Nuclear Engineering Commons^™

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

Fuels Campaign (TRP)

After considering the heating mechanisms, casting issues, crucible design and issues related to the mass transport of americium, an ISM system was selected for melting the feedstock and casting fuel pins containing high vapor pressure actinides (americium). The finite element commercial software (FIDAP) was used to simulate the induction melting process and the casting process. Phase change is considered both in the heating and in the solidification process. Various factors and properties are studied, such as boundary conditions and initial conditions, output current, frequency of the current, main dimensions of the system, mold preheating temperature, heat transfer coefficient and mold …

High Temperature Heat Exchanger Project: Quarterly Progress Report April 1, 2004 Through June 30, 2004, Anthony Hechanova

Publications (NSTD)

UNLV hosted a meeting on NHI Materials and Heat Exchanger Design on Monday, May 17. Paul Pickard (Sandia National Lab) and Bill Corwin (Oak Ridge National Lab) facilitated the meeting. The purpose of the meeting was to summarize the hydrogen materials and heat exchanger requirements and priorities for UNLV staff and their collaborators to support the research proposal solicitation for the UNLV Research Foundation HTHX program. Attendance was heavier than anticipated and required a change of venue to accommodate the crowd of over 30.

Afci Quarterly Input – Unlv April Through June, 2004, Harry Reid Center For Environmental Studies. Nuclear Science And Technology Division

Transmutation Research Program Reports (TRP)

Quarterly report highlighting research projects and objectives of the Transmutation Research Program at the Nuclear Science & Technology Division, Harry Reid Research Center.

The University of Nevada, Las Vegas supports the AFCI through research and development of technologies for economic and environmentally sound refinement of spent nuclear fuel. The UNLV program has four components: infrastructure, international collaboration, student-based research, and management and program support.

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics-Task V: Third Quarterly Report 03/01/2004-05/31/2004, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The Lead-Bismuth eutectic (LBE) has been determined from previous experimental studies by the Russians and the European scientific community to be a potential material that can be used as a spallation target and coolant for the TRP proposed application. Properly controlling the oxygen content in LBE can drastically reduce the LBE corrosion to structural steels. However, existing knowledge of material corrosion performance was obtained from point-wise testing with only very sparse experimental data. Scientists have noticed that the concentration of oxygen dissolved in the liquid alloy could control the corrosion rate of steels exposed to Pb or Pb-Bi. At high …

Design And Evaluation Of Processes For Fuel Fabrication: Quarterly Progress Report #11, Georg F. Mauer

Fuels Campaign (TRP)

The eleventh quarter of the project covered the following:

• Mr. Richard Silva successfully defended his thesis in April 2004 and graduated from the MEG Master’s program.

• Further refinements on Concepts and Methods for Vision-Based Hot Cell Supervision and control, focusing on rule-based object recognition (Ph.D. Graduate Jae-Kyu Lee). Ms. Caroline Wiejak, an exchange student from the ESIEE in Marne-la-Vallee, France is continuing with the image analysis effort. To date, she has transferred Jae-Kyu’s code to Matlab, and is presently expanding its application to more complex 3D shapes.

• Graduate student Jamil Renno refined and detailed his simulations of …

Fundamental Chemistry Of U And Pu In The Tbp-Dodecane-Nitric Acid System, Kenneth Czerwinski, Byron Bennett

Separations Campaign (TRP)

The speciation of hexavalent U and tetravalent Pu will be examined in the TBP-dodecane-nitric acid systems. This topic is chosen based on data needs for separation modeling identified by the AFCI. Emphasis will be placed on studying the influence of nitrate and acetohydroxamic acid on U and Pu speciation as well as conditions where a third phase forms in the organic phase. The organic phase will be 30% TBP in dodecane. Equal volumes of aqueous and organic phase will be used. The speciation of the actinides in the aqueous and organic phase will be determined by a number of different …

Development Of Nanostructure Based Corrosion-Barrier Coatings On Steel For Transmutation Applications, Biswajit Das

Transmutation Sciences Materials (TRP)

The objective of this project is to develop a novel nanostructure based coating technology that will provide significantly improved corrosion resistance for steel in LBE at elevated temperatures (500 - 600^oC), as well as provide long-term reliability under thermal cycling. The nanostructure based coatings will consist of a layer of nanoporous alumina with the pores filled with an oxidizing metal such as Cr, followed by a capping layer of alumina. Alumina, which is a robust anti-corrosion material, provides corrosion resistance at elevated temperatures. The Cr serves two purposes: (1) it acts as a solid filler material for the …

Design Concepts And Process Analysis For Transmuter Fuel Manufacturing, Georg F. Mauer

Fuels Campaign (TRP)

This proposal addresses the subject heading ‘Transmutation Fuel Development’ in the 2004 research topic list of the UNLV Transmutation Research Program (TRP) and DOE Advanced Fuel Cycle Initiative (AFCI). The large-scale deployment of remote fabrication and refabrication processes (with a capacity of approx. 100 metric tons of Minor Actinides (MA) annually) will be required for all transmutation scenarios. The objective of this project is the design, analysis, and evaluation of manufacturing processes for transmuter fuel fabrication. Fabrication processes for different fuel types differ in terms of equipment types, throughput, and cost. The evaluation of the fabrication processes will create a …

Effect Of Silicon Content On The Corrosion Resistance And Radiation-Induced Embrittlement Of Materials For Advanced Heavy Liquid Metal Nuclear Systems, Ajit K. Roy

Transmutation Sciences Materials (TRP)

The purpose of this collaborative research project involving the University of Nevada Las Vegas (UNLV), Los Alamos National Laboratory (LANL) and Idaho State University (ISU) is to evaluate the effect of silicon (Si) content on the corrosion behavior and radiation-induced embrittlement of martensitic stainless steels having chemical compositions similar to that of the modified 9Cr-1Mo 2 steel. Recent studies at LANL involving Alloy EP-823 of different Si content have demonstrated that increased Si content in this alloy may enhance the corrosion resistance in molten lead-bismuth-eutectic (LBE). Since very little data exists in the open literature on the beneficial effect of …

Modeling, Optimization, And Flow Visualization Of Chemical Etching Process In Niobium Cavities, Sathish K. Subramanian

UNLV Theses, Dissertations, Professional Papers, and Capstones

Niobium cavities are important component of the linear accelerators. Researchers have concluded that buffered chemical polishing on the inner surface of the cavity improves its performance. However the mechanism of chemical polishing is not well understood. A finite element computational fluid dynamics (CFD) model was developed to simulate the fluid flow characteristics of chemical etching process inside the cavity. The CFD model is then used to optimize the baffle design. The analysis confirmed the observation of other researchers that the iris section of the cavity received more etching than the equator regions. The baffle, which directs flow towards the walls …

Development Of Integrated Process Simulation System Model For Spent Fuel Treatment Facility (Sftf) Design, Yitung Chen, Sean Hsieh

Separations Campaign (TRP)

The Advanced Fuel Cycle Initiative (AFCI) and Transmutation Research Program-University Participation Program (TRP-UPP) supported by Department of Energy of the United States have been developing many important technologies for the transmutation of nuclear waste to address long-term disposal issues. While successfully embedding AMUSE module into a dedicated System Engineering Model (TRPSEMPro), developed by the Nevada Center for Advanced Computational Methods (NCACM) at the University of Nevada-Las Vegas collaborating with Argonne National Laboratory (ANL), ANL is interested in further simulating the Light Water Reactor (LWR) Spent Fuel Treatment Facility (SFTF) combining commercial process simulation and analysis packages and core calculation of …

Theoretical Modeling Of Protective Oxide Layer Growth In Non-Isothermal Lead-Alloys Coolant Systems, Yitung Chen, Jinsuo Zhang, Jichun Li

Transmutation Sciences Materials (TRP)

The goal of the proposed research project is to provide basic understanding of the protective oxide layer behaviors and to develop oxide layer growth models of steels in non-isothermal leadalloys (lead or lead-bismuth eutectic) coolant systems. It is widely recognized that the corrosiveness of the lead-alloys is a critical obstacle and challenge for which it can be safely used or applied in the nuclear coolant systems. Active oxygen control technique can promote the formation of the “self-healing” oxide films on the structural material surface, drastically reducing steel corrosion and coolant contamination. Many experiments of steels exposed to flowing leadalloys have …

Use Of Positron Annihilation Spectroscopy For Stress-Strain Measurements, Ajit K. Roy

Transmutation Sciences Materials (TRP)

The purpose of this collaborative research project involving the University of Nevada Las Vegas (UNLV) and Idaho State University (ISU) is to evaluate the feasibility of determining residual stresses of welded, bent (three-point-bend), and cold-worked engineering materials using a new nondestructive technique based on positron annihilation spectroscopy (PAS). The proposed technique is to use γ-rays from a small MeV electron linear accelerator (Linac) to generate positrons inside the test sample via 2 pair production. This method can be used for materials characterization and investigation of defects in thick samples that usually cannot be accomplished by conventional positron technique or other …

High Temperature Heat Exchanger Project: Quarterly Progress Report January 1, 2004 Through March 31, 2004, University Of Nevada, Las Vegas. Research Foundation, Robert F. D. Perret

Publications (NSTD)

Mutually satisfactory language has been developed to permit signing of a subcontract between the General Atomics Corporation and the UNLV Research Foundation. The contract is signed.

Modeling, Fabrication, And Optimization Of Niobium Cavities: Phase Iii Third Quarterly Report, Robert A. Schill Jr., Mohamed Trabia

Transmutation Sciences Materials (TRP)

Niobium cavities are important parts of the integrated NC/SC high-power linacs. Over the years, researchers in several countries have tested various cavity shapes. They concluded that elliptically shaped cells are the most appropriate shape for superconducting cavities. The need for very clean surfaces lead to the use of a buffered chemical polishing produce for surface cleaning to get good performance of the cavities. The third phase concludes the experimental a fluid flow study and optimization study. The first quarter and second quarter of phase three also begins the experimental set-up of secondary emission studies from niobium in superconducting mode. This …

Preparation Studies For Secondary Electron Emission Experiments On Superconducting Niobium, Anoop George, Robert A. Schill Jr.

Transmutation Sciences Materials (TRP)

Accelerator driven transmutation of waste is one complementary approach to deal with spent nuclear fuel as compared to permanent storage. High-energy protons generated by a particle accelerator collide with a heavy metal target producing neutrons. Long-lived radioactive isotopes interacting with the neutrons transmute into shorter-lived isotopes. To generate the high-energy protons efficiently, linear accelerators use multi-cell superconducting radio frequency (RF) cavities made of niobium. Superconducting niobium cavities have several advantages, including small power dissipation. The high electromagnetic fields present in these cavities may result in undesired field emission from surface imperfections with the probability of generating an avalanche of secondary …

Afci Quarterly Input – Unlv January Through March, 2004, Harry Reid Center For Environmental Studies. Nuclear Science And Technology Division

Transmutation Research Program Reports (TRP)

Quarterly report highlighting research projects and objectives of the Transmutation Research Program at the Nuclear Science & Technology Division, Harry Reid Research Center.

The University of Nevada, Las Vegas supports the AFCI through research and development of technologies for economic and environmentally sound refinement of spent nuclear fuel. The UNLV program has four components: infrastructure, international collaboration, student-based research, and management and program support.

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics-Task V: First Quarterly Report 01/12/04-02/29/04, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The Lead-Bismuth eutectic (LBE) has been determined from previous experimental studies by the Russians and the European scientific community to be a potential material that can be used as a spallation target and coolant for the TRP proposed application. Properly controlling the oxygen content in LBE can drastically reduce the LBE corrosion to structural steels. However, existing knowledge of material corrosion performance was obtained from point-wise testing with only very sparse experimental data. Scientists have noticed that the concentration of oxygen dissolved in the liquid alloy could control the corrosion rate of steels exposed to Pb or Pb-Bi. At high …

Design And Evaluation Of Processes For Fuel Fabrication: Quarterly Progress Report #10, Georg F. Mauer

Fuels Campaign (TRP)

The tenth quarter of the project covered the following:

• Mr. Richard Silva continued the development of a simulation model with a Waelischmiller hot cell robot, and is close to completing his M.Sc. thesis project. Rich will likely defend his thesis in April 2004.

• A project review meeting with Dr. Mitch Meyer and other ANL scientists was held in December 2003 at ANL West, Idaho Falls, ID. Dr. Meyer described ANL long term research objectives with regard to transmuter fuel manufacturing.

• Further refinements on Concepts and Methods for Vision-Based Hot Cell Supervision and control, focusing on rule-based object …

Design And Evaluation Of Processes For Fuel Fabrication: Quarterly Progress Report #10, Georg F. Mauer

Fuels Campaign (TRP)

The tenth quarter of the project covered the following:

• Mr. Richard Silva continued the development of a simulation model with a Waelischmiller hot cell robot, and is close to completing his M.Sc. thesis project. Rich will likely defend his thesis in April 2004.

• A project review meeting with Dr. Mitch Meyer and other ANL scientists was held in December 2003 at ANL West, Idaho Falls, ID. Dr. Meyer described ANL long term research objectives with regard to transmuter fuel manufacturing.

• Further refinements on Concepts and Methods for Vision-Based Hot Cell Supervision and control, focusing on rule-based object …

Yucca Mountain Climate Technical Support Representative, Saxon E. Sharpe, Dick Reinhardt, Eric Smistad, Don Baepler, Amy J. Smiecinski

Publications (YM)

The principal investigator (PI), Saxon Sharpe, for Task ORD-FY04-012, DOE Cooperative Agreement DE-FC28-04RW12232, will serve as Yucca Mountain Climate Technical Support Representative for the Department of Energy (DOE) in a series of activities related to past, present, and future climate for the Yucca Mountain Project (YMP) climate program.

As stated in the Viability Assessment of a Repository at Yucca Mountain: “Climate and its changes over time directly affect system performance at Yucca Mountain.” Currently, information from climate studies is used in models that support the Total System Performance Assessment and Licensing Application. It is a model component of all key …

Proposal For No-Cost Extension And Re-Scope For Unlv Trp Project: Neutron Multiplicity Measurements For The Afci Program (Advanced Fuel Cycle Initiative), Denis Beller

Transmutation Sciences Physics (TRP)

The U.S. Advanced Fuel Cycle Initiative (AFCI) is a program to develop economic and environmental methods to reduce the impact of waste from commercial nuclear fuel cycles. One concept for near-complete destruction of waste isotopes from used nuclear fuel is accelerator-driven transmutation. High-power accelerators would be used to produce high-energy charged particles, which then collide with heavy metal targets to create a cascade of neutrons. These neutrons then cause a nuclear chain reaction in subcritical systems. Fission neutrons then transmute fissile waste isotopes as well as other problematic isotopes such as technetium-99 and iodine-129. To design these systems, complex reactor …

High Temperature Heat Exchanger Project (Hthx) Project Quarterly Report, University Of Nevada, Las Vegas. Research Foundation

Publications (NSTD)

On October 24, 2003, the University of Nevada, Las Vegas (UNLV) hosted an all-day HTHX Kickoff Meeting attended by all participating institutional representatives and researchers. Objectives of this meeting were to identify near-term research objectives, coordinate collaborative activities, and identify required urgent action items.

Modeling, Fabrication, And Optimization Of Niobium Cavities: Phase Iii Second Quarterly Report, Robert A. Schill Jr., Mohamed Trabia

Transmutation Sciences Materials (TRP)

Niobium cavities are important parts of the integrated NC/SC high-power linacs. Over the years, researchers in several countries have tested various cavity shapes. They concluded that elliptically shaped cells are the most appropriate shape for superconducting cavities. The need for very clean surfaces lead to the use of a buffered chemical polishing produce for surface cleaning to get good performance of the cavities. The third phase concludes the experimental a fluid flow study and optimization study. The first quarter and second quarter of phase three also begins the experimental set-up of secondary emission studies from niobium in superconducting mode. This …

Development Of A Systems Engineering Model Of The Chemical Separations Process, Yitung Chen, Darrell Pepper, Sean Hsieh

Separations Campaign (TRP)

The chemical processing of used nuclear fuel is an integral component of any strategy for the transmutation of nuclear waste. Due to the large volume of material that must be handled in this first step of the transmutation process, the efficiency of the separations process is a key factor in the potential economic viability of the transmutation strategies. The ability to optimize the chemical separation systems is vital to ensure the feasibility of the transmutation program.

Systems analysis, or total systems modeling, is one of the strongest tools available to researchers for understanding and optimizing complex systems such as chemical …

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

Separations Campaign (TRP)

The first step in any transmutation strategy is the separation of radionuclides in used nuclear fuel. The current separation strategy supporting the Advanced Fuel Cycle Initiative (AFCI) program is based on the use of a solvent extraction separation process to separate the actinides, fission products, and uranium from used commercial nuclear fuel, and on the use of pyrochemical separation technologies to process used transmuter fuels. To separate the fission products and transuranic elements from the uranium in used fuel, the national program is developing a new solvent extraction process, the Uranium Extraction Plus, or UREX+, process based on the traditional …

Neutron Multiplicity Measurements Of Target/Blanket Materials, Denis Beller

Transmutation Sciences Physics (TRP)

To optimize the performance of accelerator-driven transmutation subcritical systems (ADS), engineers will need to design the system to operate with a neutron multiplication factor just below that of a critical, or self-sustaining, system. This design criterion requires particle transport codes that instill the highest level of confidence with minimal uncertainty, because larger uncertainties in the codes require larger safety margins in the design and result in a lower efficiency of the ADS transmuter. For current design efforts in the U.S., a Monte Carlo particle transport code MCNPX is used to model neutron production and transport for spallation neutron systems.

While …

Modeling, Fabrication, And Optimization Of Niobium Cavities, Robert A. Schill Jr., Mohamed Trabia, William Culbreth

Transmutation Sciences Materials (TRP)

One of the key technologies for the deployment of acceleratordriven transmutation systems is the accelerator itself. Elliptical superconducting niobium cavities are used to increase the efficiency of the high-power accelerators needed to support the transmutation mission.

One of the major sources of energy loss from a superconducting accelerator cavity is a process known as multiple impacting (or “multipacting”) of electrons. This phenomenon limits the maximum amount of energy and power that the niobium cavity can store. As a result, the maximum power available for accelerating the desired charge, as well as the overall performance of the accelerator is reduced. Furthermore, …

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

Transmutation Sciences Materials (TRP)

There is an active international interest in lead-bismuth eutectic and similar liquid lead systems because of the relevance to the transmutation of nuclear waste, fast reactors, and spallation neutron sources. A successful program in nuclear waste processing that includes transmutation in accelerator-driven systems and fast reactors, would significantly decrease the space requirements for geological repositories.

Materials in these systems must be able to tolerate high neutron fluxes, high temperatures, and chemical corrosion. For lead bismuth eutectic (LBE) systems, there is an additional challenge because the corrosive behaviors of materials in LBE are not well understood. Most of the available information …

Environment-Induced Degradation And Crack-Growth Studies Of Candidate Target Materials, Ajit K. Roy

Transmutation Sciences Materials (TRP)

The primary objective of this task is to evaluate the effect of environmental and mechanical parameters on environment induced degradations of candidate target structural materials for applications in spallation-neutron-target systems, such as accelerator-driven systems for the transmutation of waste. The materials selected for evaluation and characterization are martensitic stainless steels including Alloys HT-9, EP-823 and Type 422 stainless steel (SS).

More recently, this experimental program has been expanded to evaluate the effect of molten lead-bismuth eutectic (LBE) on the corrosion behavior of target structural materials in the presence of oxygen. Since the Materials Performance Laboratory (MPL) at UNLV currently cannot …