James Larkin, Founder The Phisotope Project: And this is like putting a huge, very bright light into the horn of a rhino. Obviously, our eyes can't see it, but the 5detectors see this bright light and it can shine through the walls of a container, through the walls of a suitcase. 

CNN Narrator: This method is designed to 6devalue the horns in the eyes of 7poachers and to 8enhance detection of 9illegally traffickedhorns. It also needed to be safe for the rhinos. 

Craig Marianno, Nuclear Engineering Professor Texas A&M University: So the main question would be how much 10radiation can we use to make sure that the animal is safe? And we determined a specific level that we could use that was both safe for the rhino and that could be detected by modern security systems. 

James Larkin: We're giving these rhinos 11the equivalent of about two CT scans a year. So that's the levels of dose that we're planning to give. And my belief is there will be no harm to these animals. 

CNN Narrator: The radiation levels being read are what will determine the effectiveness of a key part of the plan, limiting movement of poached rhino horns across international borders. 

James Larkin: If this alarm goes off, you might find there's rhino horn, there might be lion bone, there might be ivory, because so often there will be other 12contraband as well. And one of the most important partnerships, I think, is the Nuclear Energy Corporation of South Africa. Well, they've helped me develop the 13isotope. Whenever I've spoken to people and said, look, this is what we're doing, can you help? It's like before I've finished asking the question, 14the sleeves have been rolled up and it's, yes, how can we help? 

We're working with animals which are under 15threat of extinction. So you've got to be darn careful that anything you do with these animals ain't going to harm them because the whole idea is to allow them to live, to 16breed. So the children and our grandchildren see these animals in the wild.