Download presentation

Presentation is loading. Please wait.

Published bySammy Self Modified over 3 years ago

1
**Modeling the Effects of a Radiological Dispersion Device Detonation**

Tragan Knight and Nathaniel Tidwell Dr. Melanie Sattler, P.E. Dr. Yvette Weatherton, P.E. Roja Haritha Gangupomu

2
**Nathaniel Tidwell Completed first year at North Central Texas College**

Attending University of Texas Arlington as a sophomore Majoring in Mechanical Engineering

3
**Tragan Knight Eastfield College University of Texas at Arlington**

Major: Civil Engineering (Environmental Engineer) Goals: Master (Material in Science) Ph.D.: (Theology) Aspirations: Reevaluate and innovate the recycling process.

4
Objectives Model the effects of a dirty bomb detonation at Cotton Bowl Stadium in Dallas, Texas Use the HotSpot air dispersion model to run simulations Compare different radionuclides, as well as various atmospheric conditions

5
**Radiological Dispersion Devices**

Also known as RDDs, or “dirty bombs” Use conventional explosives to spread radioactive material over an area Although there is concern that terrorist groups may use dirty bombs, so far none have actually been detonated.

6
**Radionuclides Isotopes that undergo radioactive decay**

Several types of radionuclides are used in medicine and industry We used three different radionuclides in our simulations: 241Am, 137Cs, and 60Co This backscatter gauge, used in industry, contains 137Cs.1 1 Nitus Gamma Backscatter Gauge. Digital image. ThermoScientific.com. Thermo Fisher Scientific Inc., n.d. Web. 23 July 2012.

7
**Radiation Three types of radioactive decay Alpha Beta Gamma**

Helium nucleus (alpha particle) is emitted from an atom Most harmful, but least penetrating Beta Electron or positron (beta particle) is emitted Moderate harm, and moderate penetration Gamma Gamma rays are emitted Least harmful, but highly penetrating

8
**Total Effective Dose Equivalent**

Sum of external and internal effective dose equivalents Unit of measure is the Sievert (Sv) or roentgen equivalent in man (rem) for biological tissue 1 Sv = 100 rems

9
**Biological Effects of Radiation**

1 Effect Dose Blood count changes 50 rem Vomiting (threshold) 100 rem Mortality (threshold) 150 rem LD50/60* (with minimal supportive care) 320 – 360 rem LD50/60 (with supportive medical treatment) 480 – 540 rem 100% mortality (with best available treatment) 800 rem * The LD50/60 is that dose at which 50%of the exposed population will die within 60 days. 1"Biological Effects of Ionizing Radiation." Princeton.edu. Trustees of Princeton University, 30 Apr Web. 26 July 2012.

10
**Air Dispersion Modeling**

Often used to predict downwind concentrations of pollutants, especially from smokestacks We used HotSpot to model an RDD detonation, which uses the Gaussian Plume Model. 𝐶= 𝑄 2𝜋𝑢 𝜎 𝑦 𝜎 𝑧 exp −𝑦 𝜎 𝑦 exp − 𝑧−𝐻 𝜎 𝑧 exp − 𝑧+𝐻 𝜎 𝑧 2

11
Plume Model

12
HotSpot Created by National Atmospheric Release Advisory Center (NARAC) A computer program designed to calculate radiation doses Uses the Gaussian Equation Provides numerous amounts of potential radiological dispersal devices scenarios Used for short-term, short-range (up to 10 km) simulations

13
**HotSpot 2.07.2 Relatively simple surroundings data**

Built-in standard terrain information One meteorological condition per run Less sophisticated than other air dispersion models

14
Parameters Variables Radionuclide Stability Class Rainfall 241Am B Rain 137Cs D No Rain 60Co F Mixture 4 radionuclides * 3 stability classes * 2 rainfall conditions = 24 runs

15
**Other Parameters Material-at-Risk 100 grams High Explosives**

100 pounds TNT equivalent Wind Speed 4.8 m/s Wind Direction 180° (from the south) Rainfall Rate 5 mm/hr Terrain city

16
**Running Simulations HotSpot is very user-friendly**

It takes only a couple minutes to input terms and view results

17
Examples of Outputs

18
Results Inputs and Outputs from Hotspot.

19
Results Comparing differences in stability classes with 241Am B D F

20
Results The figures below compare rainout and dry conditions using 60Co and stability class B. No Rain Rain

21
Results Comparing each isotope in dry conditions with stability class B (a) 241Am (b) 137Cs (c) 60Co (d) Mixture A B C D

22
**Conclusions 60 Co generally had the highest TEDE**

137 Cs generally had the lowest TEDE Radiation doses are higher in scenarios with rain Stability Class F had the largest isopleth area of sickness in all scenarios Worst-case scenario is 60Co, stability class F, in rainy conditions

23
Thank You!

Similar presentations

Presentation is loading. Please wait....

OK

Chapter 5: Nuclear Chemistry

Chapter 5: Nuclear Chemistry

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on general knowledge quiz Ppt on waxes are lipids Ppt on distribution transformer monitoring system Ppt on child labour issues in india Ppt on application of trigonometry in different fields Ppt on polynomials in maths lesson Chapter 1 anatomy and physiology ppt on cells Ppt on solid dielectrics wiki Ppt on digital image processing using matlab Ppt on rational numbers for class 8th