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Multi-Scale Assessment of Prediction Uncertainty in Coupled Reactive Transport Models Conducted at the Florida State University

Description: This report summarizes the research activities in the Florida State University for quantifying parametric and model uncertainty in groundwater reactive transport modeling. Mathematical and computational research was conducted to investigate the following five questions: (1) How does uncertainty behave and affect groundwater reactive transport models? (2) What cause the uncertainty in groundwater reactive transport modeling? (3) How to quantify parametric uncertainty of groundwater reactive tran… more
Date: November 9, 2013
Creator: Ye, Ming
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

PDV Uncertainty Estimation & Methods Comparison

Description: Several methods are presented for estimating the rapidly changing instantaneous frequency of a time varying signal that is contaminated by measurement noise. Useful a posteriori error estimates for several methods are verified numerically through Monte Carlo simulation. However, given the sampling rates of modern digitizers, sub-nanosecond variations in velocity are shown to be reliably measurable in most (but not all) cases. Results support the hypothesis that in many PDV regimes of interest, … more
Date: November 1, 2011
Creator: Machorro, E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Improving Thermal Model Prediction Through Statistical Analysis of Irradiation and Post-Irradiation Data from AGR Experiments

Description: As part of the Research and Development program for Next Generation High Temperature Reactors (HTR), a series of irradiation tests, designated as Advanced Gas-cooled Reactor (AGR), have been defined to support development and qualification of fuel design, fabrication process, and fuel performance under normal operation and accident conditions. The AGR tests employ fuel compacts placed in a graphite cylinder shrouded by a steel capsule and instrumented with thermocouples (TC) embedded in graphit… more
Date: October 1, 2012
Creator: Pham, Dr. Binh T.; Hawkes, Grant L. & Einerson, Jeffrey J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Conventional and systemic Risks: Implications for Individual and Societal Governance

Description: The 17th International Conference on Knowledge Management was held in the historic city of Potsdam, Germany. Since the conference was among the first post-pandemic face to face conferences, the overall theme of the 17th edition of the ICKM conference rightly focused on “Knowledge, Uncertainty and Risks: From individual to global scale” at different levels of analysis and agency. This document highlighted one of the local keynote speeches by Prof. Ortwin Renn, scientific director at the Internat… more
Date: June 2022
Creator: Renn, Ortwin
Item Type: Refine your search to only Book
Partner: UNT College of Information
open access

A sampling-based computational strategy for the representation of epistemic uncertainty in model predictions with evidence theory.

Description: Evidence theory provides an alternative to probability theory for the representation of epistemic uncertainty in model predictions that derives from epistemic uncertainty in model inputs, where the descriptor epistemic is used to indicate uncertainty that derives from a lack of knowledge with respect to the appropriate values to use for various inputs to the model. The potential benefit, and hence appeal, of evidence theory is that it allows a less restrictive specification of uncertainty than … more
Date: October 1, 2006
Creator: Johnson, J. D.; Oberkampf, William Louis; Helton, Jon Craig & Storlie, Curtis B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Understanding Risk Under Conditions of Inherent Uncertainty

Description: The 17th International Conference on Knowledge Management was held in the historic city of Potsdam, Germany. Since the conference was among the first post-pandemic face to face conferences, the overall theme of the 17th edition of the ICKM conference rightly focused on “Knowledge, Uncertainty and Risks: From individual to global scale” at different levels of analysis and agency. This document highlighted one of the keynote speeches by Dave Snowden is the founder of one of the five schools of se… more
Date: June 2022
Creator: Snowden, Dave
Item Type: Refine your search to only Book
Partner: UNT College of Information
open access

Effect of Epistemic Uncertainty Modeling Approach on Decision-Making: Example using Equipment Performance Indicator

Description: Quantitative risk assessments are an integral part of risk-informed regulation of current and future nuclear plants in the U.S. The Bayesian approach to uncertainty, in which both stochastic and epistemic uncertainties are represented with precise probability distributions, is the standard approach to modeling uncertainties in such quantitative risk assessments. However, there are long-standing criticisms of the Bayesian approach to epistemic uncertainty from many perspectives, and a number of … more
Date: June 1, 2012
Creator: Kelly, Dana & Youngblood, Robert
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

R7 VU Born-Assessed Demo Plan

Description: This is an initial draft of a born-assessed VU plan for the RELAP7 (R7) code development effort. The plan will continue to evolve based on the growth of code capability. This growth will be reflected as additional testing is identified and done. Later versions of this document will reflect that growth.
Date: February 1, 2010
Creator: Nourgaliev, Robert
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Uncertainty Quantification of Calculated Temperatures for the AGR-1 Experiment

Description: This report documents an effort to quantify the uncertainty of the calculated temperature data for the first Advanced Gas Reactor (AGR-1) fuel irradiation experiment conducted in the INL’s Advanced Test Reactor (ATR) in support of the Next Generation Nuclear Plant (NGNP) R&D program. Recognizing uncertainties inherent in physics and thermal simulations of the AGR-1 test, the results of the numerical simulations can be used in combination with the statistical analysis methods to improve qualific… more
Date: March 1, 2013
Creator: Pham, Binh T.; Einerson, Jeffrey J. & Hawkes, Grant L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Planning For Quality Data

Description: The assurance of data quality can be a complex process requiring careful planning. The planning process described in this paper uses Data Quality Objectives as the foundation. The described process considers three steps: project requirement identification, definition of the information necessary to answer the questions, and data collection and management. Since sufficient levels of documentation are required at all levels, uncertainty analysis, traceability and custody, data maintenance, and da… more
Date: May 1, 2005
Creator: Evans, Robert P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Use of SUSA in Uncertainty and Sensitivity Analysis for INL VHTR Coupled Codes

Description: The need for a defendable and systematic Uncertainty and Sensitivity approach that conforms to the Code Scaling, Applicability, and Uncertainty (CSAU) process, and that could be used for a wide variety of software codes, was defined in 2008.The GRS (Gesellschaft für Anlagen und Reaktorsicherheit) company of Germany has developed one type of CSAU approach that is particularly well suited for legacy coupled core analysis codes, and a trial version of their commercial software product SUSA (Softwa… more
Date: June 1, 2010
Creator: Strydom, Gerhard
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Impact of Uncertainty on Calculations for Recovery from Loss of Offsite Power

Description: Uncertainty, both aleatory and epistemic, can have a significant impact on estimated probabilities of recovering from loss of offsite power within a specified time window, and such probabilities are an input to risk-informed decisions as to the significance of inspection findings in the U.S. Nuclear Regulatory Commission’s Reactor Oversight Process. In particular, the choice of aleatory model for offsite power recovery time can have a significant impact on the estimated nonrecovery probability,… more
Date: June 1, 2010
Creator: Kelly, Dana L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Navier-Stokes Solvers and Generalizations for Reacting Flow Problems

Description: This is an overview of our accomplishments during the final term of this grant (1 September 2008 -- 30 June 2012). These fall mainly into three categories: fast algorithms for linear eigenvalue problems; solution algorithms and modeling methods for partial differential equations with uncertain coefficients; and preconditioning methods and solvers for models of computational fluid dynamics (CFD).
Date: January 27, 2013
Creator: Elman, Howard C
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Benchmarking Exercises To Validate The Updated ELLWF GoldSim Slit Trench Model

Description: The Savannah River National Laboratory (SRNL) results of the 2008 Performance Assessment (PA) (WSRC, 2008) sensitivity/uncertainty analyses conducted for the trenches located in the EArea LowLevel Waste Facility (ELLWF) were subject to review by the United States Department of Energy (U.S. DOE) Low-Level Waste Disposal Facility Federal Review Group (LFRG) (LFRG, 2008). LFRG comments were generally approving of the use of probabilistic modeling in GoldSim to support the quantitative sensitivity … more
Date: November 12, 2013
Creator: Taylor, G. A. & Hiergesell, R. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Summary discussion of the 1996 performance assessment for the Waste Isolation Pilot Plant

Description: The Waste Isolation Pilot Plant (WIPP) is under development by the US Department of Energy (DOE) for the geologic disposal of transuranic waste. The construction of complementary cumulative distribution functions (CCDFs) for total radionuclide release from the WIPP to the accessible environment is described. The resultant CCDFs (1) combine releases due to cuttings and cavings, spallings, direct brine release, and long-term transport in flowing groundwater, (2) fall substantially to the left of … more
Date: May 19, 2000
Creator: HELTON,JON CRAIG; ANDERSON,D. RICHARD; BASABILVAZO,G.; JOW,HONG-NIAN & MARIETTA,MELVIN G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Conceptual structure of the 1996 performance assessment for the Waste Isolation Pilot Plant

Description: The conceptual structure of the 1996 performance assessment (PA) for the Waste Isolation Pilot Plant (WIPP) is described. This structure involves three basic entities (EN1, EN2, EN3): (1) EN1, a probabilistic characterization of the likelihood of different futures occurring at the WIPP site over the next 10,000 yr, (2) EN2, a procedure for estimating the radionuclide releases to the accessible environment associated with each of the possible futures that could occur at the WIPP site over the ne… more
Date: May 18, 2000
Creator: HELTON,JON CRAIG; ANDERSON,D. RICHARD; BASABILVAZO,G.; JOW,HONG-NIAN & MARIETTA,MELVIN G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Characterization of subjective uncertainty in the 1996 performance assessment for the Waste Isolation Pilot Plant

Description: The 1996 performance assessment (PA) for the Waste Isolation Pilot Plant (WIPP) maintains a separation between stochastic (i.e., aleatory) and subjective (i.e., epistemic) uncertainty, with stochastic uncertainty arising from the possible disruptions that could occur at the WIPP over the 10,000 yr regulatory period specified by the US Environmental Protection Agency (40 CFR 191,40 CFR 194) and subjective uncertainty arising from an inability to uniquely characterize many of the inputs required … more
Date: May 18, 2000
Creator: HELTON,JON CRAIG; MARTELL,MARY-ALENA & TIERNEY,MARTIN S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Radionuclide transport in the vicinity of the repository and associated complementary cumulative distribution functions in the 1996 performance assessment for the Waste Isolation Pilot Plant

Description: The following topics related to radionuclide transport in the vicinity of the repository in the 1996 performance assessment for the Waste Isolation Pilot Plant are presented (1) mathematical description of models, (2) uncertainty and sensitivity analysis results arising from subjective (i.e., epistemic) uncertainty for individual releases, (3) construction of complementary cumulative distribution functions (CCDFs) arising from stochastic (i.e., aleatory) uncertainty, and (4) uncertainty and sen… more
Date: May 22, 2000
Creator: Stockman, Christine T.; Garner, J. W.; Helton, Jon Craig; Johnson, Jay Dean; Shinta, A. & Smith, L. N.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

New Method and Reporting of Uncertainty in LBNL National Energy Modeling System Runs

Description: This report describes LBNL's approach for assessing uncertainty in any National Energy Modeling System (NEMS)-related analysis. Based on years of experience using LBNL-NEMS for various analyses, LBNL developed an alternative approach that aims to provide a simple yet comprehensive perspective of how the results behave under a given set of what we believe to be some of the issues important to large-scale energy modeling. This project has established a standard set of eight sensitivity cases that… more
Date: October 1, 2002
Creator: Gumerman, Etan Z.; LaCommare, Kristina Hamachi & Marnay, Chris
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Uncertainty Evaluation in Large-scale Dynamical Systems: Theory and Applications

Description: Significant research efforts have been devoted to large-scale dynamical systems, with the aim of understanding their complicated behaviors and managing their responses in real-time. One pivotal technological obstacle in this process is the existence of uncertainty. Although many of these large-scale dynamical systems function well in the design stage, they may easily fail when operating in realistic environment, where environmental uncertainties modulate system dynamics and complicate real-time… more
Date: December 2014
Creator: Zhou, Yi (Software engineer)
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Incorporating uncertainty in RADTRAN 6.0 input files.

Description: Uncertainty may be introduced into RADTRAN analyses by distributing input parameters. The MELCOR Uncertainty Engine (Gauntt and Erickson, 2004) has been adapted for use in RADTRAN to determine the parameter shape and minimum and maximum of the distribution, to sample on the distribution, and to create an appropriate RADTRAN batch file. Coupling input parameters is not possible in this initial application. It is recommended that the analyst be very familiar with RADTRAN and able to edit or creat… more
Date: February 1, 2010
Creator: Dennis, Matthew L.; Weiner, Ruth F. & Heames, Terence John (Alion Science and Technology)
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Characterization of stochastic uncertainty in the 1996 performance assessment for the Waste Isolation Pilot Plant

Description: The 1996 performance assessment (PA) for the Waste Isolation Pilot Plant (WIPP) maintains a separation between stochastic (i.e., aleatory) and subjective (i.e., epistemic) uncertainty, with stochastic uncertainty arising from the possible disruptions that could occur at the WIPP over the 10,000 yr regulatory period specified by the US Environmental Protection Agency (40 CFR 191, 40 CFR 194) and subjective uncertainty arising from an inability to uniquely characterize many of the inputs required… more
Date: May 19, 2000
Creator: Helton, Jon Craig; Davis, Freddie J. & Johnson, J. D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Direct releases to the surface and associated complementary cumulative distribution functions in the 1996 performance assessments for the Waste Isolation Pilot Plant: Direct brine release

Description: The following topics related to the treatment of direct brine releases to the surface environment in the 1996 performance assessment for the Waste Isolation Pilot Plant (WIPP) are presented (1) mathematical description of models, (2) uncertainty and sensitivity analysis results arising from subjective (i.e., epistemic) uncertainty for individual releases, (3) construction of complementary cumulative distribution functions (CCDFs) arising from stochastic (i.e., aleatory) uncertainty, and (4) unc… more
Date: May 19, 2000
Creator: Stoelzel, D. M.; O'Brien, D. G.; Garner, J. W.; Helton, Jon Craig; Johnson, J. D. & Scott, L. N.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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