South Korean government scientists have revealed that abnormal levels of radiation were detected near the border with North Korea, days after Pyongyang announced it had created nuclear fusion in mid May. Little serious attention was paid to the North Korean announcement on May 12th that it had made a breakthrough in achieving nuclear fusion for limitless generation of energy.
Now it appears something else nuclear-related may have taken place in the reclusive country, which is believed to have a small number of atomic weapons.
South Korean officials are now acknowledging that two days after Pyongyang's fusion announcement, radioactive xenon, eight times above the normal background level, was detected near the border separating the two Koreas.
But some nuclear scientists are discounting the possibility that a successful attempt at achieving nuclear fusion caused the release of xenon. Professor David Hinde, who is the department head of nuclear physics at The Australian National University, suspects a conventional fission reaction is a more likely explanation.
"It would have to be man-generated unless one came up with some very unusual alternative scenario. The lifetime of those radioactive xenon isotopes, they're not terribly long. So it could not be anything that came naturally, I would say," said Hinde. "Heavy xenon isotopes could be a signature of a fission device of some kind."
Xenon, which is colorless and odorless, occurs naturally in very tiny levels in the atmosphere, but is also, along with another radioactive noble gas, krypton, an atmospheric signature of a nuclear test.
The level of the gas detected by the South Korean monitoring stations, scientists say, should be no cause for alarm.
No explanation is being given as to why South Korea held off announcing the detection of the radioactive gas for more than a month. South Korea is playing down speculation of a North Korean nuclear weapons test, saying no seismic activity was detected that could have originated in North Korea in mid-May.
Pyongyang conducted nuclear tests in 2006 and last year. The explosions prompted widespread condemnation internationally and resulted in U.N. sanctions against North Korea.