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Feature Articles

  • Mitigating Lightning Hazards

    (pdf file, 413K)

    A new draft document provides guidance for assessing and mitigating the effects of lightning hazards on a Department of Energy (or any other) facility. Written by two Lawrence Livermore engineers, the document combines lightning hazard identification and facility categorization with a new concept, the Lightning Safety System, to help dispel the confusion and mystery surrounding lightning and its effects. The guidance is of particular interest to DOE facilities storing or handling nuclear and high-explosive materials. The concepts presented in the document were used to evaluate the lightning protection systems of the Device Assembly Facility at the Nevada Test Site.

  • Groundwater Modeling: More Cost-Effective Cleanup by Design

    (pdf file, 633K)

    Mathematical modeling allows groundwater remediation planners at Lawrence Livermore National Laboratory to view the soils and pathways in the site's subsurface where contaminated groundwater moves. To improve our picture of the subsurface, we have developed innovative approaches to groundwater modeling and a number of programs that facilitate our use of industry-standard simulation codes. We are applying artificial neural network (ANN) technology to evaluate and optimize "smart" pump-and-treat remediation. We have developed PLANET, a graphical user interface for rapid evaluation of pump-and-treat scenarios, and MapIt, a software tool that can read almost any type of data source and quickly produce input files for a host of simulation codes. Evaluation and data input tasks that used to take weeks and months have been reduced to hours, minutes, or even seconds. These tools and technologies can be used by remediation planners at any site in need of groundwater cleanup. The ability to forecast a groundwater remediation project to its closure allows planners to reliably reduce time and cost as the project progresses.

  • Dual-Band Infrared Computed Tomography: Searching for Hidden Defects

    (pdf file, 440K)

    Federal highway officials estimate that 20% of the country's half-million two-lane bridges are structurally deficient. In April 1996, the Federal Highway Administration began road testing a dual-band infrared computed tomography (DBIR-CT) system developed at Lawrence Livermore that images in three dimensions the defects in the subsurface of bridge decks by using two thermal infrared bands to sense time-dependent temperature differences. Mounted on a converted motor home, the system can scan a 3-meter-wide (10-ft) lane on a bridge and locate defects while traveling at 40 km/h (25 mph). This system enables inspectors to peer beneath a roadbed's surface to find and evaluate hidden trouble spots before they become hazardous. In addition to its applications for the nondestructive inspection and evaluation of bridge decks, DBIR-CT has a number of other applications both inside and outside the Laboratory. Recently, for example, it has been used to detect corrosion within the skins of aircraft and differentiate it from other benign subsurface anomalies such as excess sealant. LLNL has a Cooperative Research and Development Agreement with Bales Scientific Incorporated to commercialize DBIR-CT technology.

    Research Highlight

  • Plating Shop Moves to Finish Off Waste
  • (pdf file, 193K)

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