource for researchers, professionals and students in electrical and mechanical engineering disciplines.
Download or read book Radiation Safety in Well Logging written by IAEA and published by International Atomic Energy Agency. This book was released on 2020-08-18 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Safety Guide provides recommendations on the use of radioactive sources and radiation generators in well logging, including in the manufacture, calibration and maintenance of well logging tools. It provides recommendations on radiation protection and safety for the storage, use and transport of such radiation sources. The guidance in this publication is aimed primarily at operating organizations that are authorized to undertake well logging with radiation sources, as well as their employees and radiation protection officers. The guidance will also be of interest to regulatory bodies, and to designers, manufacturers, suppliers, and maintenance and servicing organizations of well logging equipment that contains radiation sources.
