CO (Carbon Monoxide Mixing Ratio System) Handbook (open access)

CO (Carbon Monoxide Mixing Ratio System) Handbook

The main function of the CO instrument is to provide continuous accurate measurements of carbon monoxide mixing ratio at the ARM SGP Central Facility (CF) 60-meter tower (36.607 °N, 97.489 °W, 314 meters above sea level). The essential feature of the control and data acquisition system is to record signals from a Thermo Electron 48C and periodically calibrate out zero and span drifts in the instrument using the combination of a CO scrubber and two concentrations of span gas (100 and 300 ppb CO in air). The system was deployed on May 25, 2005.
Date: February 23, 2011
Creator: Biraud, S
Object Type: Report
System: The UNT Digital Library
A COMPARISON OF HANFORD AND SAVANNAH RIVER SITE HIGH-LEVEL WASTES (open access)

A COMPARISON OF HANFORD AND SAVANNAH RIVER SITE HIGH-LEVEL WASTES

This study is a simple comparison of high-level waste from plutonium production stored in tanks at the Hanford and Savannah River sites. Savannah River principally used the PUREX process for plutonium separation. Hanford used the PUREX, Bismuth Phosphate, and REDOX processes, and reprocessed many wastes for recovery of uranium and fission products. Thus, Hanford has 55 distinct waste types, only 17 of which could be at Savannah River. While Hanford and Savannah River wastes both have high concentrations of sodium nitrate, caustic, iron, and aluminum, Hanford wastes have higher concentrations of several key constituents. The factors by which average concentrations are higher in Hanford salt waste than in Savannah River waste are 67 for {sup 241}Am, 4 for aluminum, 18 for chromium, 10 for fluoride, 8 for phosphate, 6 for potassium, and 2 for sulfate. The factors by which average concentrations are higher in Hanford sludges than in Savannah River sludges are 3 for chromium, 19 for fluoride, 67 for phosphate, and 6 for zirconium. Waste composition differences must be considered before a waste processing method is selected: A method may be applicable to one site but not to the other.
Date: February 23, 2011
Creator: PHILIP, HILL RC; JG, REYNOLDS & PL, RUTLAND
Object Type: Article
System: The UNT Digital Library
Energy Balance Bowen Ratio Station (EBBR) Handbook (open access)

Energy Balance Bowen Ratio Station (EBBR) Handbook

The energy balance Bowen ratio (EBBR) system produces 30-minute estimates of the vertical fluxes of sensible and latent heat at the local surface. Flux estimates are calculated from observations of net radiation, soil surface heat flux, and the vertical gradients of temperature and relative humidity (RH). Meteorological data collected by the EBBR are used to calculate bulk aerodynamic fluxes, which are used in the Bulk Aerodynamic Technique (BA) EBBR value-added product (VAP) to replace sunrise and sunset spikes in the flux data. A unique aspect of the system is the automatic exchange mechanism (AEM), which helps to reduce errors from instrument offset drift.
Date: February 23, 2011
Creator: Cook, DR
Object Type: Report
System: The UNT Digital Library
Energy Efficiency of Distributed Environmental Control Systems (open access)

Energy Efficiency of Distributed Environmental Control Systems

In this report, we present an analytical evaluation of the potential of occupant-regulated distributed environmental control systems (DECS) to enhance individual occupant thermal comfort in an office building with no increase, and possibly even a decrease in annual energy consumption. To this end we developed and applied several analytical models that allowed us to optimize comfort and energy consumption in partitioned office buildings equipped with either conventional central HVAC systems or occupant-regulated DECS. Our approach involved the following interrelated components: 1. Development of a simplified lumped-parameter thermal circuit model to compute the annual energy consumption. This was necessitated by the need to perform tens of thousands of optimization calculations involving different US climatic regions, and different occupant thermal preferences of a population of ~50 office occupants. Yearly transient simulations using TRNSYS, a time-dependent building energy modeling program, were run to determine the robustness of the simplified approach against time-dependent simulations. The simplified model predicts yearly energy consumption within approximately 0.6% of an equivalent transient simulation. Simulations of building energy usage were run for a wide variety of climatic regions and control scenarios, including traditional “one-size-fits-all” (OSFA) control; providing a uniform temperature to the entire building, and occupant-selected “have-it-your-way” (HIYW) control …
Date: February 23, 2011
Creator: Khalifa, H. Ezzat; Isik, Can & Dannenhoffer, John F. III
Object Type: Report
System: The UNT Digital Library
Laboratory and Modeling Evaluations in Support of Field Testing for Desiccation at the Hanford Site (open access)

Laboratory and Modeling Evaluations in Support of Field Testing for Desiccation at the Hanford Site

The Deep Vadose Zone Treatability Test Plan for the Hanford Central Plateau includes testing of the desiccation technology as a potential technology to be used in conjunction with surface infiltration control to limit the flux of technetium and other contaminants in the vadose zone to the groundwater. Laboratory and modeling efforts were conducted to investigate technical uncertainties related to the desiccation process and its impact on contaminant transport. This information is intended to support planning, operation, and interpretation of a field test for desiccation in the Hanford Central Plateau.
Date: February 23, 2011
Creator: Truex, Michael J.; Oostrom, Martinus; Freedman, Vicky L.; Strickland, Christopher E.; Wietsma, Thomas W.; Tartakovsky, Guzel D. et al.
Object Type: Report
System: The UNT Digital Library
A PROTOTYPE FOUR INCH SHORT HYDRIDE (FISH) BED AS A REPLACEMENT TRITIUM STORAGE BED (open access)

A PROTOTYPE FOUR INCH SHORT HYDRIDE (FISH) BED AS A REPLACEMENT TRITIUM STORAGE BED

The Savannah River Site (SRS) tritium facilities have used 1st generation (Gen1) metal hydride storage bed assemblies with process vessels (PVs) fabricated from 3 inch nominal pipe size (NPS) pipe to hold up to 12.6 kg of LaNi{sub 4.25}Al{sub 0.75} metal hydride for tritium gas absorption, storage, and desorption for over 15 years. The 2nd generation (Gen2) of the bed design used the same NPS for the PV, but the added internal components produced a bed nominally 1.2 m long, and presented a significant challenge for heater cartridge replacement in a footprint limited glove-box. A prototype 3rd generation (Gen3) metal hydride storage bed has been designed and fabricated as a replacement candidate for the Gen2 storage bed. The prototype Gen3 bed uses a PV pipe diameter of 4 inch NPS so the bed length can be reduced below 0.7 m to facilitate heater cartridge replacement. For the Gen3 prototype bed, modeling results show increased absorption rates when using hydrides with lower absorption pressures. To improve absorption performance compared to the Gen2 beds, a LaNi{sub 4.15}Al{sub 0.85} material was procured and processed to obtain the desired pressure-composition-temperature (PCT) properties. Other bed design improvements are also presented.
Date: February 23, 2011
Creator: Klein, J.; Estochen, E.; Shanahan, K. & Heung, L.
Object Type: Article
System: The UNT Digital Library
A survey on wind power ramp forecasting. (open access)

A survey on wind power ramp forecasting.

The increasing use of wind power as a source of electricity poses new challenges with regard to both power production and load balance in the electricity grid. This new source of energy is volatile and highly variable. The only way to integrate such power into the grid is to develop reliable and accurate wind power forecasting systems. Electricity generated from wind power can be highly variable at several different timescales: sub-hourly, hourly, daily, and seasonally. Wind energy, like other electricity sources, must be scheduled. Although wind power forecasting methods are used, the ability to predict wind plant output remains relatively low for short-term operation. Because instantaneous electrical generation and consumption must remain in balance to maintain grid stability, wind power's variability can present substantial challenges when large amounts of wind power are incorporated into a grid system. A critical issue is ramp events, which are sudden and large changes (increases or decreases) in wind power. This report presents an overview of current ramp definitions and state-of-the-art approaches in ramp event forecasting.
Date: February 23, 2011
Creator: Ferreira, C.; Gama, J.; Matias, L.; Botterud, A.; Wang, J. (Decision and Information Sciences) & Porto), (INESC
Object Type: Report
System: The UNT Digital Library
VAP Development: Initiation, Development, Evaluation, and Release (open access)

VAP Development: Initiation, Development, Evaluation, and Release

This white paper provides a plan to formalize the evaluation of newly developed VAPs and a framework for the development of value-added products through four different stages: Initiation, Development, Evaluation, and Release.
Date: February 23, 2011
Creator: Jensen, M.; Collis, S.; Flynn, C.; Mather, J.; McFarlane, S.; Monroe, J. et al.
Object Type: Report
System: The UNT Digital Library
Accurate Alignment of Plasma Channels Based on Laser Centroid Oscillations (open access)

Accurate Alignment of Plasma Channels Based on Laser Centroid Oscillations

A technique has been developed to accurately align a laser beam through a plasma channel by minimizing the shift in laser centroid and angle at the channel outptut. If only the shift in centroid or angle is measured, then accurate alignment is provided by minimizing laser centroid motion at the channel exit as the channel properties are scanned. The improvement in alignment accuracy provided by this technique is important for minimizing electron beam pointing errors in laser plasma accelerators.
Date: March 23, 2011
Creator: Gonsalves, Anthony; Nakamura, Kei; Lin, Chen; Osterhoff, Jens; Shiraishi, Satomi; Schroeder, Carl et al.
Object Type: Article
System: The UNT Digital Library
Electromagnetic Transport From Microtearing Mode Turbulence (open access)

Electromagnetic Transport From Microtearing Mode Turbulence

This Letter presents non-linear gyrokinetic simulations of microtearing mode turbulence. The simulations include collisional and electromagnetic effects and use experimental parameters from a high beta discharge in the National Spherical Torus Experiment (NSTX). The predicted electron thermal transport is comparable to that given by experimental analysis, and it is dominated by the electromagnetic contribution of electrons free streaming along the resulting stochastic magnetic field line trajectories. Experimental values of flow shear can significantly reduce the predicted transport.
Date: March 23, 2011
Creator: Guttenfelder, W.; Candy, J.; Kaye, S. M.; Nevins, W. M.; Wang, E.; Bell, R. E. et al.
Object Type: Report
System: The UNT Digital Library
Environment, Safety and Health Self-Assessment Report Fiscal Year 2010 (open access)

Environment, Safety and Health Self-Assessment Report Fiscal Year 2010

The Lawrence Berkeley National Laboratory (LBNL) Environment, Safety, and Health (ES&H) Self-Assessment Program was established to ensure that Integrated Safety Management (ISM) is implemented institutionally and by all divisions. The ES&H Self-Assessment Program, managed by the Office of Contractor Assurance (OCA), provides for an internal evaluation of all ES&H programs and systems at LBNL. The primary objective of the program is to ensure that work is conducted safely and with minimal negative impact to workers, the public, and the environment. Self-assessment follows the five core functions and guiding principles of ISM. Self-assessment is the mechanism used to promote the continuous improvement of the Laboratory's ES&H programs. The process is described in the Environment, Safety, and Health Assurance Plan (PUB-5344) and is composed of three types of self-assessments: Division ES&H Self-Assessment, ES&H Technical Assurance Program Assessment, and Division ES&H Peer Review. The Division ES&H Self-Assessment Manual (PUB-3105) provides the framework by which divisions conduct formal ES&H self-assessments to systematically identify program deficiencies. Issue-specific assessments are designed and implemented by the divisions and focus on areas of interest to division management. They may be conducted by teams and involve advance planning to ensure that appropriate resources are available. The ES&H Technical Assurance …
Date: March 23, 2011
Creator: Robinson, Scott
Object Type: Report
System: The UNT Digital Library
A HIGH CURRENT DENSITY LI+ ALUMINO-SILICATE ION SOURCE FOR TARGET HEATING EXPERIMENTS (open access)

A HIGH CURRENT DENSITY LI+ ALUMINO-SILICATE ION SOURCE FOR TARGET HEATING EXPERIMENTS

The NDCX-II accelerator for target heating experiments has been designed to use a large diameter ({approx_equal} 10.9 cm) Li{sup +} doped alumino-silicate source with a pulse duration of 0.5 {micro}s, and beam current of {approx_equal} 93 mA. Characterization of a prototype lithium alumino-silicate sources is presented. Using 6.35mm diameter prototype emitters (coated on a {approx_equal} 75% porous tungsten substrate), at a temperature of {approx_equal} 1275 C, a space-charge limited Li{sup +} beam current density of {approx_equal} 1 mA/cm{sup 2} was measured. At higher extraction voltage, the source is emission limited at around {approx_equal} 1.5 mA/cm{sup 2}, weakly dependent on the applied voltage. The lifetime of the ion source is {approx_equal} 50 hours while pulsing the extraction voltage at 2 to 3 times per minute. Measurements show that the life time of the ion source does not depend only on beam current extraction, and lithium loss may be dominated by neutral loss or by evaporation. The life time of a source is around {ge} 10 hours in a DC mode extraction, and the extracted charge is {approx_equal} 75% of the available Li in the sample. It is inferred that pulsed heating may increase the life time of a source.
Date: March 23, 2011
Creator: Roy, Prabir K.; Greenway, Wayne G.; Kwan, Joe W.; Seidl, Peter A. & Waldron, William L.
Object Type: Article
System: The UNT Digital Library
LLNL Contribution to Sandia Used Fuel Disposition - Security March 2011 Deliverable (open access)

LLNL Contribution to Sandia Used Fuel Disposition - Security March 2011 Deliverable

Cleary [2007] divides the proliferation pathway into stages: diversion, facility misuse, transportation, transformation, and weapons fabrication. King [2010], using Cleary's methodology, compares a deepburn fusion-driven blanket containing weapons-grade plutonium with a PWR burning MOX fuel enrichments of 5-9%. King considers the stages of theft, transportation, transformation, and nuclear explosive fabrication. In the current study of used fuel storage security, a similar approach is appropriate. First, one must consider the adversary's objective, which can be categorized as on-site radionuclide dispersion, theft of material for later radionuclide dispersion, and theft of material for later processing and fabrication into a nuclear explosive. For on-site radionuclide dispersion, only a single proliferation pathway stage is appropriate: dispersion. That situation will be addressed in future reports. For later radionuclide dispersion, the stages are theft, transportation, and transformation (from oxide spent fuel containing both fission products and actinides to a material size and shape suitable for dispersion). For later processing and fabrication into a nuclear explosive, the stages are theft (by an outsider or by facility misuse by an insider), transportation, transformation (from oxide spent fuel containing both fission products and actinides to a metal alloy), and fabrication (of the alloy into a weapon). It should be …
Date: March 23, 2011
Creator: Blink, J. A.
Object Type: Report
System: The UNT Digital Library
A Next Generation Light Source Facility at LBNL (open access)

A Next Generation Light Source Facility at LBNL

The Next Generation Light Source (NGLS) is a design concept, under development at LBNL, for a multibeamline soft x-ray FEL array powered by a ~;;2 GeV superconducting linear accelerator, operating with a 1 MHz bunch repetition rate. The CW superconducting linear accelerator is supplied by a high-brightness, highrepetition- rate photocathode electron gun. Electron bunches are distributed from the linac to the array of independently configurable FEL beamlines with nominal bunch rates up to 100 kHz in each FEL, and with even pulse spacing. Individual FELs may be configured for EEHG, HGHG, SASE, or oscillator mode of operation, and will produce high peak and average brightness x-rays with a flexible pulse format, with pulse durations ranging from sub-femtoseconds to hundreds of femtoseconds.
Date: March 23, 2011
Creator: Corlett, J. N.; Austin, B.; Baptiste, K. M.; Byrd, J. M.; Denes, P.; Donahue, R. et al.
Object Type: Article
System: The UNT Digital Library
Two-dimensional Imaging Velocity Interferometry: Technique and Data Analysis (open access)

Two-dimensional Imaging Velocity Interferometry: Technique and Data Analysis

We describe the data analysis procedures for an emerging interferometric technique for measuring motion across a two-dimensional image at a moment in time, i.e. a snapshot 2d-VISAR. Velocity interferometers (VISAR) measuring target motion to high precision have been an important diagnostic in shockwave physics for many years Until recently, this diagnostic has been limited to measuring motion at points or lines across a target. We introduce an emerging interferometric technique for measuring motion across a two-dimensional image, which could be called a snapshot 2d-VISAR. If a sufficiently fast movie camera technology existed, it could be placed behind a traditional VISAR optical system and record a 2d image vs time. But since that technology is not yet available, we use a CCD detector to record a single 2d image, with the pulsed nature of the illumination providing the time resolution. Consequently, since we are using pulsed illumination having a coherence length shorter than the VISAR interferometer delay ({approx}0.1 ns), we must use the white light velocimetry configuration to produce fringes with significant visibility. In this scheme, two interferometers (illuminating, detecting) having nearly identical delays are used in series, with one before the target and one after. This produces fringes with at …
Date: March 23, 2011
Creator: Erskine, D. J.; Smith, R. F.; Bolme, C.; Celliers, P. & Collins, G.
Object Type: Article
System: The UNT Digital Library
Ab Initio Many-Body Calculation of the 7Be(p,g)8B Radiative Capture (open access)

Ab Initio Many-Body Calculation of the 7Be(p,g)8B Radiative Capture

None
Date: May 23, 2011
Creator: Navratil, P; Roth, R & Quaglioni, S
Object Type: Article
System: The UNT Digital Library
Characterization of Fish Passage Conditions through a Francis Turbine and Regulating Outlet at Cougar Dam, Oregon, Using Sensor Fish, 2009–2010 (open access)

Characterization of Fish Passage Conditions through a Francis Turbine and Regulating Outlet at Cougar Dam, Oregon, Using Sensor Fish, 2009–2010

Fish passage conditions through a Francis turbine and a regulating outlet (RO) at Cougar Dam on the south fork of the McKenzie River in Oregon were evaluated by Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers, Portland District, using Sensor Fish devices. The objective of the study was to describe and compare passage exposure conditions, identifying potential fish injury regions encountered during passage via specific routes. The RO investigation was performed in December 2009 and the turbine evaluation in January 2010, concurrent with HI-Z balloon-tag studies by Normandeau Associates, Inc. Sensor Fish data were analyzed to estimate 1) exposure conditions, particularly exposure to severe collision, strike, and shear events by passage route sub-regions; 2) differences in passage conditions between passage routes; and 3) relationships to live-fish injury and mortality data estimates. Comparison of the three passage routes evaluated at Cougar Dam indicates that the RO passage route through the 3.7-ft gate opening was relatively the safest route for fish passage under the operating conditions tested; turbine passage was the most deleterious. These observations were supported also by the survival and malady estimates obtained from live-fish testing. Injury rates were highest for turbine passage. Compared to mainstem Columbia …
Date: May 23, 2011
Creator: Duncan, Joanne P.
Object Type: Report
System: The UNT Digital Library
Combined Ideal and Kinetic Effects on Reversed Shear Alfven Eigenmodes (open access)

Combined Ideal and Kinetic Effects on Reversed Shear Alfven Eigenmodes

A theory of Reversed Shear Alfven Eigenmodes (RSAEs) is developed for reversed magnetic field shear plasmas when the safety factor minimum, qmin, is at or above a rational value. The modes we study are known sometimes as either the bottom of the frequency sweep or the down sweeping RSAEs. We show that the ideal MHD theory is not compatible with the eigenmode solution in the reversed shear plasma with qmin above integer values. Corrected by special analytic FLR condition MHD dispersion of these modes nevertheless can be developed. Large radial scale part of the analytic RSAE solution can be obtained from ideal MHD and expressed in terms of the Legendre functions. The kinetic equation with FLR effects for the eigenmode is solved numerically and agrees with the analytic solutions. Properties of RSAEs and their potential implications for plasma diagnostics are discussed.
Date: May 23, 2011
Creator: N.N. Gorelenkov, G.J. Kramer, and R. Nazikian
Object Type: Report
System: The UNT Digital Library
Comment on Li pellet Conditioning in TFTR (open access)

Comment on Li pellet Conditioning in TFTR

Li pellet conditioning in TFTR results in a reduction of the edge electron density which allows increased neutral beam penetration, central heating, and fueling. Consequently the temperature profiles became more peaked with higher central Ti, Te, and neutron emission rates.
Date: May 23, 2011
Creator: Budny, R.V.
Object Type: Report
System: The UNT Digital Library
Computational fluid dynamics analyses of lateral heat conduction, coolant azimuthal mixing and heat transfer predictions in a BR2 fuel assembly geometry. (open access)

Computational fluid dynamics analyses of lateral heat conduction, coolant azimuthal mixing and heat transfer predictions in a BR2 fuel assembly geometry.

To support the analyses related to the conversion of the BR2 core from highly-enriched (HEU) to low-enriched (LEU) fuel, the thermal-hydraulics codes PLTEMP and RELAP-3D are used to evaluate the safety margins during steady-state operation (PLTEMP), as well as after a loss-of-flow, loss-of-pressure, or a loss of coolant event (RELAP). In the 1-D PLTEMP and RELAP simulations, conduction in the azimuthal and axial directions is not accounted. The very good thermal conductivity of the cladding and the fuel meat and significant temperature gradients in the lateral directions (axial and azimuthal directions) could lead to a heat flux distribution that is significantly different than the power distribution. To evaluate the significance of the lateral heat conduction, 3-D computational fluid dynamics (CFD) simulations, using the CFD code STAR-CD, were performed. Safety margin calculations are typically performed for a hot stripe, i.e., an azimuthal region of the fuel plates/coolant channel containing the power peak. In a RELAP model, for example, a channel between two plates could be divided into a number of RELAP channels (stripes) in the azimuthal direction. In a PLTEMP model, the effect of azimuthal power peaking could be taken into account by using engineering factors. However, if the thermal mixing …
Date: May 23, 2011
Creator: Tzanos, C. P. & Dionne, B. (Nuclear Engineering Division)
Object Type: Report
System: The UNT Digital Library
Considerations for Contractile Electroactive Materials and Actuators (open access)

Considerations for Contractile Electroactive Materials and Actuators

Ras Labs produces contractile electroactive polymer (EAP) based materials and actuators that bend, swell, ripple, and contract (new development) with low electric input. In addition, Ras Labs produces EAP materials that quickly contract and expand, repeatedly, by reversing the polarity of the electric input, which can be cycled. This phenomenon was explored using molecular modeling, followed by experimentation. Applied voltage step functions were also investigated. High voltage steps followed by low voltage steps produced a larger contraction followed by a smaller contraction. Actuator control by simply adjusting the electric input is extremely useful for biomimetic applications. Muscles are able to partially contract. If muscles could only completely contract, nobody could hold an egg, for example, without breaking it. A combination of high and low voltage step functions could produce gross motor function and fine manipulation within the same actuator unit. Plasma treated electrodes with various geometries were investigated as a means of providing for more durable actuation.
Date: May 23, 2011
Creator: Lenore Rasmussen, David Schramm, Paul Rasmussen, Kevin Mullaly, Ras Labs, LLC, Intelligent Materials for Prosthetics & Automation, Lewis D. Meixler, Daniel Pearlman and Alice Kirk
Object Type: Article
System: The UNT Digital Library

Economic Development from Gigawatt-Scale Wind Deployment in Wyoming

This presentation provides an overview of economic development in Wyoming from gigawatt-scale wind development and includes a discussion of project context, definitions and caveats, a deployment scenario, modeling inputs, results, and conclusions.
Date: May 23, 2011
Creator: Lantz, E.
Object Type: Presentation
System: The UNT Digital Library
Ekpyrosis and inflationary dynamics in heavy ion collisions: the role of quantum fluctuations (open access)

Ekpyrosis and inflationary dynamics in heavy ion collisions: the role of quantum fluctuations

We summarize recent significant progress in the development of a first-principles formalism to describe the formation and evolution of matter in very high energy heavy ion collisions. The key role of quantum fluctuations both before and after a collision is emphasized. Systematic computations are now feasible to address early time isotropization, flow, parton energy loss and the Chiral Magnetic Effect.
Date: May 23, 2011
Creator: Dusling, K.; Venugopalan, R. & Gelis, F.
Object Type: Article
System: The UNT Digital Library
Estimation of Steady-State and Transcient Power Distributions for the RELAP Analyses of the 1963 Loss-Of-Flow and Loss-Of-Pressure Tests at br2. (open access)

Estimation of Steady-State and Transcient Power Distributions for the RELAP Analyses of the 1963 Loss-Of-Flow and Loss-Of-Pressure Tests at br2.

To support the safety analyses required for the conversion of the Belgian Reactor 2 (BR2) from highly-enriched uranium (HEU) to low-enriched uranium (LEU) fuel, the simulation of a number of loss-of-flow tests, with or without loss of pressure, has been undertaken. These tests were performed at BR2 in 1963 and used instrumented fuel assemblies (FAs) with thermocouples (TC) imbedded in the cladding as well as probes to measure the FAs power on the basis of their coolant temperature rise. The availability of experimental data for these tests offers an opportunity to better establish the credibility of the RELAP5-3D model and methodology used in the conversion analysis. In order to support the HEU to LEU conversion safety analyses of the BR2 reactor, RELAP simulations of a number of loss-of-flow/loss-of-pressure tests have been undertaken. Preliminary analyses showed that the conservative power distributions used historically in the BR2 RELAP model resulted in a significant overestimation of the peak cladding temperature during the transient. Therefore, it was concluded that better estimates of the steady-state and decay power distributions were needed to accurately predict the cladding temperatures measured during the tests and establish the credibility of the RELAP model and methodology. The new approach ('best …
Date: May 23, 2011
Creator: Dionne, B. & Tzanos, C. P. (Nuclear Engineering Division)
Object Type: Report
System: The UNT Digital Library