Facility Vulnerability with VISAC

Blastwave Viewer

This viewer shows a 2D slice of the facility geometry with the overpressure (in air) due to the blast overlayed on top. The overpressure function behaves roughly as inversely proportional to the square of the distance from the blast point. The minimum and maximum levels for the contours correspond to the smallest component fragility minimum and the largest component fragility maximum in the facility.

Navigation

The viewer contains a single section view of the facility: front, top or side. The bounding box of the view is shown on the left hand side panel, as well as the value of the cut plane that the view is in. For top views, both the absolute height (elevation above sea level) and the relative height (above ground level) are shown. The user can set the extent of the view showing by changing the bounding box parameters, and then pushing the 'Redraw' button. The value of the cut plane can be set by moving the slider bar or typing in the value. Zooming is done with the mouse (press the mouse button at one corner of your desired zoom area, drag to the opposite corner, then release) or using the 'Scene' menu, the 'Camera' option, and then either 'Zoom In' or 'Zoom Out'.

Figure 11. A Mark 82 blast simulation under the control room of a ficticious nuclear power plant.

Standard Features

As the mouse is moved around the image, the status bar below the image shows the coordinates (usually feet), the name of the region, and the material code for the region. For detailed models, the names of critical components and their damage probabilities will also be displayed. For basic models, the building name will be displayed.

The 'File' menu allows the geometry to be exported or the current image to be saved.

• 'Export Geometry' option - writes out the geometry information in a variety of formats, including BRL-CAD, WaveFront and Unreal Tournement.
• 'Save Image as JPEG' - creates a *.jpeg file for the current view.
• 'Copy Image to Clipboard' - copies the current image to the system clipboard, which can then be pasted into other programs, such as MS Word.

BlastWave Viewer Features

The menu 'Scene', option 'Camera', option 'Default View' will set the bounding box and the cut plane to show the center of the blast and the extent of the blast for the selected view.

There are also several menu options under the 'Scene' menu which allow the user to change the view of the plant. These include which view (Top, Front, Side) and what type of render style to use (Filled or Edges).

The user can click on any point in the Blastwave Viewer to see a description of the QuickBlast calculation at that point: the distance from the blast point, the overpressure (in air) and a listing of what the blast would travel through (walls, air, components, etc) to get to that point.

The menu 'Help', option 'Blast Summary' will list the damaged components and their failure probabilities as well as any holes in walls caused by the blast.

Oak Ridge National Laboratory, 2004

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