A validation study of existing neutronics tools against ZPPR-21 and ZPPR-15 critical experiments. (open access)

A validation study of existing neutronics tools against ZPPR-21 and ZPPR-15 critical experiments.

A study was performed to validate the existing tools for fast reactor neutronics analysis against previous critical experiments. The six benchmark problems for the ZPPR-21 critical experiments phases A through F specified in the Handbook of Evaluated Criticality Safety Benchmark Experiments were analyzed. Analysis was also performed for three loading configurations of the ZPPR-15 Phase A experiments. As-built core models were developed in XYZ geometries using the reactor loading records and drawer master information. Detailed Monte Carlo and deterministic transport calculations were performed, along with various modeling sensitivity analyses. The Monte Carlo simulations were carried out with the VIM code with continuous energy cross sections based on the ENDF/B-V.2 data. For deterministic calculations, region-dependent 230-group cross sections were generated using the ETOE-2/MC-2/SDX code system, again based on the ENDF/B-V.2 data. Plate heterogeneity effects were taken into account by SDX unit cell calculations. Core calculations were performed with the TWODANT discrete ordinate code for the ZPPR-21 benchmarks, and with the DIF3D nodal transport option for the ZPPR-15 experiments. For all six ZPPR-21 configurations where the Pu-239 concentration varies from 0 to 49 w/o and the U-235 concentration accordingly varies from 62 to 0 w/o, the core multiplication factor determined with a …
Date: September 30, 2007
Creator: Yang, W.S. & Kim, S.J. (Nuclear Engineering Division)
Object Type: Report
System: The UNT Digital Library
Solutions for Summer Electric Power Shortages: Demand Response andits Applications in Air Conditioning and Refrigerating Systems (open access)

Solutions for Summer Electric Power Shortages: Demand Response andits Applications in Air Conditioning and Refrigerating Systems

Demand response (DR) is an effective tool which resolves inconsistencies between electric power supply and demand. It further provides a reliable and credible resource that ensures stable and economical operation of the power grid. This paper introduces systematic definitions for DR and demand side management, along with operational differences between these two methods. A classification is provided for DR programs, and various DR strategies are provided for application in air conditioning and refrigerating systems. The reliability of DR is demonstrated through discussion of successful overseas examples. Finally, suggestions as to the implementation of demand response in China are provided.
Date: November 30, 2007
Creator: Han, Junqiao & Piette, Mary Ann
Object Type: Article
System: The UNT Digital Library
Status report on SHARP coupling framework. (open access)

Status report on SHARP coupling framework.

This report presents the software engineering effort under way at ANL towards a comprehensive integrated computational framework (SHARP) for high fidelity simulations of sodium cooled fast reactors. The primary objective of this framework is to provide accurate and flexible analysis tools to nuclear reactor designers by simulating multiphysics phenomena happening in complex reactor geometries. Ideally, the coupling among different physics modules (such as neutronics, thermal-hydraulics, and structural mechanics) needs to be tight to preserve the accuracy achieved in each module. However, fast reactor cores in steady state mode represent a special case where weak coupling between neutronics and thermal-hydraulics is usually adequate. Our framework design allows for both options. Another requirement for SHARP framework has been to implement various coupling algorithms that are parallel and scalable to large scale since nuclear reactor core simulations are among the most memory and computationally intensive, requiring the use of leadership-class petascale platforms. This report details our progress toward achieving these goals. Specifically, we demonstrate coupling independently developed parallel codes in a manner that does not compromise performance or portability, while minimizing the impact on individual developers. This year, our focus has been on developing a lightweight and loosely coupled framework targeted at UNIC …
Date: May 30, 2008
Creator: Caceres, A.; Tautges, T. J.; Lottes, J.; Fischer, P.; Rabiti, C.; Smith, M. A. et al.
Object Type: Report
System: The UNT Digital Library
Status report on fast reactor recycle and impact on geologic disposal. (open access)

Status report on fast reactor recycle and impact on geologic disposal.

The GNEP program envisions continuing the use of light-water reactors (LWRs), with the addition of processing the discharged, or spent, LWR fuel to recover actinide and fission product elements, and then recycling the actinide elements in sodium-cooled fast reactors. Previous work has established the relationship between the processing efficiencies of spent LWR fuel, as represented by spent PWR fuel, and the potential increase in repository utilization for the resulting processing waste. The purpose of this current study is to determine a similar relationship for the waste from processing spent fast reactor fuel, and then to examine the wastes from the combination of LWRs and fast reactors as would be deployed with the GNEP approach.
Date: October 30, 2007
Creator: Bauer, T. H.; Morris, E. E. & Wigeland, R. A.
Object Type: Report
System: The UNT Digital Library
Trip report for field visit to Fayetteville Shale gas wells. (open access)

Trip report for field visit to Fayetteville Shale gas wells.

This report describes a visit to several gas well sites in the Fayetteville Shale on August 9, 2007. I met with George Sheffer, Desoto Field Manager for SEECO, Inc. (a large gas producer in Arkansas). We talked in his Conway, Arkansas, office for an hour and a half about the processes and technologies that SEECO uses. We then drove into the field to some of SEECO's properties to see first-hand what the well sites looked like. In 2006, the U.S. Department of Energy's (DOE's) National Energy Technology Laboratory (NETL) made several funding awards under a program called Low Impact Natural Gas and Oil (LINGO). One of the projects that received an award is 'Probabilistic Risk-Based Decision Support for Oil and Gas Exploration and Production Facilities in Sensitive Ecosystems'. The University of Arkansas at Fayetteville has the lead on the project, and Argonne National Laboratory is a partner. The goal of the project is to develop a Web-based decision support tool that will be used by mid- and small-sized oil and gas companies as well as environmental regulators and other stakeholders to proactively minimize adverse ecosystem impacts associated with the recovery of gas reserves in sensitive areas. The project focuses on …
Date: September 30, 2007
Creator: Veil, J. A. & Division, Environmental Science
Object Type: Report
System: The UNT Digital Library