Despite heavy sanctions, international condemnation and pandemic shortages, North Korea has plowed ahead with its nuclear weapons program in recent years. The U.S. and South Korea have warned that the DPRK is ready to conduct its seventh nuclear test at any time, and Seoul’s latest defense white paper estimates North Korea’s enriched plutonium stockpile now stands at 70 kg.

But while Pyongyang’s stockpiles of fissile material have grown, a look back at the history of the country’s nuclear program shows that it has a poor track record of managing the waste created by its Yongbyon nuclear laboratory and Punggyre-ri test site.