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Aerial Measuring System (AMS)Baseline Surveys for Emergency Planning
DOE/NV/25946--1536
This work was done by National Security Technologies, LLC, under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy.
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Mission
Caption
Originally established in the 1960s to support the Nuclear Weapons’Testing Program, the AMS mission is to provide a rapid and comprehensive worldwide aerial measurement, analysis, and interpretation capability in response to a nuclear/radiological emergency.
AMS provides a responsive team of individuals whose processes allow for a mission to be conducted and completed with results available within hours.
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AMS History
DATA VAN
CURRENTDATA ANALYSIS
Twin Bonanza, 1970s
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Examples of Previous Surveys
Alan Vogtle Plant – 1988• 120 square miles• Helicopter with 8 4” x 4” x 16” NaI detectors• 200’ altitude / 250’ and 500’ line spacing
Browns Ferry Station – 1985• 37 square miles• Helicopter with 8 4” x 4” x 16” NaI detectors• 150’ altitude / 250’ line spacing
Turkey Point Plant – 1972• 175 square miles• Fixed-wing aircraft with 14 4” x 4” NaI detectors• 500’ altitude / 6080’ line spacing
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AMS Nuclear Power Plant Survey Considerations
• Size and shape of the survey areas are not consistent between NPP sites and are only a fraction of the 10-mile EPZ total area (314 square miles).
• Future legal ramifications and costs of not performing an aerial survey may outweigh the cost of the survey.
• An aerial radiological background survey of the United States NPP sites has not been performed since 1998.
• Historical survey reports and raw data reside at RSL.
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Current Capabilities - Mission Equipment - Aircraft
Beechcraft King Air B-200 AirplanesTwin-engine turbo prop140 knots (236 feet/sec) (survey speed)Detectors – 12 2” x 4” x 16” NaITypical Survey Flight 3 hrsArea Coverage of ~15 square miles/hour
Four-person crew• Pilot and co-pilot• Scientist/Health physicist• Technician/Technologist
Two Bell-412 HelicoptersTwin-Pac turboshaft engine70 knots (120 feet/sec) (survey speed)Detectors – 12 2” x 4” x 16” NaITypical Survey Flight 2.5 hoursArea Coverage of ~4 square miles/hour Ground Support
• Scientist/Health physicist• Data Analyst• Aircraft mechanic
Three-person crew• Pilot and co-pilot• Technician/Technologist
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Parameters Which Effect Gamma Measurements
1. Inverse square attenuation of point source data2. Air mass attenuation3. Cosmic contribution4. Radon contribution5. Natural isotopes potassium, uranium and thorium (KUT) distribution6. Ground surface anomalies (buildings, vegetation, roads, water
features, etc.)7. Aircraft and system contributions (embedded, stabilization sources,
external contamination)
The effects of these parameters must be characterized either individually or collectively by modeling, measurements, or a combination of both techniques.
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Field Quality Assurance Test Line and Water Line
For quality assurance purposes, field measurements similar to gross count characterizations are made.
1.An easily repeated test line is chosen.2.A suitable water line is chosen. If none exists, a “pseudo water” line (3000 ft above the test line) is substituted.3.Before continuing the survey, an altitude profile is flown. Using the multi-altitude data and water (or pseudo water) line data, the test line activity at survey altitude, the area altitude coefficient, and the area nominal background are derived.4.The chosen test line is flown at the beginning and end of each flight. The values are used to normalize all the survey flights to the same nominal area background.
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Baseline Survey DeliverablesData ProductsTerrestrial Gross Counts/Exposure RateMan-Made Gross CountsSpecific Isotope Activity Plot
All Data Products in GIS Format
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Data Processing Techniques and Algorithms
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Data Presentation Options
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Low detector
•High Resolution•Discrete sampling•Slow coverage•Atmospheric attenuation is small
High detector
•Low resolution•Area averaging•Rapid coverage•Significant sensitivity loss•Atmospheric attenuation is large
500 ft1000 ft1750 ft 50 ft200 ft
Altitude Trade-Offs
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Mission CapabilitiesMinimum Detectable Activity (MDA)
Nominal MDA (surface, soil concentration, point)
Isotope Energy (keV)
Ci/m2 pCi/g mCi
Am-241 59.5 0.20 3.03 0.73
Cs-137 661.6 0.06 0.39 0.33Co-60 1332.5 0.02 0.09 0.16Pa-234m 1001 9.19 48.9 51.0U-235 185.7 0.12 1.26 0.49
• 12 NaI (2x4x16)• 150 feet above ground level
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The Value of a Baseline Survey
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The Value of a Baseline Survey
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The Value of a Baseline Survey
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Mapping the Impacts and Proving the Negative
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“Radiological screening of concerned citizens should be stressed as a major psychosocial stress reduction factor, and aerial surveys could greatly help in alleviating this stress. Populated areas around commercial nuclear plants would be prime aerial baseline survey projects.”
Mark Henry, State of Washington Department of Health, Office of Radiation Protection
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QuestionsQuestions
