Analyses Supporting Conversion of Research Reactors from High Enriched Uranium Fuel to Low Enriched Uranium Fuel

Analyses Supporting Conversion of Research Reactors from High Enriched Uranium Fuel to Low Enriched Uranium Fuel PDF Author: International Atomic Energy Agency
Publisher:
ISBN: 9789201018182
Category : Technology & Engineering
Languages : en
Pages : 0

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Book Description
This publication was developed based on the results of an IAEA coordinated research project (CRP) and will serve as a reference to those potentially involved in conversion of research reactors from high enriched uranium (HEU) to low enriched uranium (LEU). The publication contains comprehensive design and safety analyses for the conversion of miniature neutron source reactors (MNSRs) and includes analyses that were performed by MNSR operating organizations participating in the CRP using data specific to their MNSR. The outcome of this CRP can therefore be used to provide best practice guidelines in preparation for conversion of research reactors by individual research reactor operating organizations, and as a procedural and methodological reference for regulatory bodies and other stakeholders involved in the conversion of research reactors.

Analyses Supporting Conversion of Research Reactors from High Enriched Uranium Fuel to Low Enriched Uranium Fuel

Analyses Supporting Conversion of Research Reactors from High Enriched Uranium Fuel to Low Enriched Uranium Fuel PDF Author: International Atomic Energy Agency
Publisher:
ISBN: 9789201018182
Category : Technology & Engineering
Languages : en
Pages : 0

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Book Description
This publication was developed based on the results of an IAEA coordinated research project (CRP) and will serve as a reference to those potentially involved in conversion of research reactors from high enriched uranium (HEU) to low enriched uranium (LEU). The publication contains comprehensive design and safety analyses for the conversion of miniature neutron source reactors (MNSRs) and includes analyses that were performed by MNSR operating organizations participating in the CRP using data specific to their MNSR. The outcome of this CRP can therefore be used to provide best practice guidelines in preparation for conversion of research reactors by individual research reactor operating organizations, and as a procedural and methodological reference for regulatory bodies and other stakeholders involved in the conversion of research reactors.

Reducing the Use of Highly Enriched Uranium in Civilian Research Reactors

Reducing the Use of Highly Enriched Uranium in Civilian Research Reactors PDF Author: National Academies of Sciences, Engineering, and Medicine
Publisher: National Academies Press
ISBN: 0309379210
Category : Science
Languages : en
Pages : 205

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Book Description
The continued presence of highly enriched uranium (HEU) in civilian installations such as research reactors poses a threat to national and international security. Minimization, and ultimately elimination, of HEU in civilian research reactors worldwide has been a goal of U.S. policy and programs since 1978. Today, 74 civilian research reactors around the world, including 8 in the United States, use or are planning to use HEU fuel. Since the last National Academies of Sciences, Engineering, and Medicine report on this topic in 2009, 28 reactors have been either shut down or converted from HEU to low enriched uranium fuel. Despite this progress, the large number of remaining HEU-fueled reactors demonstrates that an HEU minimization program continues to be needed on a worldwide scale. Reducing the Use of Highly Enriched Uranium in Civilian Research Reactors assesses the status of and progress toward eliminating the worldwide use of HEU fuel in civilian research and test reactors.

Conversion of Research and Test Reactors to Low-enriched Uranium (LEU) Fuel

Conversion of Research and Test Reactors to Low-enriched Uranium (LEU) Fuel PDF Author: United States. Congress. House. Committee on Science and Technology. Subcommittee on Energy Development and Applications
Publisher:
ISBN:
Category : Nuclear engineering
Languages : en
Pages : 1968

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Book Description


Progress, Challenges, and Opportunities for Converting U.S. and Russian Research Reactors

Progress, Challenges, and Opportunities for Converting U.S. and Russian Research Reactors PDF Author: Russian Academy of Sciences
Publisher: National Academies Press
ISBN: 0309253209
Category : Science
Languages : en
Pages : 126

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Book Description
Highly enriched uranium (HEU) is used for two major civilian purposes: as fuel for research reactors and as targets for medical isotope production. This material can be dangerous in the wrong hands. Stolen or diverted HEU can be used-in conjunction with some knowledge of physics-to build nuclear explosive devices. Thus, the continued civilian use of HEU is of concern particularly because this material may not be uniformly well-protected. To address these concerns, the National Research Council (NRC) of the U.S. National Academies and the Russian Academy of Sciences (RAS) held a joint symposium on June 8-10, 2011. Progress, Challenges, and Opportunities for Converting U.S. and Russian Research Reactors summarizes the proceedings of this joint symposium. This report addresses: (1) recent progress on conversion of research reactors, with a focus on U.S.- and R.F.-origin reactors; (2) lessons learned for overcoming conversion challenges, increasing the effectiveness of research reactor use, and enabling new reactor missions; (3) future research reactor conversion plans, challenges, and opportunities; and (4) actions that could be taken by U.S. and Russian organizations to promote conversion. The agenda for the symposium is provided in Appendix A, biographical sketches of the committee members are provided in Appendix B, and the report concludes with the statement of task in Appendix C.

Conversion and Evaluation of the University of Massachusetts Lowell Research Reactor From High-Enriched To Low-Enriched Uranium Fuel

Conversion and Evaluation of the University of Massachusetts Lowell Research Reactor From High-Enriched To Low-Enriched Uranium Fuel PDF Author: Leo M. Bobek
Publisher:
ISBN:
Category :
Languages : en
Pages : 5

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Book Description
The process for converting the University of Massachusetts Lowell Research Reactor (UMLRR) from high-enrichment uranium (HEU) fuel to low-enrichment uranium (LEU) fuel began in 1988. Several years of design reviews, computational modeling, and thermal hydraulic analyses resulted in a preliminary reference core design and configuration based on 20 standard, MTR-type, flat-plate, 19.75% enriched, uranium silicide (u3Si2) fuel elements. A final safety analysis for the fuel conversion was submitted to the Nuclear Regulatory Commission (NRC) in 1993. The NRC made two additional requests for additional information and supplements were submitted in 1994 and 1997. The new UMLRR Reactor Supervisor initiated an effort to change the LEU reference core configuration to eliminate a complicated control rod modification needed for the smaller core.

Medical Isotope Production Without Highly Enriched Uranium

Medical Isotope Production Without Highly Enriched Uranium PDF Author: National Research Council
Publisher: National Academies Press
ISBN: 0309130395
Category : Medical
Languages : en
Pages : 220

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Book Description
This book is the product of a congressionally mandated study to examine the feasibility of eliminating the use of highly enriched uranium (HEU2) in reactor fuel, reactor targets, and medical isotope production facilities. The book focuses primarily on the use of HEU for the production of the medical isotope molybdenum-99 (Mo-99), whose decay product, technetium-99m3 (Tc-99m), is used in the majority of medical diagnostic imaging procedures in the United States, and secondarily on the use of HEU for research and test reactor fuel. The supply of Mo-99 in the U.S. is likely to be unreliable until newer production sources come online. The reliability of the current supply system is an important medical isotope concern; this book concludes that achieving a cost difference of less than 10 percent in facilities that will need to convert from HEU- to LEU-based Mo-99 production is much less important than is reliability of supply.

Accident Analyses for Conversion of the University of Missouri Research Reactor (MURR) from Highly-Enriched to Low-Enriched Uranium

Accident Analyses for Conversion of the University of Missouri Research Reactor (MURR) from Highly-Enriched to Low-Enriched Uranium PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
This report contains the results of reactor accident analyses for the University of Missouri Research Reactor (MURR). The calculations were performed as part of the conversion from the use of highly-enriched uranium (HEU) fuel to the use of low-enriched uranium (LEU) fuel. The analyses were performed by staff members of the Global Threat Reduction Initiative (GTRI) Reactor Conversion Program at the Argonne National Laboratory (ANL), the MURR Facility, and the Nuclear Engineering Program - College of Engineering, University of Missouri-Columbia. The core conversion to LEU is being performed with financial support from the U.S. government. This report contains the results of reactor accident analyses for the University of Missouri Research Reactor (MURR). The calculations were performed as part of the conversion from the use of highly-enriched uranium (HEU) fuel to the use of low-enriched uranium (LEU) fuel. The analyses were performed by staff members of the Global Threat Reduction Initiative (GTRI) Reactor Conversion Program at the Argonne National Laboratory (ANL), the MURR Facility, and the Nuclear Engineering Program - College of Engineering, University of Missouri-Columbia. The core conversion to LEU is being performed with financial support from the U.S. government. In the framework of 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 LEU fuel. A new type of LEU fuel based on an alloy of uranium and molybdenum (U-Mo) is expected to allow the conversion of U.S. domestic high performance reactors like MURR. This report presents the results of a study of core behavior under a set of accident conditions for MURR cores fueled with HEU U-Alx dispersion fuel or LEU monolithic U-Mo alloy fuel with 10 wt% Mo (U-10Mo).

Conversion from High Enriched Uranium Fuel to Low Enriched Uranium Fuel for the University of Lowell Research Reactor

Conversion from High Enriched Uranium Fuel to Low Enriched Uranium Fuel for the University of Lowell Research Reactor PDF Author: John E. Stoddard
Publisher:
ISBN:
Category : Nuclear fuels
Languages : en
Pages : 320

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Book Description


Impact of Fuel Density on Performance and Economy of Research Reactors

Impact of Fuel Density on Performance and Economy of Research Reactors PDF Author: IAEA
Publisher: International Atomic Energy Agency
ISBN: 9201205201
Category : Technology & Engineering
Languages : en
Pages : 118

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Book Description
Research reactor fuel technology continues to evolve, driven in part by international efforts to develop high density fuels to enable the conversion of more reactors from highly enriched uranium (HEU) to low enriched uranium (LEU) fuels. These high density fuels may offer economic benefits for research reactors, despite being more expensive initially, because they offer the prospect of higher per-assembly burnup, thus reducing the number of assemblies that must be procured, and more flexibility in terms of spent fuel management compared to the currently qualified and commercially available LEU silicide fuels. Additionally, these new fuels may offer better performance characteristics. This publication provides a preliminary evaluation of the impacts on research reactor performance and fuel costs from using high density fuel. Several case studies are presented and compared to illustrate these impacts.

Impact Assessment for the MIT Research Reactor Low Enrichment Uranium Fuel Fabrication Tolerances

Impact Assessment for the MIT Research Reactor Low Enrichment Uranium Fuel Fabrication Tolerances PDF Author: Dakota J. Allen
Publisher:
ISBN:
Category :
Languages : en
Pages : 109

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Book Description
In the framework of non-proliferation policy, the Massachusetts Institute of Technology Reactor (MITR) is planning to convert from highly enriched uranium (HEU) to low enriched uranium (LEU) fuel. A new type of high-density LEU fuel based on a monolithic U-10Mo alloy is being qualified to allow the conversion of all remaining U.S. high performance research reactors including the MITR. The purpose of this study is to understand the impact of proposed MITR LEU "FYT" fuel element fabrication tolerances on the operation and safety limits of the MITR. Therefore, the effects of fabrication specification parameters on all levels of the core, ranging from full-core alterations to individual spots on the fuel plates were analyzed. Evaluations at the design tolerances, and beyond, were conducted through neutronics and thermal hydraulics calculations. The first step was analyzing the separate effects that parameters, including enrichment, fuel mass loading, fuel plate thickness, and impurities, have on the reactor physics of the core. These analyses were used to develop curve fits to predict the effect of these parameters on the excess reactivity of fresh fuel inserted into the LEU core. These models could then be used to estimate the effect on fuel cycle length to ensure the tolerances would not cause significant changes to the operating cycle of MITR. These analyses estimated the margin to criticality present in the core and ensured that the reactivity shutdown margin (SDM) was not violated. Other parameters such as coolant channel gap and local fuel homogeneity cause primarily local impacts including the power distribution within the fuel element, and related impacts to thermal hydraulic margins. This modeling was necessary to ensure that these parameters would not cause the margin to MITR's thermal hydraulic safety limit, the onset of nucleate boiling (ONB), to be violated. The final step was a covariance analysis of the combined effects at a full-core and element level. This combined effect analysis assured that the core would maintain proper safety and operational margins with a realistic distribution of off-nominal parameters. Given the comprehensive analysis performed, the current design fabrication tolerances were determined to provide acceptable fuel cycle length and safety margins consistent with the MITR LEU preliminary safety analysis report, and a basis for updating these tolerances during planned manufacturing-scale plate fabrication demonstrations has been established.