A Chinese professor has claimed that North Korea conducted a “low-yield underground nuclear test” in May 2010, possibly backing a claim by North Korea that it succeeded in carrying out a nuclear fusion reaction at that time.

Wen Lianxing, the professor who leads a research group on earthquakes and physics at the Beijing-based University of Science and Technology of China, said the North’s claimed nuclear test yielded a 2.9-ton blast with a margin of error of 0.8 ton.

The claimed nuclear test was conducted at 9:08 a.m. (local time) on May 12, 2010, Wen said in his research material posted on the university’s website on Nov. 20, this year. The professor said the research was based on his research group’s “new micro-seismic detection methods.”

North Korea conducted three nuclear tests in 2006, 2009 and 2013. Last year’s third nuclear test was believed to have a maximum yield of 9 kilotons, according to South Korean estimates.

On May 12, 2010, North Korea’s state news outlets reported that the impoverished nation had succeeded in creating a nuclear fusion reaction to produce energy, a claim immediately met by skepticism because the North appears to be incapable of carrying out such a test.

Fusion reactions result in a thermonuclear explosion, such as one generated by a hydrogen bomb, which is far more powerful than a fission device. International experts, however, agree that commercial energy creation from fusion is decades away.

In the research material, Wen said his research group, “Using a new micro-seismic detection method, we confirm that North Korea conducted a small-yield underground nuclear explosion at 9:08 a.m. (local time) on May 12, 2010.”

The professor posted a map and coordinates that identify the site of North Korea’s claimed nuclear explosion in 2010.

The research material did not identify the site’s name, but it appears to be close to North Korea’s northeastern county of Kilju, where the country’s Punggye-ri nuclear test site is located, according to the coordinates. (Yonhap)

Wen said the research material, under the title of “Seismological Evidence for a Low-Yield Nuclear Test on 12 May 2010 in North Korea,” was also published by the latest edition of a U.S.

science magazine, “Seismological Research Letters.”

Wen said South Korean and Western media “ignored” North Korea’s reports about a nuclear fusion reaction at that time, but, “This confirmed nuclear test might be related to the nuclear fusion reaction.”

Calls to Wen’s office or the Chinese university were not immediately answered.

For decades, North Korea has pursued a nuclear weapons program based on plutonium produced from spent nuclear fuel. In late 2010, North Korea unveiled its uranium enrichment facility to visiting U.S. nuclear scientists, giving the country a second way to make nuclear bombs.

South Korea’s defense ministry, however, dismissed Wen’s claim.

“(The government) sees a very low chance that North Korea carried out a nuclear test in May 2010,” Kim Min-seok told a regular press briefing. “Any test of such a small scale cannot be regarded as a nuclear test.” (Yonhap)