This week health physics researchers from the nation’s largest nuclear engineering department are teaming up with the largest animal science department to examine how pedestrian radiation portals can be used to identify contamination on cattle following a radiological event. The tests they will be performing are part of a project funded by the National Institute of Food and Agriculture (NIFA) and the US Department of Agriculture (USDA) to fill a technology gap that has become even more crucial in light of the nuclear disaster at the Fukushima Daiichi power plant in Japan.
Cattle production is an 8 billion dollar industry in Texas with the feedlot industry in the state producing approximately 30% of the nation’s beef. The impact of a radiological incident on meat and dairy production-whether from the detonation of a nuclear explosive device or from a nuclear power plant disaster-could prove devastating to the state’s economy if the safety of its number one commodity comes into question. Ensuring the safety of the public’s food chain is the ultimate responsibility of the USDA, and there are currently no comprehensive protocols in place for dealing with livestock radiological detection and decontamination.
Faced with the possibility of having to evaluate and decontaminate millions of head of cattle efficiently in the case of a radiological incident, the USDA has turned to NSSPI researchers Dr. Craig Marianno and Dr. Sunil Chirayath, along with NSSPI graduate students, to develop a portable radiation portal monitor specifically designed to test livestock for radioactive contamination. The project builds on research that led to the development of existing animal portal monitors intended for household pets. The NSSPI team is working with Dr. Andy Herring in the TAMU Department of Animal Science to determine how best to implement radiation monitoring in a real farm or ranch setting.
This week, commercial pedestrian radiation portal monitors are being tested with cows from the TAMU beef facility. Sealed sources are placed in protective cases and attached to the animals using straps intended for bovine field research. The portals are placed on the outside of press chutes as the cattle are allowed to enter and exit. The results of this work will help determine if current portal technology can be extended to screen cattle for contamination.
A final step in this project is to develop a custom portal system that can be used on livestock following a radiological event. The team used the Monte Carlo N-Particle (MCNP) software to develop computer models of a cow and cattle chutes and detectors. They were then able to perform MCNP radiation transport simulations to find the optimal detector configuration for the detector systems and determine the minimum detectable activity for each configuration. The best configurations were then adjusted to account for practical concerns, such as how easily and quickly the livestock can be moved through the portal without compromising the animal’s welfare or the possibility of detecting contamination.
This collaboration across the university is proving particularly fruitful to both disciplines. According to Dr. Marianno, the project’s co-principal investigator, “The MCNP simulation of a cow is the first of its kind. Animal science researchers at TAMU are interested in how they might be able to use this model in other forms of research.”