Nuclear Engineering Commons^™

Nevada Risk Assessment/Management Program – Phase 2 (Nramp2): Quarterly Progress Report July 1, 2007 Through September 30, 2007, Klaus J. Stetzenbach

Nevada Risk Assessment/Management Program

Work conducted in this 4th quarter consisted of 3 major activities:

• Continue the receipt and reconciliation of Area 5 Radioactive Waste Management Site (RWMS) inventory data.

• Receive, review, install, calibrate, and run the Goldsim Area 5 Performance Assessment (PA) Model, and review the supporting parameters and assumptions in the 93-document reference set as a tool for regulatory compliance and closure assessment.

• Identify, review, and compare the interpretation of pertinent regulatory guidelines and orders by DOE sites in compliance for PA, Compliance Assessment (CA), and closure activities - as they may relate to the Nevada Test Site (NTS) …

High Temperature Heat Exchanger Project: Quarterly Progress Report July 1, 2007 Through September 30, 2007, Anthony Hechanova

Publications (NSTD)

• Ceramatec Sulfuric Acid Decomposer. The numerical model of a SiC ceramic coupon with two layers of microchannels was developed. Calculations of the factor of safety and probability of failure for the case of a straight channel were performed. Results for a pressure of 7.5 MPa were performed. The thermal and mechanical stress analyses of the Ceramatec HTHX and decomposer were completed.

• Bayonet Heat Exchanger. The thermal and mechanical stress analyses of the bayonet type HTHX and decomposer (Sandia design) were completed. Temperature profiles obtained from thermocouples measured from the Sandia experiments have been applied to the whole packed …

Time Dependent Discrete Ordinates Neutron Transport Using Distribution Iteration In Xyz Geometry, James R. Dishaw

Theses and Dissertations

The DI algorithm is an alternative to source iteration that, in our testing, does not require an accelerator. I developed a formal verification plan and executed it to verify the results produced by my code that implemented DI with the above features. A new, matrix albedo, boundary condition treatment was developed and implemented so that infinite-medium benchmarks could be included in the verification test suite. The DI algorithm was modified for parallel efficiency and the prior instability of the refinement sweep was corrected. The testing revealed that DI performed as well or faster than source iteration with DSA and that …

Implementation Of Uncertainty Propagation In Triton/Keno: To Support The Global Nuclear Energy Partnership, Charlotta Sanders, Denis Beller

Reactor Campaign (TRP)

Monte Carlo methods are beginning to be used for three-dimensional fuel depletion analyses to compute various quantities of interest, including isotopic compositions of used fuel.1 The TRITON control module, available in the SCALE 5.1 code system, can perform three dimensional (3-D) depletion calculations using either the KENO V.a or KENO-VI Monte Carlo transport codes, as well as the two-dimensional (2- D) NEWT discrete ordinates code. For typical reactor systems, the neutron flux is not spatially uniform. For Monte Carlo simulations, this results in non-uniform statistical uncertainties in the computed reaction rates. For spatial regions where the flux is low, e.g., …

Monaco/Mavric Evaluation For Facility Shielding And Dose Rate Analysis: To Support The Global Nuclear Energy Partnership, Charlotta Sanders, Denis Beller

Reactor Campaign (TRP)

Monte Carlo methods are used to compute fluxes or dose rates over large areas using mesh tallies. For problems that demand that the uncertainty in each mesh cell be less than some set maximum, computation time is controlled by the cell with the largest uncertainty. This issue becomes quite troublesome in deep-penetration problems, and advanced variance reduction techniques are required to obtain reasonable uncertainties over large areas.

In this project the MAVRIC sequence will be evaluated along with the Monte Carlo engine Monaco to investigate its effectiveness and usefulness in facility shielding and dose rate analyses. A previously MCNP-evaluated cask …

Gnep Quarterly Input – Unlv July 1 Through September 30, 2007, 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 Global Nuclear Energy Partnership (GNEP) 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.

Unlv Research Foundation High Temperature Heat Exchanger Development: 9/08, Anthony Hechanova

Publications (NSTD)

Barriers addressed:

Nuclear Hydrogen Initiative R&D Plan – Material performance and component design and testing for the intermediate heat exchanger and high-temperature thermochemical water splitting (H₂SO₄ decomposition and HI decomposition). Improved materials for High Temperature Electrolysis.

Nevada Risk Assessment/Management Program (Nramp) – Phase 2: Quarterly Progress Report April 1, 2007 Through June 30, 2007, Klaus J. Stetzenbach

Nevada Risk Assessment/Management Program

Work conducted this quarter consisted of continuing the detailed data and information acquisition; review of the received document contents, and interpretation of significance in light of previous DOE documents. Much of the effort was devoted to reconciling inconsistencies and contradictions in both the primary data bases and in and among the DOE published documents. These review and reconciliation efforts included regular telephone and e-mail correspondence, as well as in-person discussions with DOE NVO personnel at the April DOE Generator Conference in Las Vegas. Reconciliation efforts continued with frequent (daily) exchanges on the inventory data sets, and the engineering descriptions of …

High Temperature Heat Exchanger Project: Quarterly Progress Report April 1, 2007 Through June 30, 2007, Anthony Hechanova

Publications (NSTD)

• Ceramatec Sulfuric Acid Decomposer. Modeling with different reacting flow channel configurations (ribbed-surface channels, hexagonal channels, and diamond-shaped channels) was performed. The probability of failure for the one channel geometry with different reacting flow channel configurations was calculated to be zero in the three principal directions for all of the cases.

• Bayonet Heat Exchanger. The Matlab code for calculating the probability of failure using a two-dimensional axisymmetric model of the bayonet decomposer was developed. The probability of failure was calculated for the inner and outer SiC walls, and the intermediate quartz wall of the decomposer and found to be …

Afci Quarterly Input – Unlv April 1 Through June 30, 2007, 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.

Reduced Shell Model Calculations Of 111Sb And 112Sb, E. Dikmen, T. Akyürek

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

The low-lying states of the mid-heavy odd-even 111Sb and odd-odd 112Sb isotopes are calculated for the first time within the shell model framework. The shell model calculations have been carried out within the reduced model space including the single particle orbits 1d5/2, 0g7/2, 1d3/2, 2s1/2. We obtain the energy spectra for the 111Sb and 112Sb isotopes in the reduced model space by using CD-Bonn two-body effective nucleon-nucleon interaction. The energy spectra are compared to the experimental results to give some discussion about the low-lying states of 111Sb and 112Sb. © 2007 Chinese Physical Society and IOP Publishing Ltd.

Nevada Risk Assessment/Management Program (Nramp) – Phase 2: Quarterly Progress Report January 1, 2007 Through March 31, 2007, Klaus J. Stetzenbach

Nevada Risk Assessment/Management Program

Work conducted in this second quarter consisted of continuing the detailed data and information acquisition; review of the received document contents, and interpretation of significance in light of previous DOE documents. This included telephone and in-person discussions with DOE NVO personnel at the March Waste Management Symposia in Tucson. As a result of these discussions and review of the supporting data and methodologies, a more specific listing of activities was developed, and DOE provided a confirmatory note to HRC in March.

Much of the review of the received information does indicate significant changes in data, methodologies, and baseline assumptions over …

High Temperature Heat Exchanger Project: Quarterly Progress Report January 1, 2007 Through March 31, 2007, Anthony Hechanova

Publications (NSTD)

• The variation of sulfur dioxide production (throughput) of the baseline design of the Ceramatec sulfuric acid decomposer with total mass flow rate of reacting flow has been calculated. According to the calculations, the sulfur dioxide production increases as the total mass flow rate of reacting flow increases regardless of the fact that decomposition percentage of sulfuric trioxide decreases. A parametric study of the baseline design of the Ceramatec sulfuric acid decomposer was performed.

• The thermal performance using various channel geometries for the decomposer was studied. The baseline design (straight channels) has 89.5% thermal efficiency while the thermal efficiency …

Afci Quarterly Input – Unlv January 1 Through March 31, 2007, 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.

A Multireference Density Functional Approach To The Calculation Of The Excited States Of Uranium Ions, Eric V. Beck

Theses and Dissertations

An accurate and efficient hybrid Density Functional Theory (DFT)/Multireference Configuration Interaction (MRCI) model for computing electronic excitation energies in heavy element atoms and molecules was developed. This model incorporated relativistic effects essential for accurate qualitative and quantitative spectroscopic predictions on heavy elements, while simultaneously removing spin-multiplicity limitations inherent in the original model on which it is based. This model was used to successfully compute ground and low-lying electronic states for atoms in the first two rows of the period table, which were used for calibration. Once calibrated, calculations on carbon monoxide, bromine fluoride, the bromine atom, uranium +4 and +5 …

Precise Calculation Of Complex Radioactive Decay Chains, Logan J. Harr

Theses and Dissertations

This thesis documents a new approach to investigate the gamma radiation activity of the fission products of three different fuels (U-235, U-238, and U-239) exposed to three different incident neutron energy spectra (thermal, fast spectrum, and high energies). An application of the exponential moments function is used with a transmutation matrix in the calculation of complex radioactive decay chains to achieve greater precision than can be attained through current methods. The result of this research is a code which can calculate the decay products from complex radioactive decay chains with a high degree of precision while quantifying the uncertainty in …

High Resolution Mesoscale Weather Data Improvement To Spatial Effects For Doserate Contour Plot Predictions, Christopher P. Jones

Theses and Dissertations

Reanalysis weather data is obtained for dates surrounding historical nuclear tests and processed through Regional Atmospheric Modeling System (RAMS) software to produce a high-resolution weather forecast. Output from RAMS is visualized to check for validity and input into Hazard Prediction and Assessment Capability (HPAC) software and modeled predictions are compared to historical observation data. Simulations are conducted using constant high resolution weather and varying terrain resolution. The HPAC prediction is numerically compared to historical observation data. The result of this research culminated in the knowledge that early-time, low-altitude wind data was neglected by HPAC's incorporation of the Defense Land Fallout …

Condition Reporting And Resolution, J. M. Pesek, S. A. Wade

Publications (YM)

This procedure facilitates a safety conscious work environment by providing a mechanism for employees to make management aware of existing and potential conditions. This procedure establishes the responsibilities and process to be used to ensure that conditions related to, but not limited to, the environment, safety, health, waste isolation, operations, security, or quality of items and services associated with Office of Civilian Radioactive Waste Management (OCRWM) work activities are promptly identified, controlled, evaluated, and corrected as soon as practical. This procedure describes the process flow, controls, interfaces, and requirements for condition identification and resolution. This includes adverse conditions as well …

Nevada Risk Assessment/Management Program (Nramp) – Phase 2: Quarterly Progress Report, Oct. 1, 2006- Dec. 31, 2006, Klaus J. Stetzenbach

Nevada Risk Assessment/Management Program

Work conducted in this initial period consisted of work start-up (technical, administrative, contractual), and interviewing/site visits with DOE NVO staff (and support contractors) and HRC staff to quickly ascertain current technical activities and priorities as related to the scope of this task.

Since much of the technical work scope builds on previous technical work, it was considered critical to determine the changes (programmatic, technical, and regulatory) that have occurred over the past several years that directly relate to the scope. It was also equally important to determine the technical and programmatic priorities that have been established in the interim.

High Temperature Heat Exchanger Project: Quarterly Progress Report October 1, 2006 Through December 31, 2006, Anthony Hechanova

Publications (NSTD)

Modifications to the single-channel models of the Ceramatec heat exchanger and decomposer concept for hexagonal flow channels under two values of layer-overlapping (50% and 100%) and for diamond-shaped flow channels were completed.

The finite element calculations of the “Ball on Three Ball Test” for ceramic material for the purpose of selecting the appropriate specimen thickness for future experimental testing was performed for plate thicknesses ranging from 2 to 8 mm.

A finite element model of the “Ball on Three Ball Test” was also studied for discs having micro-channels.

Environmental Effects On Corrosion Properties Of Alloy 22, Mano Misra, L. G. Mcmillion

Publications (YM)

Subtask 1: Experimental Determination of Parameters for the General Corrosion Model Subtask 2: Corrosion Under Dust Deposits Containing Hygroscopic Salts Subtask 3: Heated Electrode Approach for the Study of Corrosion Under Aggressive Conditions Subtask 4: Effect of Hydrogen Permeation on the Stability of the Passive Film of Alloy 22

Phase Stability And Segregation In Alloy 22 Base Metal And Weldments, Jeffrey Lacombe, G. L. Mcmillon

Publications (YM)

Subtask 1: Microstructural Characterization of Phase Stability and Variability in Alloy 22. Develop an improved understanding of Alloy 22 and the extent to which compositional and microstructural variations are present in otherwise “nominal” as-procured material. Subtask 2: Electrochemical Methods to Detect Susceptibility of Alloy 22 to Localized Corrosion. Study the influence that compositional and microstructural variations have on the corrosion performance of Alloy 22.

Geometrical Modeling Of Fibrous Materials Under Compression, Benoit Maze, Hooman Vahedi Tafreshi, Behnam Pourdeyhimi

Mechanical and Nuclear Engineering Publications

Many fibrous materials such as nonwovens are consolidated via compaction rolls in a so-called calendering process. Hot rolls compress the fiber assembly and cause fiber-to-fiber bonding resulting in a strong yet porous structure. In this paper, we describe an algorithm for generating three dimensional virtual fiberwebs and simulating the geometrical changes that happen to the structure during the calendering process. Fibers are assumed to be continuous filaments with square cross sections lying randomly in the x or y direction. The fibers are assumed to be flexible to allow bending over one another during the compression process. Lateral displacement is not …

An Electrospray-Based, Ozone-Free Air Purification Technology, Gary Tepper, Royal Kessick, Dmitry Pestov

Mechanical and Nuclear Engineering Publications

A zero-pressure-drop, ozone-free air purification technology is reported. Contaminated air was directed into a chamber containing an array of electrospray wick sources. The electrospray sources produce an aerosol of tiny, electrically charged aqueous droplets.Charge was transferred from the droplets onto polar and polarizable species in the contaminated air stream and the chargedcontaminants were extracted using an electric field and deposited onto a metal surface. Purified air emerged from the other end of the chamber. The very small aqueous electrospray droplets completely evaporate so that the process is essentially dry and no liquid solvent is collected or recirculated. The air purification …

Thermal Transient Flow Rate Sensor For High Temperature Liquid Metal Cooled Nuclear Reactor, Yingtao Jiang, Jian Ma, Rohit Reddy Saddi

Mechanical Engineering Faculty Research

In nuclear power plants and accelerator driven system (ADS) for nuclear waste treatment, it is important to monitor the coolant flow rate in the reactor core and pipe-line. In such a strong irradiation, high pressure and temperature environment, no accurate local flow measurement technique is readily available. Electromagnetic (EM) flow meter is popular in low temperature application as it is a non-intrusive technology. However, additional voltage will be produced due to temperature, flow, pressure, the chemical properties of the liquid metal and surface condition of the steel walls. In addition, the non-definite wetting behavior of liquid lead-bismuth to the electrically …

Decoupling And Disturbance Rejection Control For Target Circulation, Jian Ma, Joon S. Lee, Woosoon Yim

Reactor Campaign (TRP)

In 1998, the Institute of Physics and Power Engineering (IPPE) and Experimental and Development Organization “Gidropress” in Russia, began the design and construction of a prototype lead-bismuth eutectic (LBE) accelerator target, the Target Complex 1 (TC-1), under the International Science and Technology Center (ISTC) project #559 (“Pilot Flow Lead-Bismuth Target of 1 MW Power for Accelerator Driven Systems”) in support of the international efforts to develop accelerator-driven spallation systems for nuclear transmutation and other applications.

During the thermal and engineering test of the TC-1 in 2005 at UNLV, it was observed that the existing control algorithm led to a very …

Modeling And Design Algorithms For Electromagnetic Pumps, Daniel P. Cook

Reactor Campaign (TRP)

Electromagnetic (EM) induction pumps are used in a number of nuclear energy related applications, such as circulation of molten lead-bismuth eutectic alloys in neutron targets, and circulation of liquid sodium metal in Gen IV Sodium-cooled Fast Reactors (SFR). Because EM pumps have no moving parts which can fail, they are considerably more reliable than conventional mechanical pumps for molten metal usage, and thus EM pumps are favored over mechanical pumps even though their pumping efficiency is lower and their initial cost is higher when compared to mechanical pumps of similar flow rates.

The research objectives of this task are:

• A …

Thermal Transient Flow Rate Sensor For High Temperature Liquid Metal Cooled Nuclear Reactor, Yingtao Jiang

Reactor Campaign (TRP)

In nuclear power plants and accelerator driven system (ADS) for nuclear waste treatment, it is important to monitor the coolant flow rate in the reactor core and pipe-line. In such a strong irradiation, high pressure and temperature environment, no accurate local flow measurement technique is readily available. Electromagnetic (EM) flow meter is popular in low temperature application as it is a non-intrusive technology. However, additional voltage will be produced due to temperature, flow, pressure, the chemical properties of the liquid metal and surface condition of the steel walls. In addition, the non-definite wetting behavior of liquid lead-bismuth to the electrically …

University Of Nevada, Las Vegas Transmutation Research Program Annual Report Academic Year 2006-2007, Anthony Hechanova, Rebecca Arbour

Transmutation Research Program Reports (TRP)

It is my pleasure to present the UNLV Transmutation Research Program’s sixth annual report that highlights the academic year 2006-2007. Supporting this document are the many technical reports and theses that have been generated over the past five years.

In the sixth year of our program, we continued to see growth in the Radiochemistry Ph.D. program with a total of 13 students in the third year of the program (we anticipated eight in the program proposal). Since our inception, the program has sponsored to their conclusion 42 M.S. and 4 Ph.D. degrees. The program supported 39 graduate students, 17 undergraduates, …

Combined Radiation Detection Methods For Assay Of Higher Actinides In Separation Processes, 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 …