Nuclear subs for Korea

Moon Keun-sik
The author, a retire Navy colonel, is a professor of the Kyonggi University Graduate School of Politics.

The Aukus, a trilateral security pact among Australia, the United States and Britain, has caused huge repercussions. That took place after the U.S announced a plan to help Australia build nuclear-propelled submarines. The U.S. claimed that the plan does not violate the Nuclear Non-proliferation Treaty as it’s not related with helping Australia build a nuclear weapon.

Nuclear-powered submarines come in two types — a “strategic submarine” carrying nuclear weapons and an “attack submarine” designed to monitor and track the enemy and engage in underwater battles. The nuclear-powered submarine (SSN) club has been restricted to six nations — the U.S., UK, China, France, Russia, and India. The countries have strategic submarines capable of launching ballistic missiles with nuclear warheads.

Strategic submarines are tasked with launching a preventive or retaliatory strike against the enemy. Britain under the order of Prime Minister Margret Thatcher deployed five nuclear-powered attack submarines and one diesel-powered submarine to the 1982 Falklands War with Argentina. The nuclear-powered submarines arrived in two weeks at the location of territorial conflict and overwhelmed the Argentinian fleet to lead to a triumph of the British naval power. It took five weeks for the diesel-powered submarine to arrive on the scene. After the sub contributed little to the war, Thatcher decommissioned all diesel subs in Britain.

The biggest difference between the nuclear-powered and the diesel-powered submarines lies in the speed and difficulty in detection. In terms of speed, a nuclear-propelled sub can be compared to a bullet train while a diesel-powered sub would be akin to a traditional locomotive. Also, a nuclear-powered submarine can be likened to a stealth fighter jet whereas a diesel-propelled sub is a semi-stealth fighter jet.

A diesel-powered sub has to surface two to three times a day to recharge its batteries. But a nuclear-powered sub does not have to surface above the water as long as the crew is healthy and food is sufficient.

In 2016, North Korea succeeded in firing an SLBM from a diesel-powered submarine. The country is considered to be working on a nuclear-powered submarine. If North Korea succeeds in developing such a submarine equipped with nuclear warheads, it could pose a fatal threat to South Korea and the United States. At this moment, America and Russia are still trying to trace and monitor the movement of the other’s strategic submarines.

In the Cold War days, a U.S. sub capable of keeping tabs on a Soviet nuclear sub for more than three weeks received a presidential medal. Only a nuclear-powered submarine is capable of such underwater missions.

South Korea should be ready for the imminent threat from SLBM attacks from any North Korean nuclear-powered subs.

South Korea has been studying the possibility of designing and building a nuclear-propelled submarine since the early 2000s. It developed its own technology to build the sub. But it cannot secure the nuclear fuel needed to operate a reactor inside a submarine. Under the nuclear agreement with the U.S., South Korea cannot use the uranium from the U.S. for military purposes.

A reactor South Korea wants to use for a nuclear-powered attack submarine requires uranium with less than 20 percent enrichment, and that level of uranium enrichment cannot make a nuclear weapon.

South Korea has been an exemplary country in operating non-military nuclear power, and the U.S. is well aware that Korea does not have any desire to develop its own nuclear bomb. Yet Washington does not allow Seoul to use U.S. uranium of 20 percent or less enrichment needed for nuclear-powered attack subs. The U.S. must not forget that South Korea is more engaged in deterring North Korea, China and Russia on the front lines than India, Pakistan, and Australia. The U.S. was tolerant of Indian and Pakistani nuclear development. But it has been stricter with South Korea due to the strange hierarchy of allies.

South Korea must push for the development of a nuclear-powered submarine to effectively prepare for the SLBM threat from North Korea. The United States must cooperate with South Korea in line with the alliance and its strategic importance.

Translation by the Korea JoongAng daily staff.