A new report out Thursday appears to show that North Korea has a far stronger nuclear-bomb-making capability than previously thought, The Wall Street Journal reports. An analysis by Stanford University’s Center for International Security and Cooperation suggests that Kim Jong Un has the potential to enrich more uranium and other base ingredients for deadly weapons than was previously known. The research group based its findings on satellite imagery analysis of a uranium mining complex in Pyongsan county. Researchers also analyzed deforestation levels to ascertain mining activity. Previous estimates of North Korea’s annual uranium ore output came in at around 30,000 metric tons; the new analysis shows it could actually be as much as 360,000 metric tons.