Nuclear Commons^™

Non-Dipolar Electron Angular Distributions From Fixed-In-Space Molecules, Renaud Guillemin, Oliver Hemmers, Dennis W. Lindle, E. Shigemasa, K. Le Guen, D. Ceolin, C. Miron, N. Leclercq, P. Morin, Marc Simon, P. W. Langhoff

Environmental Studies Faculty Publications

The first indication of nondipole effects in the azimuthal dependence of photoelectron angular distributions emitted from fixed-in-space molecules is demonstrated in N₂. Comparison of the results with angular distributions observed for randomly oriented molecules and theoretical derivations for the nondipole correction first order in photon momentum suggests that higher orders will be needed to describe distributions measured in the molecular frame.

Development Of A Model For Induction Heating, Randy Clarksean, Yitung Chen

Fuels Campaign (TRP)

There are two coupled equations that must be solved in order to determine the power deposition. The numerical solution of these equations is needed in order to apply a source term within the energy equations. These equations have previously solved in FIDAP. That implementation used modified versions of the momentum and energy equations to provide a mechanism for the solution of two coupled equations. Currently, we want to solve for the induction heating field in addition to the flow field and the energy equation. In order to do this, a mechanism has to be defined within FIDAP to solve these …

Development Of Dose Coefficients For Radionuclides Produced In Spallation Neutron Sources, Phillip W. Patton

Transmutation Sciences Physics (TRP)

A research consortium comprised of representatives from several universities and national laboratories has been established as part of this on-going project to generate internal and external dose conversion coefficients for radionuclides produced in spallation neutron sources. Information obtained from this multi-year study will be used to support the siting and licensing of future accelerator-driven nuclear initiatives within the U.S. Department of Energy complex, including the Spallation Neutron Source (SNS) and Accelerator Production of Tritium (APT) Projects. Determination of these coefficients will also fill data gaps for several hundred radionuclides that exist in Federal Guide Report No. 11 and in Publications …

Design And Evaluation Of Processes For Fuel Fabrication, Georg F. Mauer

Fuels Campaign (TRP)

The objective of this project is the design and evaluation of manufacturing processes for transmuter fuel fabrication. The large-scale deployment of remote fabrication and refabrication processes will be required for all transmutation scenarios. Current program emphasis is on a five-year effort to determine the feasibility of transmutation as a technology to limit the need for repository storage of spent commercial fuel. The evaluation of the fabrication processes will create a decision support data base to document design, operations, and costs. Fabrication processes required for different fuel types differ in terms of equipment types, throughput, and cost. Differential cost Implications of …

Design And Evaluation Of Processes For Fuel Fabrication: Quarterly Progress Report #3, Georg F. Mauer

Fuels Campaign (TRP)

The third quarter of the project covered the following:

• Literature Search: The process of evaluating the pertinent literature continued. Results are summarized.

• Mr. Richard Silva, developed an initial work cell simulation with two robots. Rich will continue to develop detailed 3-D process simulation models as his M.Sc. thesis project. Rich is employed with Bechtel at the Yucca Mountain project.

• The equipment detail and estimates were refined based on the literature survey results for different manufacturing plant design options.

• Concepts and Methods for Vision-Based Hot Cell Supervision and control (Ph.D. Student Jae-Kyu Lee )

Humidity And Temperature Boundaries For Biofilm Formation In Yucca Mountain, Terry Ann Else, Penny S. Amy, James Jay, Amy J. Smiecinski

Publications (YM)

To determine the long-term success of the recommended Yucca Mountain high-level nuclear waste repository, studies of bacterial colonization and biofilm development are needed. Bacteria involved in microbially-influenced corrosion and degradation are known to form biofilms with the potential to impact the integrity of repository packaging and structural materials. Temperature and humidity are environmental factors that can greatly affect biofilm formation. Therefore, it is necessary to determine the temperature and humidity conditions that affect biofilm formation. Microcosms, which simulated the repository environment of Yucca Mountain, were placed at temperatures ranging from 30° C to 70° C and in relative humidities ranging …

Photoexcitation Of A Dipole-Forbidden Resonance In Helium, B. Krassig, E. P. Kanter, S. H. Southworth, Renaud Guillemin, Oliver Hemmers, Dennis W. Lindle, R. Wehlitz, N. L. S. Martin

Environmental Studies Faculty Publications

We have observed photoexcitation of the dipole-forbidden 1s²¹S₀→2p²¹D₂ resonance in helium by measuring the nondipolar forward-backward asymmetry of photoelectron angular distributions in the 2ℓ2ℓ^′ autoionizing region. By exploiting the electric dipole-quadrupole interference in the excitation of both the 2s2p¹P₁ and 2p²¹D₂ levels, we have observed the quadrupole resonance in photoabsorption and extracted its Fano line shape parameters and the relative phase of the 1sEp and 1sEd continua. We find the quadrupole line profile index q₂ to be markedly different from theoretical expectations.

The Fission Properties Of Curium Separated From Spent Nuclear Fuel, William Culbreth, Elizabeth Bakker, Jason Viggato

Separations Campaign (TRP)

Curium poses special problems in the chemical preparation of spent nuclear fuel for transmutation. Once separated from the other minor actinides, the seven curium isotopes in spent fuel can lead to nuclear fission with the subsequent release of a large amount of radiation. Several isotopes of curium also generate a significant amount of heat by radioactive decay. Sustained fission can be avoided by preventing the accumulation by more that a critical mass of curium. The heat generation of curium presents even more restriction on the mass of curium that can safely be contained in one location.

To analyze the nuclear …

Radiation Transport Modeling Of Beam-Target Experiments For The Aaa Project: Quaterly Report, William Culbreth

Reactor Campaign (TRP)

The national development of technology to transmute nuclear waste depends upon the generation of high energy neutrons produced by proton spallation. Proton accelerators, such as LANSCE at the Los Alamos National Laboratory, are capable of producing 800 MeV protons. By bombarding a lead/bismuth target, each proton may generate 500 or more neutrons that can activate fission products or induce the fission of transuranic isotopes.

The Monte Carlo radiation transport code MCNPX developed at LANL is an important tool in the design of transmuter technology. It must be validated, however, for the neutron energy that will be employed. Experiments are being …

Nuclear Criticality Analyses Of Separations Processes For The Transmutation Fuel Cycle: Quarterly Report, William Culbreth, Pang Tao

Separations Campaign (TRP)

During the first two quarters of the work, the tasks included training students in the use of Monte Carlo codes used in radiation transport studies and the assessment of neutron multiplication factors for specific problems outlined by ANL-East through Drs. Laidler and Vandegrift.

The proposal also included objectives for the first year of work on this project, as listed below. The work conducted in the second quarter of the project was in partial completion of these objectives.

• Train UNLV students in the use of SCALE and/or MCNP for the assessment of nuclear criticality.

• Assess neutron multiplication factor, k …

Design And Analysis Of A Process For Melt Casting Metallic Fuel Pins Incorporating Volatile Actinides, Yitung Chen, Darrell Pepper, Randy Clarksean

Fuels Campaign (TRP)

UNLV has developed and will continue to develop process models for the analysis of melt casting processes. This work will continue to be performed under the guidance of Argonne National Laboratory (ANL) engineers to ensure that their knowledge and experience benefits the project. The research to be conducted during the second year will center on performing detailed analyses on a conceptual design of an inductively heated skull-crucible casting furnace. Processing conditions will be analyzed, basic models utilized, and detailed heat and mass transfer models will be developed to analyze the most promising processes. The goal of this second year is …

University Of Nevada, Las Vegas Advanced Accelerator Applications University Participation Program: Quarterly Report Fourth Quarter (December 2001 To February 2002), Anthony Hechanova

Transmutation Research Program Reports (TRP)

This Quarterly Report is a primary deliverable from the University of Nevada, Las Vegas (UNLV) Advanced Accelerator Applications (AAA) University Participation Program (UPP) Director to the U.S. Department of Energy (DOE) as described in the UNLV AAA proposal and Statement of Work for the Fourth Quarter.

The UNLV AAA UPP Director implements the program’s administration using staff from the Harry Reid Center for Environmental Studies (HRC) to ensure that work conducted under the UNLV AAA UPP meets program objectives. The UNLV AAA program consists of three components: Program Support, Research Infrastructure Augmentation, and Student Research.

Third Quarter Report, Covering January Through March 2002, John Farley

Transmutation Sciences Materials (TRP)

Progress from June 2001-November 2001 was presented at the winter meeting of the American Nuclear Society in Reno (November 12-15, 2001), and incorporated into a refereed conference proceeding. A copy of the refereed conference proceeding has been provided to Tony Hechanova. In brief, the paper described the new program to examine the corrosive effects of lead-bismuth eutectic (LBE) on steels. We employed various types of surface studies (Scanning Electron Microscope [SEM], and X-ray Photoelectron Spectrometry [XPS]) to examine steel samples that had been exposed to LBE for various lengths of time at various temperatures. The goal is to understand the …

Design And Evaluation Of Processes For Fuel Fabrication: Quarterly Progress Report #2, Georg F. Mauer

Fuels Campaign (TRP)

The second quarter of the project covered the following:

• Project review with Dr. Mitchell Meyer, ANL West: A project review of the transmuter fuels project was conducted during the January 2002 AAA meeting in Las Vegas.

• A second graduate student, Mr. Richard Silva, began working on the project. Rich will develop detailed 3-D process simulation models as his M.Sc. thesis project. Rich is employed with Bechtel at the Yucca Mountain project.

• AAA Seminar Presentation by Mr. Jae-Kyu Lee and G. Mauer. Title: Transmuter Fuel Fabrication Processes.

• More equipment detail and estimates were developed for different manufacturing …

Design And Analysis For Melt Casting Metallic Fuel Pins Incorporating Volatile Actinides: Quarterly Progress Report 11/16/01- 2/15/02, Yitung Chen, Randy Clarksean, Darrell Pepper

Fuels Campaign (TRP)

An important aspect of the Advanced Accelerator Applications (AAA) program is the development of a casting process by which volatile actinide element (i.e., americium) can be incorporated into metallic alloy fuel pins. The traditional metal fuel casting process uses an inductively heated crucible.

This process works well for the fabrication of metal fuel pins traditionally composed of alloys of uranium and plutonium, but does not work well when highly volatile actinides are included in the melt. The problem occurs both during the extended time period required to superheat the alloy melt as well as when the chamber must be evacuated. …

Project Continuation Proposal: Radiation Transport Modeling Of Beam-Target Experiments For The Aaa Project, William Culbreth

Reactor Campaign (TRP)

The AAA program will rely on the use of an accelerator-based transmuter1 to expose spent nuclear fuel to high-energy neutrons. The neutron flux will be sufficient to activate or fission the long-lived isotopes of Tc, I, Pu, Am, Cm, and Np that present a significant radiological hazard in commercial spent fuel. Transmuter fuel will be subcritical and a high-energy proton accelerator is needed to maintain the necessary neutron flux through the use of a neutron spallation target. The maximum neutron energy produced by spallation (~ 800 MeV) is significantly higher than that produced by a commercial light water reactor (~ …

Radiation Transport Modeling Of Beam-Target Experiments, William Culbreth, Denis Beller

Reactor Campaign (TRP)

In the first year of the UNLV effort, researchers planned to develop the models of the experimental systems to predict the neutron flux and leakage from the experimental targets using the MCNPX code suite in order to help determine these missing parameters. To support these models, the researchers project, or estimate, values for the unknown parameters describing various events and phenomena occurring within the beam-target experiment. The results of these simulations will then be compared against the observed neutron leakage rates and energies. The estimates for the unknown parameters are then revised to correlate with the observed values (these parameters …

University Of Nevada, Las Vegas Transmutation Research Program Annual Report 2001, Anthony Hechanova, Elizabeth Johnson, Gary Cerefice

Transmutation Research Program Reports (TRP)

The UNLV Transmutation Research Program was established in March 2001 as part of the national Advanced Accelerator Applications program to develop the technologies necessary for the ecological and economical treatment of spent nuclear fuel.

The primary role of the UNLV program in the national effort is the training of graduate and undergraduate students in nuclear engineering and other related fields to support the augmentation of the U.S. human infrastructure for transmutation technologies.

To accomplish this role, UNLV has developed the TRP with the primary focus of supporting student research into transmutation and supporting technologies. This focus is realized through the …

Corrosion Of Steel By Lead Bismuth Eutectic, John Farley, Dale L. Perry, Allen L. Johnson

Transmutation Sciences Materials (TRP)

This research program will analyze various steel samples that have been exposed to LBE as part of the national program to develop LBE and transmutation technologies. This information will be paramount in developing engineering efforts to control, avoid, and/or minimize the effect of corrosion of steels by LBE in transmuter and LBE systems. Additionally, this program provides UNLV researchers with hands-on experience that will be crucial in developing the UNLV LBE program, supporting the University’s mission with the ISTC target complex, and the future development of additional facilities to examine LBE systems.

The research group plans to test the hypothesis …

Corrosion Of Steel By Lead Bismuth Eutectic: Year 1 Annual Report, John Farley

Transmutation Sciences Materials (TRP)

The goal is to investigate the corrosion of stainless steel by lead-bismuth eutectic (LBE), which has been proposed for use as a blanket coolant and a spallation target in the transmuter.

Neutron Multiplicity Measurements Of Target/Blanket Materials, Carter D. Hull, William H. Johnson

Transmutation Sciences Physics (TRP)

To begin developing the database necessary for the validation and benchmarking of the LAHET component of the MCNPX code suite, the UNLV research program has set forth the following objectives. First, the current MCNPX suite will be used to develop models of multi-element neutron detector systems. These models of the detector systems will be incorporated into the design of detailed models for the entire detector-target system. These models will first be used to help design the irradiation experiments, and then will be used to model the behavior of the system. Irradiation experiments corresponding to the detector-target system models will be …

Development Of Dose Conversion Coefficients For Radionuclides Produced In Spallation Neutron Sources, Phillip W. Patton, Mark Rudin

Transmutation Sciences Physics (TRP)

For the first year of this effort, the UNLV research team set out four objectives. First, the university and laboratory consortium had to be established. This consortium was tasked with helping to determine the methodology for determining the dose coefficients, and to ensure that the resulting DCs will be of use to the national programs developing accelerator-driven nuclear systems (such as the SNS or an accelerator-driven transmutation system) and to the health physics community as a whole. The second goal of this program was to determine a methodology and then prioritize the radionuclides so that the research effort would address …

Development Of Dose Coefficients For Radionulides Produced In Spallation Neutron Sources: Annual Report, Phillip W. Patton, Mark Rudin

Transmutation Sciences Physics (TRP)

The University of Nevada, Las Vegas (UNLV) Transmutation Research Program has been tasked to support U.S. Department of Energy (DOE) efforts to assess the health risks associated with the operation of each of their accelerator-driven nuclear facilities for both NEPA and PSAR development. Quantifying the radiological risks to workers will have to be addressed during the design and siting of each of these facilities. U.S. Environmental Protection Agency (EPA) Federal Guidance Report No. 11 “Limiting Values of Intake and Air Concentration and Dose Conversion Factors for Inhalation, Submersion, and Ingestion”, developed two derived guides, Annual Limit on Intake (ALI) and …

An Interdatabase Comparison Of Nuclear Decay And Structure Data Utilized In The Calculation Of Dose Coefficients For Radionuclides Produced In A Spallation Neutron Source, John P. Shanahan, K. Eckerman, A. Arndt, C. Gold, Phillip W. Patton, Mark Rudin, R. Brey, T. Gesell, V. Rusetski, S. Pagava

Transmutation Sciences Physics (TRP)

Internal and external dose coefficient values have been calculated for 14 anthropogenic radionuclides which are not currently presented in Federal Guidance Reports Nos. 11, 12, and 13 or Publications 68 and 72 of the International Commission on Radiological Protection. Internal dose coefficient values are reported for inhalation and ingestion of 1 μm and 5 μm AMAD particulates along with the f₁ values and absorption types for the adult worker. Internal dose coefficient values are also reported for inhalation and ingestion of 1 μm AMAD particulates as well as the f₁ values and absorption types for members of the …

Nuclear Criticality, Shielding, And Thermal Analyses Of Separations Processes For The Transmutation Fuel Cycle, William Culbreth, Denis Beller

Separations Campaign (TRP)

The remediation of nuclear waste created by conventional fission reactors will rely upon the separation of the waste products for further treatment. The UREX+ process now under review will involve the use of an aqueous chemical process to separate out depleted uranium resulting in a product containing minor actinides, fission products, cesium, strontium, technetium, and iodine. The radioactive decay of strontium and cesium produces roughly half of the thermal and gamma production in spent fuel and the relatively short halflife of isotopes of both of these elements requires storage for about 300 years before heat and radiation decreases to safe …

Nuclear Criticality Analyses Of Separations Processes For The Transmutation Fuel Cycle, William Culbreth, Pang Tao, Denis Beller

Separations Campaign (TRP)

The separation and partitioning of used commercial reactor fuel is a vital component of any reprocessing or transmutation strategy. To process the high actinide fuels required for a transmutation effort, the Chemical Technology Division (CMT) at Argonne National Laboratory (ANL) is developing a pyrochemical separations process. Currently, this work is being done via small experiments. While this is more than sufficient to develop the technologies required to process actinide-bearing fuels, it does not allow for the direct investigation of criticality concerns that would be present in larger systems. As the volume of waste to be treated increases, a higher probability …

Design And Analysis Of A Process For Melt Casting Metallic Fuel Pins Incorporating Volatile Actinides, Yitung Chen, Darrell Pepper, Randy Clarksean

Fuels Campaign (TRP)

The Transmutation Research Program requires the incorporation of non-fertile actinides into the fuel matrix for the transmuter blanket. One of three currently proposed candidate matrices for the transmuter blanket is a metallic alloy fuel matrix. Metallic fuels are an outstanding candidate for a transmutation fuel due to excellent irradiation performance and ease of fabrication. However, including a volatile constituent during fabrication of these fuel pins presents a challenge. High vapor pressure actinides, particularly americium, are susceptible to rapid vaporization and transport using traditional metal fuel casting processes. As a result, only a fraction of the desired charge is incorporated into …

University Of Nevada, Las Vegas Advanced Accelerator Applications University Participation Program: Quarterly Report, Third Quarter (September To November 2001), Anthony Hechanova

Transmutation Research Program Reports (TRP)

This Quarterly Report is a primary deliverable from the University of Nevada, Las Vegas (UNLV) Advanced Accelerator Applications (AAA) University Participation Program (UPP) Director to the U.S. Department of Energy (DOE) as described in the UNLV AAA proposal and Statement of Work for the Third Quarter.

The UNLV AAA UPP Director implements the program’s administration using staff from the Harry Reid Center for Environmental Studies (HRC) to ensure that work conducted under the UNLV AAA UPP meets program objectives. The UNLV AAA UPP consists of three components: Program Support, Research Infrastructure Augmentation, and Student Research.

Radiation Transport Modeling Of Beam-Target Experiments For The Aaa Project: Quaterly Report, William Culbreth

Reactor Campaign (TRP)

The national development of technology to transmute nuclear waste depends upon the generation of high energy neutrons produced by proton spallation. Proton accelerators, such as LANSCE at the Los Alamos National Laboratory, are capable of producing 800 MeV protons. By bombarding a lead/bismuth target, each proton may generate 500 or more neutrons that can activate fission products or induce the fission of transuranic isotopes.

The Monte Carlo radiation transport code MCNPX developed at LANL is an important tool in the design of transmuter technology. It must be validated, however, for the neutron energy that will be employed. Experiments are being …

Nuclear Criticality Analyses Of Separations Processes For The Transmutation Fuel Cycle: Quaterly Report, William Culbreth, Pang Tao

Separations Campaign (TRP)

During the first quarter of the work, the tasks included training students in the use of Monte Carlo codes used in radiation transport studies and the assessment of neutron multiplication factors for specific problems outlined by ANL-East through Drs. Laidler and Vandegrift.

The proposal also included objectives for the first year of work on this project, as listed below. The work conducted in the first quarter of the project was in partial completion of these objectives.

• Train UNLV students in the use of SCALE and/or MCNP for the assessment of nuclear criticality.

• Assess neutron multiplication factor, k_{eff …}