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 …

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 …