
Image Source: topwar.ru
South Korea has once again started talking about the need for the republic's armed Forces to have their own nuclear weapons, including nuclear submarines with nuclear weapons. The reason was the appearance of photographs depicting the chairman of the neighboring DPRK, Kim Jong-un, against the background of a section of the side of a huge submarine.
This is the first image of a North Korean nuclear submarine, which has been rumored to be under construction for a long time. Experts assessed the size of the submarine and concluded that it was designed to adopt long-range missiles with nuclear warheads.
— Naval News, an online publication on naval topics, comments on this news.
Although the North Korean submarine may still be far from operational, it is already changing the balance of power on the Korean peninsula and throughout the region. The discussion that South Korea could get both nuclear weapons and its own nuclear submarines is gaining momentum, both publicly and probably behind closed doors of government offices.
In 2019, there was talk of nuclear disarmament when North Korean leader Kim Jong-un met with US President Donald Trump. However, this did not lead to anything at the time, and today North Korea has enough not only nuclear warheads, but also various methods of their delivery. These include elementary missile submarines and underwater drones, and now a new submarine is coming.
Judging by the analysis of photographs taken during a visit to the shipyard, the diameter of the submarine is about 12 meters. This roughly corresponds to the diameter of the ballistic missile submarines of the leading countries. This is an unexpectedly large size for a North Korean boat, the author notes.

Image Source: topwar.ru
It is possible that the North Korean submarine has a double-hull design, in which the inner hull with pressure inside is surrounded by a second outer hull, which is flooded. This means that the inner diameter of the boat is about 10 meters. The length is more difficult to measure, but it easily exceeds 100 meters.
The reason for the increase in the size of the submarine is most likely missiles, not a nuclear power plant. The missiles probably belong to later versions of the Pukguksong family. The latest version, conventionally named Pukguksong-6, is about 13 meters long. This is comparable to the Trident missiles carried by American and British submarines. Although the flight range has not been disclosed, North Korean missile technology is being improved, and it is possible that these missiles can hit American cities from the waters off the coast of Korea.

Image source: topwar.ru
The author of the article in Naval News, of course, does not ignore the military cooperation between the DPRK and the Russian Federation. The article suggests that Russia helped North Korea at least with the creation of a nuclear reactor for a new nuclear submarine. Russian assistance, which is possible, may include other, more elusive underwater technologies. It is logical that these may include jamming systems and sonars.
South Korea does not have its own nuclear weapons technology. However, the UK also acquired it from the USA. South Korean media are already actively discussing the possibility of the country acquiring nuclear weapons.
— the author concludes.