"Radiation Transport Simulation Studies using MCNP for a Cow Phantom to Determine an Optimal Detector Configuration for new Livestock Portal,"
M.S. Thesis, Nuclear Engineering, Texas A&M University, College Station, TX (2012).
A large radiological accident will result in the contamination
of surrounding people, animal, vegetation etc. In such a situation
assessing of the level of contamination becomes necessary to plan
for the decontamination. There are plans existing for evaluating
contamination on people. However, there are limited to no plans to
evaluate animals. It is the responsibility of the United States
Department of Agriculture (USDA) to decontaminate animals. So the
objective of this thesis work was to design a scalable gamma
radiation portal monitor (RPM) which can be used to assess the
level of contamination on large animals like cattle. This work
employed a Monte Carlo N-Particle (MCNP) radiation transport code
for the purpose. A virtual system of cow, radiation source
representing the contamination, cattle chute and different detector
configurations were modeled. NaI scintillation detectors were
modeled for this work. To find the optimal detector size and
configuration, different detector orientations were simulated for
different source positions using the MCNP code. Also simulations
were carried out using different number and size of the detectors.
It was found that using 2" x 4" x 16" detector yielded a minimum
detectable activity (MDA) value of 0.4 microCi for 137Cs
source. See Document
Associated Project(s):Effective Contamination Detection for Livestock Following a Radiological Event