 South African scientists have implanted radioactive material in the horns of 20 rhinos. Kate Bartlett reports that officials hope the pioneering project will prevent poaching. Beckham's gone nuclear. The rhino, named after the British soccer legend, was among those getting radioisotopes injected into their horns at a reserve in South Africa this week. Scientists from a Johannesburg university say while the animals will be unharmed by the small amount of the material, it could prove a deterrent to poachers.