North Korea is making more uranium, probably for its nuclear stockpile

North Korea's propaganda village of Gijungdong is seen from a South Korean military check point of the truce village of Panmunjom in the Demilitarized Zone dividing the two Koreas on Feb. 4, 2015.

New satellite images of North Korea show that it has been increasing its uranium capacity over the last year, which could suggest a corresponding expansion of its nuclear program, according to news reports and a leading non-proliferation expert.

In a Wednesday evening post to 38 North, a web site that monitors North Korea, non-proliferation expert Jeffrey Lewis described what he saw in fresh satellite images of North Korea.

Lewis said it appears that North Korea recently refurbished a key facility associated with the production of uranium ore into yellow cake — a first step towards enriched uranium. The facility in question is near a uranium mine outside Pyongsan, near the border with South Korea.

"This suggests that North Korea intends to mine and mill a significant amount of uranium that could serve as fuel for expanding its nuclear weapons stockpile," Lewis concluded. 

However, as Lewis and the Washington Post point out, the resultant fuel could also be used in light-water reactors that generate electricity, which North Korea may be planning.

As with all reports out about North Korea's nuclear program, this one has not been verified, though Lewis is considered a leading expert.

The analysis also comes days after experts at IHS Jane's, a defense and security firm, said separate satellite images suggested North Korea was operating a second hall of uranium enrichment centrifuges at Yongbyon, according to AFP.

North Korea has previously staged three successful nuclear tests in 2006, 2009 and 2013.