The CTBTO detector and South Korea's Radionuclear Species Management Post suggested that North Korea conducted a nuclear test in 2010. However, it is thought that this was a very low output because it was only a nuclide and was not detected by an earthquake. In addition, high-power nuclear weapons were the mainstream of US nuclear weapons during the Cold War, but now they are shifting to low-power nuclear weapons. This suggests a change in the way nuclear weapons should be, leading to problems that require a review of nuclear material management and security systems.