2.  Objective  Hotspot Software  Gaussian Dispersion Equation  Meteorology Effects: Wind and Air Stability  Scenarios  Modeling  Results  Conclusion

3.  The objective of this project was to create a scenario portraying a nuclear terrorist attack using the software HotSpot. This software evaluates and models how a pollutant disperses into the atmosphere depending on certain variables.

4.  The HotSpot program provides approximation of the radiation effects associated with the atmospheric release of radioactive materials.  Short term accidents or releases

5. C = Downwind concentration, µg/m 3 Q = Pollution source emission rate, µg/s u = Average wind speed, m/s σyσy = y direction plume standard deviation, m σzσz = z direction plume standard deviation, m x = Position in the x direction or downwind direction, m y = Position in the y direction, m z = Position in the z direction, m H = Effective stack height, m

7.  Turbulent dispersion causes the pollutant concentrations to disperse away from the mean flow.  What are the categories of air stability? › A = Very Unstable › B = Moderately Unstable › C = Slightly Unstable › D = Neutral › E = Slightly Stable › F = Stable

8.  How do you determine air stability?

9.  What causes changes in wind flow?  Wind is summarized with direction and velocity.  Urban vs. Rural Environments › Urban environments produce more wind friction than rural environments. › Concentration is inversely proportional to wind speed.

10.  There is a terrorist attack outside the stadium of the 2012 Super Bowl releasing Plutonium-238.  Variables: › Wind speed (2 m/s, 12m/s) › Air Stability (Category A and F) › Amount of explosive (Backpack 20 lbs., Car 200 lbs.) http://www.stadiumsofprofootball.com/afc/LucasOilStadium.htm, 2006

11.  Why Plutonium- 238?  Health effects of Plutonium-238  What is MAR? (Materials at Risk) http://www.clarku.edu/departments/marsh/projects/community/plutonium.pdf, 2002 http://news.discovery.com/space/as-nasas-plutonium-supply-dwindles-esa-eyes-nuclear-energy-program.htm, 2010

12.  Backpack Scenario › MAR 2,000 Ci of Plutonium-238 › Urban environment › 2 m/s and 12 m/s wind speed from the South › Air Stability Category A and F › 20 lbs. of explosive  Car Scenario › MAR 2,000 Ci of Plutonium-238 › Urban environment › 2 m/s and 12 m/s wind speed from the South › Air Stability Category A and F › 200 lbs. of explosive

23. ScenarioStability Class Wind Speed (m/s) Lbs of explosive MAR (Curies) Area of 1000 rem isopleths (km 2 ) BackpackA2202,000 0.076 BackpackA12202,000 0.019 BackpackF2202,000 0.14 BackpackF12202,000 0.017 CarA22002,000 0.037 CarA122002,000 0.015 CarF22002,000 0.046 CarF122002,000 0.008

24.  By changing the variables, we were able to model the most devastating scenario. The variables that caused the most destruction were wind speed at 2 m/s in a stable environment and a lower amount of explosive. This evidence supports all of the background information we learned about Air Dispersion before we modeled our scenarios.

25.  Cooper, C. David., and F. C. Alley. "Chapter 20 Atmospheric Dispersion Modeling." Air Pollution Control: a Design Approach. Third ed. Prospect Heights, IL: Waveland, 2002. 607-48. Print.  Burns, Casey. Overview of Plutonium and Its Health Effects (2002): 6-9. Web. 07 July 2011..  Homann, Steven G. HotSpot. Computer software. National Atmospheric Release Advisory Center (NARAC). Vers. 2.07.1. 2 Mar. 2010. Web..  Lucas Oil Stadium. Photograph. Indianapolis. Stadiums of Pro Football. Web. 13 July 2011..  O'Neil, Ian. "As NASA's Plutonium Supply Dwindles, ESA Eyes Nuclear Energy Program : Discovery News." Discovery News: Earth, Space, Tech, Animals, History, Adventure, Human, Autos. Spaceflight Now, 09 July 2010. Web. 07 July 2011..  "Radiation Risk and Realities." United States Environmental Protection Agency. May 2007. Web. 4 July 2011..