Physical Sciences and Mathematics Commons^™

Afci Quarterly Input – Unlv July 1 Through September 30, 2005, Harry Reid Center For Environmental Studies. Nuclear Science And Technology Division

Transmutation Research Program Reports (TRP)

Quarterly report highlighting research projects, activities 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.

The Electrochemical Separation Of Curium And Americium: Quaterly Report April - June, 2005, David W. Hatchett, Kenneth Czerwinski

Separations Campaign (TRP)

This research report outlines the current status and progress associated with the electrochemical separation of Curium and Americium.

Results

• We have completed the electrochemical investigation in of the Ce³⁺/Ce⁴⁺ redox couple and have determined the optimum experimental conditions.

• Computer modeling of the cerium using the JChess speciation-modeling program has been completed for the Ce redox couple. Traditional complexing ligands such as EDTA, oxalate, NTA, phosphate, acetate, and sulfate have been purchased and will be used to initiate the complexation and electrochemical characterization.

• Electrochemical investigations have continued on the Eu²⁺/Eu³⁺ redox …

Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix: Neutronic Evaluation Of Zro2-Mgo Inert Fuels, E. Shwageraus, A. Galperin, E. Fridman, S. Kolesnikov

Fuels Campaign (TRP)

This report presents results of the analysis performed within the framework of “Dissolution, Reactor, and Environmental Behavior of ZrO₂-MgO Inert Fuel Matrix” project managed by University of Nevada at Las Vegas, Harry Reid Center for Environmental Studies. The main objective of the study was to explore the basic neutronic feasibility of using MgO-ZrO₂ as inert fuel matrix for Pu recycling in conventional Light Water Reactors (LWR).

Afci Quarterly Input – Unlv April Through June, 2005, Harry Reid Center For Environmental Studies. Nuclear Science And Technology Division

Transmutation Research Program Reports (TRP)

Quarterly report highlighting research projects, activities 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.

Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix: Neutronic Evaluation Of Zro2-Mgo Inert Fuels, E. Fridman, S. Kolesnikov, E. Shwageraus, A. Galperin

Fuels Campaign (TRP)

This report presents the results of the Task 4, defined in working program as: evaluation of reactivity feedback coefficients. Three main parameters of the Fertile-Free Fuel (FFF) lattices were evaluated: Moderator Temperature Coefficient (MTC), Fuel Temperature Coefficient due to Doppler Effect (DC), and soluble Boron reactivity worth (BW).

One of the major design challenges associated with utilization of FFF is deterioration of the temperature coefficients and control materials reactivity worth caused by high thermal cross-section of Pu and consequent hardening of the neutron spectrum. The purpose of the investigation reported in this section is to estimate the potential of addition …

Inside Unlv, Erin O'Donnell, Diane Russell, Carol C. Harter

Inside UNLV

No abstract provided.

Immobilization Of Fission Iodine By Reaction With A Fullerene Containing Carbon Compound And Insoluble Natural Organic Matrix: Quaterly Report January-March 2005, Spencer M. Steinberg

Separations Campaign (TRP)

We have continued experiments on the reaction of iodate with sphagnum peat moss. We have established that iodate added to a suspension of peat moss undergoes reduction and to a significant extent is incorporated in to the peat moss. We have confirmed the incorporation of iodine into the peat matrix using pyrolysis GC/MS. In addition, we have performed a scaled up pyrolysis using the preparative GC system that was described in a previous report. This instrument consisted of a packed column gas chromatograph (SRI 8010) with a TCD detector and injector valve equipped with a thermal desorber. Pyrolysis experiments were …

Evaluation Of Fluorapatite As A Waste-Form Material: First Quarter Report, January 1 - March 31, 2005, Dennis W. Lindle, Oliver Hemmers

Separations Campaign (TRP)

Fluorapatite, fluorinated calcium phosphate, has been identified as a potential matrix for the entombment of the zirconium fluoride fission product waste stream from the proposed FLEX process. If the efficacy of fluorapatite-based waste-storage can be demonstrated, then new and potentially more-efficient options for handling and separating high-level wastes, based on fluoride-salt extraction, will become feasible. This proposal will develop a dual-path research project to develop a process to fabricate a synthetic fluorapatite waste form for the ZrF₄, FP waste stream, characterize the waste form, examine its performance under environmental conditions, and correlate the behavior of the waste form …

Fundamental Chemistry Of U And Pu In The Tbp-Dodecane-Nitric Acid System: Quaterly Report January - March, 2005, Kenneth Czerwinski, Cynthia-May Gong, Amber Wright

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 …

Fundamental Chemistry Of U And Pu In The Tbp-Dodecane-Nitric Acid System: Quarterly Report January - March, 2006, Amber Wright, Frederic Poineau, Kenneth Czerwinski

Separations Campaign (TRP)

The speciation of hexavalent U and tetravalent Pu will be examined in the Tributylphosphate (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 …

Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix: Quarterly Report, January 2005 To March 2005, Earl Wolfram, Thomas Hartmann, Kenneth Czerwinski

Fuels Campaign (TRP)

This project will examine inert matrix fuels containing ZrO₂ and MgO as the inert matrix, with the relative amount of MgO varied from 30% to 70% in ZrO₂. Reactor physics calculations will be used to examine suitable quantities of burnable poisons from the candidate elements Gd, Er, or Hf with reactor grade Pu providing the fissile component, with up to 10% of ²³⁹Pu. Ceramics will be synthesized and characterized based on the reactor physics results. The solubility the fuel ceramics, in reactor conditions, reprocessing conditions, and repository conditions, will be investigated in a manner to provide …

Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix: Neutronic Evaluation Of Zro2-Mgo Inert Fuels, E. Fridman, S. Kolesnikov, E. Shwageraus, A. Galperin

Fuels Campaign (TRP)

This report presents the results of the Task 3, defined in working program as: evaluation of burnable poison designs. Adopting the basic design of a standard PWR and Pu loadings required for 18-month cycle (results of Task 2), this part of the program is aimed to estimate performance of each BP design and BP material to address challenges of Fertile-Free Fuel (FFF) Concept. Finally, an optimal BP design will be developed and an overall feasibility of FFF concept will be determined. Basically, the main challenge encountered in neutronic design for a FFF core is to develop reactivity control system which …

Immobilization Of Fission Iodine By Reaction With A Fullerene Containing Carbon Compound And Insoluble Natural Organic Matrix: Quaterly Report October-December 2004, Spencer M. Steinberg

Separations Campaign (TRP)

We have conducted a large number of experiments to determine the possible reaction of iodate with sphagnum peat moss. These experiments indicate that the natural organic material reacts with iodate resulting in the formation of organically bound iodine and/or iodide in solution.

In the last quarter, we have conducted a number of experiments at various pHs and several temperatures (70oC, 60oC and 40oC). The reaction of iodate with peat follows pseudo first-order kinetics, although the reaction rate does appear to decrease significantly with reaction time. As noted in a previous report organically bound iodine appears to go through a maximum …

Impact Of Alteration Phase Formation And Microbial Activity On The Fate And Transport Of The Actinides And Fission Products: Alteration Phase Analysis, James Cizdziel, Klaus J. Stetzenbach, Thomas Williams, Abe Van Luik

Publications (YM)

The study of the behavior and movement of radionuclides in the environment is significant to many projects of interest to Southern Nevada, especially for the proposed Yucca Mountain Repository, as well as to the nation-wide issues of radiological releases from a variety of scenarios. Understanding and predicting the release, transport, and fate of radionuclides, particularly the actinide elements, in the Mojave/Great Basin geology is an extremely challenging, multi-faceted problem. In support of the national program to deepen our understanding of the behavior of radionuclides in the environment and to better predict the performance of a geological repository at Yucca Mountain, …

Characterization Of Microbial Activity, Mark P. Buttner, Patricia Cruz, Klaus J. Stetzenbach, Abe Van Luik, Thomas Williams, Amy J. Smiecinski

Publications (YM)

The overall goal of this study is to investigate the phenomena that affect the fate and transport of radionuclides in the environment. The objective of this task, “Characterization of Microbial Activity”, is to develop a molecular biological method for the characterization of the microbial population indigenous to the Yucca Mountain Project site, with emphasis in detection and measurement of species or groups of microorganisms that could be involved in actinide and/or metal reduction, and subsurface transport. Subtasks consist of QA planning and preparation, and literature review. This task is part of a cooperative agreement between the UNLV Research Foundation and …

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 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 separations …

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

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 …

Immobilization Of Fission Iodine By Reaction With A Fullerene Containing Carbon Compound And Insoluble Natural Matrix, Spencer M. Steinberg, Gary Cerefice, David W. Emerson

Separations Campaign (TRP)

The recovery of iodine released during the processing of used nuclear fuel poses a significant challenge to the transmutation of nuclear waste. Iodine-129, a long-lived fission product formed by both commercial nuclear power generation and nuclear weapons production, is released when reprocessing nuclear fuel. Since iodine can be concentrated in the human thyroid, any uncontrolled release of iodine may result in an increased rate of thyroid cancer in the exposed population. For this reason, recovery of iodine is important for implementing any nuclear transmutation strategy.

The stability of the association of iodine with FCC and NOM products are studied. Product …

Development, Fabrication And Study Of Fullerene-Containing Carbon Material (Fcc) For Immobilization Of Iodine: Progress Report #1-4, Michael Savopulo, Boris E. Burakov

Separations Campaign (TRP)

During current reporting period the experiments on synthesis of ceramic-like material by conversion of iodine-doped FCC and activated carbon to Si_xC_y have been completed. Cold pressed granules of FCC and activated carbon were rinsed in water-ethanol solution of tetraethoxysilane (TEOS), Si(OC₂H₅)₄, and then used for further synthesis. All new samples obtained have been studied using precise powder XRD analysis.

Development, Fabrication And Study Of Fullerene-Containing Carbon Material (Fcc) For Immobilization Of Iodine: Final Report 2005, Michael Savopulo, Boris E. Burakov

Separations Campaign (TRP)

Immobilization of highly radioactive and long-lived isotope of ¹²⁹I, which is a fission product in spent nuclear fuel, requires development of new durable host-materials.

Iodine is a very volatile chemical element, and even its chemically strong compounds such as AgI and CuI are not stable under ultraviolet irradiation or oxidizing conditions. Therefore, development of host materials for iodine immobilization is based on unusual approach – the search and testing of new compounds which were not studied before in respect of iodine sorption and strong fixation.

Although FCC material demonstrated high loading capacity to iodine sorption it is necessary to …

Evaluation Of Fluorapatite As A Waste-Form Material, Dennis W. Lindle, Oliver Hemmers, Dale L. Perry

Separations Campaign (TRP)

Argonne National Laboratory has proposed a new extraction procedure to handle TRISO-coated fuels, the Fluoride Extraction Process, or FLEX. The FLEX process is designed to separate the uranium in the fuel from the actinides and most fission products by taking advantage of the unique properties of uranium hexafluoride (UF₆). In the FLEX process, the used TRISO fuel is reacted with zirconium fluoride salt, forming UF₆ and the fluoride salts of the actinides and fission products. At process temperatures, the UF₆ volatizes into a gas, and is released from the molten salt mixture. This leaves behind the …

Development Of Fluorapatite As A Waste Form: Final Report #280204-1, Boris E. Burakov

Separations Campaign (TRP)

In the framework of Agreement #280204 (first year) it was necessary to review methods of apatite synthesis; identify optimal procedure of precursor preparation; obtain and study first fluorapatite samples. Although, some apatite-based ceramics were successfully synthesized using co-precipitated precursors and sintering method, there are still a lot of uncertainties related to optimal apatite doping with different radionuclides and non-radioactive elements. It is necessary to provide complete incorporation of waste elements into apatite crystalline structure avoiding formation of separate phases of radionuclides. Also, it is important to note that real waste streams might contain radionuclides with essentially different chemical features such …

Electrochemical Separation Of Curium And Americium, David W. Hatchett, Kenneth Czerwinski

Separations Campaign (TRP)

The objective of this project is to use electrochemical techniques to develop a thermodynamic understanding of actinide and lanthanide species in aqueous solution and use this data to effectively separate species with very similar chemical properties. In consultation with our DOE collaborator, electrochemical methods and materials will be evaluated and used to exploit the thermodynamic differences between similar chemical species enhancing our ability to selectively target and sequester individual species from mixtures.

The following were specific goals for this year:

• To develop a fundamental understanding of the thermodynamic properties of actinide and lanthanide species such as Cm, Am, Ce, Nd, …

Fundamental Chemistry Of U And Pu In The Tbp-Dodecane-Nitric Acid System: Quarterly Report, Kenneth Czerwinski, Cynthia-May Gong, Amber Wright

Separations Campaign (TRP)

The speciation of hexavalent U and tetravalent Pu will be examined in the TBPdodecane- 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 …

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

Separations Campaign (TRP)

The research objectives of this project are as follows:

• To determine the influence of nitrate on the speciation of U and Pu in the TBP-dodecane-nitric acid system. The aqueous and organic speciation of U and Pu are examined as a function of the nitric acid concentration, nitrate concentration (by the addition of NaNO₃), actinide ion concentration, temperature, and time.
• To determine the speciation of U and Pu with AHA in the presence and absence of TBP-dodecane organic phase. The aqueous and organic speciation of U and Pu are evaluated as a function of AHA concentration, metal ion concentration, …

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.

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 on LBE systems has come from the Russians, who have over 80 reactor-years experience with LBE coolant in their Alpha-class submarine reactors. The Russians found …

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

Transmutation Sciences Materials (TRP)

The primary objective of this task was to evaluate the effects of environmental and mechanical parameters on environment induced degradations of candidate target structural materials for applications in spallation-neutron-target systems. The materials selected for evaluation and characterization were martensitic stainless steels including Alloys HT-9, EP-823, and 422.

Accelerator-driven transmutation systems involve bombarding a target material such as molten lead-bismuth-eutectic (LBE) by a proton beam, thereby producing neutrons. The molten LBE target will be contained in a subsystem structural container made of a suitable material such as Alloys HT-9, EP-823, and 422. During the transmutation process, the target structural material may …

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The corrosion of structural materials is a major concern for the use of lead-bismuth eutectic (LBE) systems for nuclear applications such as in transmuter targets or fast reactors. Corrosion in liquid metal systems can occur through various processes, including, for example, dissolution, formation of inter-metallic compounds at the interface, and penetration of liquid metal along grain boundaries. Predicting the rate of these processes depends on numerous system operational factors: temperature, system geometry, thermal gradients, solid and liquid compositions, and velocity of the liquid metal, to name a few. Corrosion, along with mechanical and/or hydraulic factors, often contributes to component failure. …

Interaction Between Metal Fission Products And Triso Coating Materials: A Study Of Chemical Bonding And Interdiffusion: 1st Quarter Report, 2005, Clemens Heske

Fuels Campaign (TRP)

In this project we utilize a combination of state-of-the-art soft X-ray spectroscopies to understand the chemical bonding between metal fission products (Pd and Ag) with coating layers in TRISO fuel particles (SiC and pyrocarbon). We are primarily focusing on an analysis of intermediate chemical phases at the interface, the intermixing/diffusion behavior, and the electronic interface structure as a function of material choice (metal and coating materials), temperature, and external stress. In the current first project year, we are beginning these investigations with the Pd/SiC interface, as discussed in the previous two quarterly reports. Our first experiments (both using our lab …

Interaction Between Metal Fission Products And Triso Coating Materials: A Study Of Chemical Bonding And Interdiffusion: 2nd Quarter Report, 2005, Clemens Heske

Fuels Campaign (TRP)

The goal of our project is to investigate interface corrosion processes in TRISO nuclear fuel particles. For this purpose, we are undertaking a detailed study of the interface formation between potential candidates for metallic fission products (Pd, Ag, and Cs), likely to diffuse from the kernel of the TRISO particles, with the TRISO coating layers. As a starting point, we are investigating the Pd/SiC interface and will extend our studies to Ag/SiC during our current summer research campaign. The experimental approach comprises the preparation of metal/SiC interfaces in-situ in our ultra-high vacuum system by electron-beam deposition. In order to understand …