[Yang Nak-gyu's Defence Club] Why Is North Korea's Nuclear Warhead Count Only Estimated?

How many nuclear weapons does North Korea possess? While overseas organizations estimate that North Korea has more than 20 nuclear warheads, experts generally agree that it is practically impossible to make an accurate estimate.

[Image source=Yonhap News]

On the 13th, the Stockholm International Peace Research Institute (SIPRI) in Sweden analyzed in its 2023 Yearbook that North Korea possesses 20 nuclear warheads and has enough fissile material (uranium-235 or plutonium-239) to manufacture 45 to 55 warheads. This is the first time the organization has included North Korea in its global nuclear warhead count.

SIPRI explained, "Last year's report estimated the number of nuclear warheads that could be produced based on the amount of fissile material North Korea holds (40 to 50 warheads), but this year, it recorded an estimate of the actual number of completed warheads." It added, "There is no official evidence that North Korea has produced operational nuclear warheads that can be mounted on and launched by intercontinental ballistic missiles (ICBMs), but it is possible that they possess a small number of warheads for medium-range ballistic missiles."

Earlier, the Federation of American Scientists (FAS) also estimated the number of nuclear warheads North Korea possesses to be over 30, an increase from previous estimates, in its 'World Nuclear Forces Status Index.' Last year, FAS estimated North Korea's nuclear warhead count to be between 20 and 30. This seems related to North Korea recently showcasing miniaturized tactical nuclear warheads and demonstrating its nuclear capabilities. FAS compiles its estimates based on U.S. military data and various research institute findings.

Overseas Organizations Estimate North Korea’s Nuclear Warhead Count at ‘More than 20’
South Korean Military Reveals Only Amount of Nuclear Weapon Materials, Not Warhead Count
Experts Say Accurate Assessment Requires Understanding Miniaturization Technology and Material Quantities

The South Korean military has estimated the amount of materials used to make North Korea’s nuclear weapons but has never officially disclosed the number of nuclear weapons North Korea possesses.

In the ‘2022 Defense White Paper’ published this year, the Ministry of National Defense officially assessed that North Korea holds about 70 kg of plutonium necessary for manufacturing nuclear warheads. This is a reassessment from the 50 kg estimate in the 2016?2020 Defense White Papers (published every two years). Considering North Korea’s technological capabilities, the military estimates that one nuclear warhead can be produced with about 6 kg or less of plutonium. If one warhead requires 5 to 6 kg of plutonium, North Korea possessed enough plutonium last year to produce 12 to 14 nuclear warheads.

Baek Seung-hyuk, former head of the Defense Ministry’s Arms Control Verification Division, said, “To estimate North Korea’s nuclear weapon count, it is necessary to accurately understand the level of nuclear miniaturization technology and the quantities of nuclear materials such as plutonium and uranium.”

The Ministry of National Defense also stated in the Defense White Paper, "North Korea has been producing nuclear materials since the 1980s and is currently estimated to possess about 70 kg of plutonium through nuclear reprocessing and a significant amount of highly enriched uranium (HEU) through uranium enrichment programs." Only the quantities of nuclear weapon materials were mentioned.

For North Korea to make nuclear weapons using plutonium, it must operate a reactor. The problem is that this is practically impossible because operating a reactor would easily expose them to the outside world. North Korea’s first and second nuclear tests, conducted on October 9, 2006, and May 25, 2009, respectively, were carried out using plutonium. However, the third nuclear test used uranium.

North Korea prefers uranium because it can use domestically mined uranium and maintain secrecy.

It is known that North Korea has been operating 2,000 centrifuges at the Yongbyon uranium facility since the end of 2010, capable of producing up to 40 kg of HEU annually. If all 2,000 centrifuges are operational, North Korea could produce 40 kg of highly enriched uranium per year. Moreover, North Korea’s uranium deposits are abundant, estimated at 26 million tons, and are known to be of high purity. This means that if North Korea develops nuclear weapons using uranium, the number of nuclear weapons it can possess could increase indefinitely.

Additionally, unlike plutonium, uranium does not emit smoke, odor, or special substances, making it difficult to detect, and the enrichment process is simpler. If North Korea is secretly enriching uranium outside of Yongbyon, the issues of declaration and verification would make North Korean nuclear negotiations much more difficult.

An intelligence agency official said, “Although we internally estimate North Korea’s nuclear weapon count, officially disclosing it would expose our intelligence-gathering capabilities. North Korea currently has the capacity to produce nuclear weapons independently and can increase its arsenal at any time.”

This content was produced with the assistance of AI translation services.