[2025 Audit] Navy Chief Says "Building Nuclear-Powered Submarine Will Take Over 10 Years"

Further Discussions with the U.S. Needed for Construction at Philly Shipyard

Navy Chief of Staff Kang Donggil stated that it is expected to take more than 10 years to build the South Korean military's first nuclear-powered submarine.

During a comprehensive audit by the National Defense Committee at the National Assembly on this day, Assemblyman Yoo Yongwon of the People Power Party asked whether it would be possible to change the propulsion system of the Jangbogo-III Batch-III submarine, which the military is planning to build, to a nuclear-powered system. Kang responded, "The start date has not been decided," adding that it would take more than 10 years to complete the project.

He further explained, "If a decision is made, it will take around 10 years, so even if a decision is reached, completion (of construction) would be expected in the mid-2030s."

The government is currently building and operating the 3,600-ton Jangbogo-III Batch-II submarine. The Jangbogo-III Batch-III is reportedly being developed with a displacement increased to over 5,000 tons, which is the typical size for a nuclear-powered submarine. For this reason, there is speculation that this submarine is highly likely to become South Korea's first nuclear-powered submarine.

On the previous day, President Donald Trump announced on the social media platform Truth Social, following a Korea-U.S. summit with President Lee Jaemyung, that he had approved the construction of South Korea's nuclear-powered submarine and that it would be built at the Philadelphia Naval Shipyard (Philly Shipyard) in the United States.

Minister of National Defense Ahn Kyubaek, in response to a question from Jeong Cheongrae, leader of the Democratic Party of Korea, regarding preparations for building a nuclear-powered submarine, explained, "We have already established various conditions necessary to build a nuclear-powered submarine, and the only remaining requirement was fuel. We have now reached a conclusion on that front with the cooperation of the United States."

Regarding the number of nuclear-powered submarines to be introduced, Minister Ahn replied, "We will need to consult with the Navy, but I believe we will need at least four."

Yonhap News Agency

However, Chief of Staff Kang mentioned regarding the construction of a nuclear-powered submarine at the Philly Shipyard, "I believe further discussions between South Korea and the United States are absolutely necessary."

He explained that building a submarine requires a reinforced concrete foundation capable of withstanding thousands of tons and large, concealed construction facilities, but since such facilities do not exist at the Philly Shipyard, additional time will be needed to build new facilities.

Assemblyman Yoo also agreed with Kang's view, stating, "I have personally visited the Philly Shipyard, and there are no facilities for building nuclear-powered submarines. The shipyard only has a couple of large cranes and docks, so I understand that we would manufacture the submarine and small reactors ourselves, while only importing nuclear fuel from the United States."

Assemblyman Yoo then asked Minister of National Defense Ahn, "There is speculation that we might have submarines of the Los Angeles-class (over 6,000 tons displacement) or Virginia-class (over 7,800 tons) built in the United States and brought over. What is the exact situation?" Minister Ahn replied, "This issue only emerged early this morning, so further investigation is needed, and additional discussions between South Korea and the United States are absolutely necessary."