Radiation inspectors checking the area around a former nuclear bomb parts factory in South Carolina, USA stumbled on a radioactive wasp nest on 3 July, NBC News reports.

The nest found on a post near tanks containing radioactive wastewater at the Savannah River Site had a radiation level 10 times that allowed by federal regulations, according to NBC News, citing a report by the US Department of Energy.

A watchdog group raised concerns over the report for not indicating how the nest was contaminated with radioactivity and the possibility that the tanks were leaking.

While radioactivity is to be avoided for safety, animal conservationists are resorting to its use to save African rhinoceros from extinction.

Under the plan by South Africa’s University of the Witwatersrand, a safe dose of radioactive isotopes is injected into the horns of rhinos.

Researchers at Witwatersrand’s Radiation and Health Physics Unit conducted tests to confirm that the amount of radioactive material was not harmful to the animals.

The project dubbed Rhisotope hopes to fight the killing by poachers of 500 rhinos every year in South Africa, where the population of the animal is down to 16,000 from half a million at the beginning of the 20th century.

The radiation emitted by the injected isotope is intended to catch rhino horn smugglers and traffickers. The radioactive isotopes, even at low levels, can be picked up by radiation detectors of customs at airports and borders, unmasking poachers and traffickers, NBC News reports, citing James Larkin, chief scientific officer at the Rhisotope Project.

However, the arrest of horn traffickers may not totally stop the killing of rhinos which die once their tusk is removed from their head.