[ErnstStavroBlofeld]

It has to be a nuclear leak or accident. As far as I know(reading Yonhap and the Chosun Ilbo), that spy satellites has not picked up any activity that is usually associated with a upcoming nuclear test.

[bruinbirdman]

"It has to be a nuclear leak or accident"

"Another possibility--the most disturbing one, actually--is that the North Koreans had been telling the truth when on May 12, just two days before South Korea detected the high levels of xenon, they announced they had created a nuclear fusion reaction, a step necessary to the building of a thermonuclear device. Xenon is released whenever uranium is enriched, such as when it is enriched for the core of a nuclear weapon."

yitbos

[gandalftb]

One would expect detectable amounts of Kr-85 to be present along with Xe-133/135 if it were from a reactor discharge.

A new weapon would have the Dear Leader braying like a mule.

Could have come from Japan’s Monju breeder reactor that was restarted on May 6.