GAMMA RAY ATTENUATION OF THE M2/M3 BRADLEY FIGHTING VEHICLE
A Thesis Presented to The Academic Faculty
by
Desirée R. Prince
In Partial Fulfillment Of the Requirements for the Degree Master of Science in Nuclear and Radiological Engineering in the Woodruff School of Mechanical Engineering
Georgia Institute of Technology
May 2018
COPYRIGHT © 2018 BY DESIRÉE R. PRINCE GAMMA RAY ATTENUATION OF THE M2/M3 BRADLEY FIGHTING VEHICLE
Approved by:
Dr. Nolan E. Hertel, Advisor The Woodruff School of Mechanical Engineering Georgia Institute of Technology
Dr. Steven Biegalski The Woodruff School of Mechanical Engineering Georgia Institute of Technology
Dr. Paul A. Charp The Woodruff School of Mechanical Engineering Georgia Institute of Technology
Date Approved: April 23, 2018
To my mom, Tina, and my sister and brother, Talia and Shawn. There simply are not
enough words to say what you mean to me, but in a word, “everything.”
ACKNOWLEDGEMENTS
First and foremost, I want to thank my Lord and Savior, Jesus Christ. Through
Him, all things are possible.
Next, I would like to thank my advisor, Dr. Nolan Hertel, for taking me on as his student. Certainly, his support, guidance, and knowledge have made all the difference. I would also like to thank my committee members, Dr. Steven Biegalski and Dr. Paul
Charp, for their support in working through even the most unusual of circumstances.
I would like to say a special thanks to Dr. C-K Chris Wang and Dr. Farzad
Rahnema for their willigness to answer my questions and provide additional guidance on how to proceed on the project.
Many thanks to Dr. Michael Shannon and his team at the Georgia Tech Research
Institute (GTRI) for allowing me to work on this project, and a debt of gratitute to my fellow students John Stooksbury, Caleigh Samuels, and Chad Burns, whose contributions have been invaluable.
Finally, thanks to Nicholas Antonio. As my colleauge, confidant, and “battle buddy,” his support has been indispensible.
iv TABLE OF CONTENTS
ACKNOWLEDGEMENTS iv
LIST OF TABLES vii
LIST OF FIGURES ix
LIST OF SYMBOLS AND ABBREVIATIONS xi
SUMMARY xiii
CHAPTER 1. Introduction 1
CHAPTER 2. Theory and Background 4 2.1 The Linear Attenuation Coefficient 4 2.2 The M2/M3 BFV 5 2.3 The AN/VDR-2 and the 60Co, 137Cs, and 226Ra Sources 9 2.4 The MCNP Transport Code for Computational Modeling 11
CHAPTER 3. Experimental Methodology and Procedures 13
CHAPTER 4. Experimental Data Analysis and Results 16 4.1 The Net Absorbed Dose Rate 16 4.2 Calculating the Experimental Dose Attenuation Coefficient 25 4.3 Calculating the Analytical Dose Attenuation Coefficient 27 4.4 Improvements to the Experiment Design 32 4.4.1 Detector and Source Selection 32 4.4.2 Procedural Considerations 34 4.4.3 Experiment Design Considerations 36
CHAPTER 5. Computational Methodology and Procedures 40
CHAPTER 6. Computational Data Analysis and Results 43 6.1 The Absorbed Dose Rate 43 6.2 Calculating the Computational Dose Attenuation Coefficient 51 6.3 A Comparison of the Experimental, Analytical, and Computational Dose Attenuation Coefficients 53 6.4 Protection Factor 58 6.5 Improvements to the Model 60 6.6 Detector Response in the Simulated Radiation Field 61
CHAPTER 7. Conclusion 63
APPENDIX A. MCNP Input for the Cobalt-60 Source at Position A2 with the AN/VDR-2 Internally Installed 65
v APPENDIX B. MCNP Source Definitions for Sources Positioned around the M2/M3 BFV 71
APPENDIX C. MCNP Input for the Cobalt-60 Simulated Radiation Field with the AN/VDR-2 Internally Installed 74
APPENDIX D. MCNP Source Definitions for the Simulated Radiation Field 80
APPENDIX E. A Revised Comparison of the Experimental, Analytical, and Computational Dose Attenuation Coefficients 81
REFERENCES 85