Lesson 2/Learning Event 8
LEARNING EVENT 8:
PROCESS SURVEY INFORMATION
Determination of dose-rate contours and key dose-rate locations requires large quantities of dose-rate
information. Once the contours and key dose rates have been determined, the remaining dose-rate
information is no longer required on the radiological situation map. For this reason, worksheet overlays
are prepared for the initial identification and surveillance of each contamination hazard and only the
necessary identification data are transferred to a radiological situation map or contamination overlay.
Radiological contamination overlays indicate the contamination in areas of interest. The overlay is
based on measured dose rates and outlines the known areas of contamination. It attempts to provide
overlays may vary from the simplified type to the detailed type. When time or operational requirements
limit the flow of information in areas not controlled by friendly troops, simplified contamination
overlays may be the only type of radiological contamination overlay available to the commander. When
time and operational limitations are less severe, the detailed contamination overlay is prepared. A
detailed contamination overlay is shown in figure 18 on page 70 and a simplified contamination overlay
is shown in figure 19 on page 71.
Detailed Radiological Contamination Overlay. The detailed contamination overlay defines the limits
of the contamination more precisely than does the simplified overlay and shows dose-rate contours
Simplified Radiological Contamination Overlay. The simplified contamination overlay shows the
general limits of the contamination and the minimum dose-rate information necessary to satisfy
command requirements (figure 19).
Plotting Contamination Data
The radiological situation map shows only the minimum essential information about detected and
identified areas of contamination necessary to allow visual interpretation of the situation. Each
contaminated area is depicted on the map by a pattern of dose-rate contour lines and a few key dose
rates for points, routes, or areas of particular concern. This information is developed by plotting
monitoring and survey dose-rate information which has been corrected to unshielded ground dose rates
at the reference time (normally H + 1) for the particular pattern. All monitoring and survey information
for a contaminated area is eventually plotted as ground dose rates.