President Lee Jae-myung listens to a report on the basic plan for nuclear-powered submarine development by Minister of National Defense Ahn Gyu-baek at the 1st Future Defense Strategy Committee held in Jinhae-gu, Changwon-si, Gyeongsangnam-do, on the 26th. [Photo=Yonhap News]

The reason why President Lee Jae-myung's announcement of building a nuclear-powered submarine is suspected to be a security message for the election is not because nuclear submarines themselves are unnecessary. The problem lies in the timing and content.

Three days before the early voting for the June 3rd local elections, on the 26th, the government unveiled the basic plan for the development of a nuclear-powered submarine. It linked North Korea's submarine-based nuclear and missile threats, the underwater kill chain, self-reliant defense, the ROK-US alliance, and the defense industry all at once.

However, the method of fuel procurement and reactor performance, which are the starting points for nuclear submarine design, have not yet been publicly disclosed.

Minister of National Defense Ahn Gyu-baek reported the "Basic Plan for the Development of a Republic of Korea Nuclear-Powered Submarine" at the 1st Future Defense Strategy Committee held in Jinhae, Gyeongsangnam-do, with President Lee in attendance.

The government named this project the "Jangbogo N Project" and set the goal of launching the first vessel in the mid-2030s and achieving operational capability in the late 2030s.

It was announced that low-enriched uranium with an enrichment level below 20% would be used as nuclear fuel, and it would be developed for long-term operation to minimize fuel replacement. It was also explained that it would be developed and built domestically, utilizing Korea's reactor and shipbuilding technology.

The primary justification put forth by the government is the North Korean threat. Minister Ahn stated that a nuclear-powered submarine would be a key asset in responding to North Korea's submarine-based nuclear and missile threats. He explained that it could monitor and track North Korean submarines more stealthily and quickly than diesel submarines, thus contributing to the realization of an underwater kill chain.

President Lee defined the nuclear submarine as a symbol of self-reliant defense to be built "based on the ROK-US alliance." On the surface, it appears to be a long-term security plan. However, given that the President personally attended and brought up this message at the final stage of the election campaign, it is difficult to avoid political interpretations.

The core of a nuclear submarine is not the hull, but the fuel and reactor.

Depending on the enrichment level of uranium and its form and density, the reactor's output, core size, shielding structure, hull layout, refueling cycle, and operational endurance will vary.

The government's statement of "low-enriched uranium below 20%" is close to the non-proliferation standard of not using high-enriched uranium for nuclear weapons. However, this alone does not explain the actual performance of a Korean-type nuclear submarine.

Even with the same low-enriched uranium, the tactical deployment capabilities of a submarine can vary significantly depending on the enrichment level, fuel density, and the extent of long-term operation.

The ROK-US Joint Fact Sheet from last year is important in this regard. The Fact Sheet released by the White House included the US's approval of the construction of a Korean nuclear-powered attack submarine.

However, at the same time, the US stated that it would cooperate closely with Korea to advance the requirements of this shipbuilding project, including the "fuel procurement route." This means that while the US opened the door for building nuclear submarines, it has not publicly finalized the method of nuclear fuel procurement.

Therefore, the government's declaration of "domestic construction" alone is not sufficient.

If we are to speak of self-reliant defense, we must first explain who will supply the fuel, the heart of a nuclear submarine, in what way, and under what legal framework.

The government also explained that it would communicate closely with the US in the process of securing and managing low-enriched uranium and establish a safeguards system with the International Atomic Energy Agency (IAEA).

This indicates that the issue of nuclear submarine fuel is not a matter that can be concluded solely with a declaration of domestic technology, but rather a problem that must be resolved through ROK-US consultation and within the international non-proliferation framework.

A comparison with existing assets is also necessary.

If the government cites the monitoring and tracking of North Korean submarines and the underwater kill chain as justifications, it must explain what is lacking in the Jangbogo-III class submarines that Korea already possesses.

Hanwha Ocean's KSS-III CPS, proposed for the Canadian submarine project, is advertised as being capable of submerging for over three weeks and sailing over 7,000 nautical miles, based on fuel cell AIP and lithium-ion batteries.

It also offers capabilities for operating torpedoes, mines, cruise missiles, ballistic missiles, and a vertical launch system.

The Dosan Ahn Changho, during its recent call in Canada, sailed approximately 15,000 km over about two months, crossing the Pacific Ocean. This demonstrates that Korea's diesel/AIP submarines already possess significant long-range deployment capabilities.

It is clear that nuclear-powered submarines can provide superior long-term submerged endurance and sustained high-speed maneuverability compared to existing assets.

However, if the performance capabilities that the Korean-type nuclear submarine being pursued by the government can achieve based on low-enriched uranium are not disclosed, the explanation of "preparing for North Korean threats" is insufficient.

Ultimately, the questions converge into one.

It is not a question of whether nuclear submarines are needed, but rather what the Korean-type nuclear submarine discussed by the government can do better and by how much compared to existing Jangbogo-III assets.

Its sustained high-speed tracking capability, long-term covert surveillance capability, oceanic deployment capability, or its ability to enhance the real-time nature of the underwater kill chain must be presented.

However, this announcement prioritized the political symbols of "nuclear submarine," "North Korean threat," and "self-reliant defense" over this differentiation.

The timing also fuels suspicion. May 26th, the date of the announcement, was three days before the early voting for the June 3rd local elections.

Early voting is conducted for two days starting five days before the election day. If the President personally attended a meeting in the final stages of the election and mentioned nuclear submarines, North Korean threats, self-reliant defense, and the recovery of wartime operational control all at once, it cannot be viewed solely as a routine defense administration schedule.

Even if it is a long-term defense plan, the manner and timing of its announcement inevitably lead to it being interpreted as election politics.

Nuclear submarines may be necessary. Considering North Korea's SLBM threats and the naval power buildup of neighboring countries, the argument that Korea should enhance its underwater operational capabilities can certainly be raised.

However, the issue of necessity and the issue of the timing of the announcement are different.

If the nuclear submarine card was revealed three days before the early voting, without sufficient explanation of the fuel procurement method, reactor performance, or advantages over existing assets, it is bound to be suspected as a security frame used in the final stages of an election, even while being a defense policy.

Self-reliant defense is a matter of capability, not a slogan.

What is more important than branding a nuclear submarine is how its core—the fuel—will be secured.

The US provided approval for construction. However, the fuel procurement route still remains in the realm of follow-up ROK-US consultations.

If the justification is to counter North Korean threats, the reasons why existing assets are insufficient must be explained. If the justification is self-reliant defense, the dependence on the US for fuel procurement must be explained.

If the government fails to adequately answer these two questions, the announcement of the nuclear submarine will inevitably face criticism for being a security card played in the final stages of an election rather than a completed military technology plan.