Photos of North Korea's its uranium enrichment facility may show an undeclared site for building nuclear bombs just outside of its capital, analysts said. North Korea for the first time showed images on Friday of the centrifuges that produce fuel for its nuclear bombs, as leader Kim Jong Un visited a uranium enrichment facility and called for more weapons-grade material to boost the arsenal. The photos showed Kim walking between long rows of metal centrifuges, the machines that enrich uranium.