Efforts to restore North Korea’s main nuclear complex in Yongbyon are expected to take more than a year.

A source familiar with North Korean affairs said Friday that some eight-thousand nuclear fuel rods are needed to reactivate the Yongbyon reactors. The source said it would take more than a year for the communist state to gather and refine the necessary amount of uranium needed to make the fuel rods.

According to the source, the North is currently estimated to have around three to four-thousand nuclear fuel rods, most of which have eroded and are unsuitable for use.

The source added that the time needed to reactivate the Yongbyon complex could be drastically reduced if Pyongyang makes all-out efforts to dig for uranium and restore facilities.