Nuclear Engineering Commons^™

Combined Radiation Detection Methods For Assay Of Higher Actinides In Separation Processes (Afci), Denis Beller, Warnick Kernan

Safeguards Campaign (TRP)

The ultimate objective of this project is to develop technology to detect and accurately measure quantities of higher actinides in processing systems without taking frequent samples. These systems include used fuel receipt, separations batches, and pipelines. A variety of measurements may be combined to calculate flow rates of actinide elements with a to-be-determined precision. Nuclear and decay characteristics of materials during processing will be acquired, conceptual designs of monitoring systems will be developed, radiation transport studies will be conducted to develop an understanding of operational regimes, and experiments will be performed to confirm performance. Radiation transport and scoping studies will …

Developing A Sensing System For The Measurement Of Oxygen Concentration In Liquid Pb-Bi Eutectic, Yingtao Jiang, Bingmei Fu

Transmutation Sciences Materials (TRP)

The research objectives of this project were as follows:

• To generate calibration curves of voltage versus oxygen concentration for the YSZ oxygen sensor system under various temperatures in liquid LBE.
• To determine the sensor characteristics of the YSZ sensor system.
• To determine oxygen dissolving rates in LBE under different temperatures in vitro.
• To study the effects of unwanted electrical conductivity, contributed by the mobility of the electrons at high temperatures, for more accurate oxygen measurement.
• To study alternative and promising oxygen measuring methods.

Corrosion Mechanisms And Kinetics Of Steels In Lead-Bismuth Eutectic: Quaterly Report, Allen L. Johnson, John Farley

Transmutation Sciences Materials (TRP)

A large number of studies of corroded samples were conducted using SEM, XPS, probe, and the TEM. Samples from the DELTA loop at LANL and from other sources were examined. Also, the investigation of 316 class stainless steel in LBE is continuing.

Corroded samples of D-9 steel have been in the process of being studies, which is a variant of 316 stainless steel that is optimized for resistance to swelling. The D-9 samples are notable for the process in which a localized failure of the protective oxide layer becomes widespread corrosion. The research group is examining the D-9 samples using …

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)

This task is primarily focused on the evaluation of the effect of Si content on the susceptibility of modified 9Cr-1Mo-0.24V steel to stress corrosion cracking (SCC) and localized cracking in both molten lead-bismuth eutectic (LBE) and an aqueous solution of acidic pH.

Further, significant efforts are in progress to characterize the deformation mechanism of modified T91 grade steel as a function of temperature and strain rate. Simultaneously, surface analyses of the tested materials are ongoing using state-of-the-art techniques including scanning electron microscopy (SEM) and transmission electron microscopy (TEM).

Corrosion Barrier Development For Lbe Corrosion Resistance: Quarterly Report (April 2006), Biswajit Das

Transmutation Sciences Materials (TRP)

As reported in the last quarterly report, synthesis of Cr nanowires was found to be problematic in terms of uniform coverage. Hence Ni was identified as the alternative metal to form the nanowires. The purpose of the metal nanowires is to provide structural integrity to the nanoporous alumina, as well as a second defense mechanism against corrosion by oxidizing in case the top alumina layer is compromised. Nickel was selected due to its established electrochemical synthesis procedure. While Ni can provide very good structural integrity to the porous alumina, one potential problem is its higher dissolution rate in LBE. However, …

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

Transmutation Sciences Materials (TRP)

Advanced transmutation systems require structural materials that are able to withstand high neutron fluxes, high thermal cycling, and high resistance to chemical corrosion. The current candidate materials for such structures are ferritic and ferritic-martensitic steels due to their strong resistance to swelling, good microstructural stability under irradiation, and the retention of adequate ductility at typical reactor operating temperatures.

In parallel, lead bismuth eutectic (LBE) has emerged as a potential spallation target material for efficient production of neutrons, as well as a coolant in the accelerator system. While LBE has excellent properties as a nuclear coolant, it is also highly corrosive …

Neutron Multiplicity Measurements Of Target/Blanket Materials, 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 nuclear reactions in subcritical systems.

To design these systems, complex reactor physics computer codes and highly detailed data libraries are used to compute the reactivity of systems, reaction rates, destruction rates, …

Reactor Physics Studies For The Afci Reactor-Accelerator Coupling Experiments (Race) Project, Denis Beller

Transmutation Sciences Physics (TRP)

The specific research objective of this three-year project is to design and conduct an accelerator driven experiment. This experiment will help demonstrate in the U.S. the ability to design, compute, and conduct ADSS experiments; and to predict and measure source importance, coupling efficiency, sub-critical reactor kinetics and source-driven transients. In addition, databases will be created for both steady state and transient ADSS experiments for the nuclear community to develop and test new computational codes and methods, and the importance of a driving neutron source in various regions of different subcritical assemblies will be mapped. Experiments will be conducted and compared …

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

Separations Campaign (TRP)

The overall goal of this project is the creation of a framework that combines all the strengths of AMUSE’s complicated calculations, well-established commercial system process packages, and TRPSEMPro’s flexible parameter optimization modules. Development of the process simulation code can be done using the solvent extraction process at Argonne National Laboratory in collaboration with the UNLV Nevada Center for Advanced Computational Methods.

The major objectives are the following:

• Develop a framework for simulating the Spent Fuel Treatment Facility (SFTF) process using AMUSE code, commercial process package, such as ASPEN-PLUS, and system engineering model.
• Develop a middleware package that can communicate between …

Second Generation Waste Package Design Study, Sam Armijo, Mano Misra

Publications (YM)

The design of waste packages currently proposed for YMP is highly conservative. The candidate materials of construction of the waste packages and drip shields while highly corrosion resistant are extremely expensive and components made from these materials will require complex and expensive fabrication methods to assure their integrity. A proposed, second generation operating concept and waste package design, is intended to permit more efficient and less costly operation of the repository while maintaining waste package integrity. Major reductions in waste package costs can be realized by increasing the number of fuel assemblies stored in each waste package, eliminating the reference …

Interaction Between Metal Fission Products And Triso Coating Materials: A Study Of Chemical Bonding And Interdiffusion: 1st Quarterly Report, 2006, Clemens Heske

Fuels Campaign (TRP)

This project is devoted to an in-depth study of the chemical and electronic impact of metal fission products on the coating layers in TRISO nuclear fuel. In particular, there is a focus on the investigation of Pd, Cs, and Ag and their interface formation with SiC and carbon-based substrates. A variety of surface and near-surface bulk sensitive probes that investigate the occupied and unoccupied electronic states of the substrate and the metal overlayer have been utilized. By a controlled and stepwise deposition of the metal overlayer, it is possible to gain substantial insight into the formation of interfaces and their …

Interaction Between Metal Fission Products And Triso Coating Materials, Clemens Heske

Fuels Campaign (TRP)

In this project the chemical bonding and interface formation of metal fission products with the coating materials used in TRISO fuel particles is investigated. The interface formation of Pd, Cs, and Ag with SiC and pyrolytic carbon is studied in detail. Using the SiC single crystals and TRISO coating materials as substrates, interfaces are prepared under controlled conditions in an ultra-high vacuum environment and are studied with a photoelectron spectroscopy, Auger electron spectroscopy, Inverse Photoemission, X-ray emission spectroscopy, and X-ray absorption spectroscopy. Recent additions to the experimental approach include microscopic techniques (Transmission Electron Microscopy, Scanning Tunneling Microscopy, Atomic Force Microscopy) …

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

Fuels Campaign (TRP)

The safe and effective manufacturing of actinide-bearing fuels for any transmutation strategy requires that the entire manufacturing process be contained within a shielded hot cell environment. To ensure that the fabrication process is feasible, the entire process must be designed for remote operation. The equipment must be reliable enough to perform over several decades, and also easy to maintain or repair remotely. The facility must also be designed to facilitate its own decontamination and decommissioning. In addition to these design factors, the potential viability of any fuel fabrication process will also be impacted by a number of variables, such as …

Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix, Kenneth Czerwinski

Fuels Campaign (TRP)

This project examines inert 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 are 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 are synthesized and characterized based on the reactor physics results. The solubility of the fuel ceramics, in reactor conditions, reprocessing conditions, and repository conditions, are investigated in a manner to provide thermodynamic data necessary for …

Impact Of The Synthesis Process On Structure Properties For Afci Fuel Candidates, Thomas Hartmann

Fuels Campaign (TRP)

Advanced Fuel Cycle Initiative research on transmutation fuels includes mono-nitride ceramic fuel forms, and consists of closely coordinated “hot” actinide and “cold” inert and surrogate fuels work. Matrix and surrogate materials work involves three major components: (1) fuel matrix synthesis and fabrication, (2) fuel performance, and (3) fuel materials modeling. The synthesis and fabrication component supports basic material studies, as well as actinide fuel fabrication work through fuel fabrication process development. Fuel performance studies are examining the tolerance of nitride-type fuel to heavy irradiation damage. The fuel materials simulation work involves both atomistic and continuum scale modeling employing first principles, …

Solution-Based Synthesis Of Nitride Fuels, Kenneth Czerwinski, Thomas Hartmann

Fuels Campaign (TRP)

A wide variety of fuel concepts are considered for advanced reactor technology including metals, metal oxides or metal nitrides as solid solutions or composite materials. Nitride fuels have appropriate properties for advanced fuels including high thermal conductivity, thermal stability, solid-state solubility of actinides, fissile metal density, and suitable neutronic properties. A drawback of nitride fuels involves their synthesis. A key parameter for preparing oxide fuels is the precipitation step in the sol-gel process. For nitride fuels, the current synthetic route is carbothermic reduction from the oxide to the nitride. This process step is based on solid phase reactions and for …

Fundamental And Applied Experimental Investigations Of Corrosion Of Steel By Lbe Under Controlled Conditions: Kinetics, Chemistry Morphology, And Surface Preparation, John Farley, Allen L. Johnson, Dale L. Perry

Transmutation Sciences Materials (TRP)

Advanced nuclear processes such as the transmutation of nuclear waste, fast reactors, liquid-metal-cooled reactors, and spallation neutron sources require advanced materials systems to contain them. The required structural materials must be stable in the presence of nonmoderating coolants. A prime candidate for such a coolant is Lead Bismuth Eutectic (LBE). Materials in these systems must be able to tolerate high neutron fluxes, high temperatures, and chemical corrosion. Unfortunately, LBE corrodes stainless steel.

The corrosive behaviors of structural materials in LBE are not well understood. The Russians have over 80 reactor-years experience with LBE coolant in their Alpha-class submarine reactors. The …

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

Transmutation Sciences Materials (TRP)

The goal of this research project is to provide a basic understanding of the protective oxide layer behaviors and to develop oxide layer growth models of steels in non-isothermal lead alloys (lead or lead-bismuth eutectic) coolant systems. Precise studies and simulations of all hydrodynamics with thermal conditions encountered in practical coolant loop systems by use of different flowing conditions in the laboratory are difficult and expensive, if not impossible. Therefore it is important and necessary to develop theoretical models to predict the protective oxide layer behaviors at the design stage of a practical lead-alloy coolant system, to properly interpret and …