President of State Affairs Kim Jong Un inspects Nuclear Weapons Institute and production base of weapons-grade nuclear materials President of State Affairs Kim Jong Un inspects Nuclear Weapons Institute and production base of weapons-grade nuclear materials President of State Affairs Kim Jong Un inspects Nuclear Weapons Institute and production base of weapons-grade nuclear materials President of State Affairs Kim Jong Un inspects Nuclear Weapons Institute and production base of weapons-grade nuclear materials President of State Affairs Kim Jong Un inspects Nuclear Weapons Institute and production base of weapons-grade nuclear materials