Hanwha Ocean, a key player in South Korea's maritime defense industry, is continuously investing in the development of cutting-edge submarine technology, enhancing its position in the global market. In particular, nuclear-powered submarine technology is drawing attention as a core capability that will change the landscape of future maritime security, and Hanwha Ocean is accumulating unparalleled technological prowess in this field. We will take a closer look at Hanwha Ocean's submarine technology development status, the possibility of evolving into nuclear-powered submarines, and future prospects in the rapidly changing international situation.
Hanwha Ocean is playing a key role in developing the KSS-III Batch-III, a next-generation Korean submarine, aiming for performance comparable to nuclear-powered submarines. This submarine is designed to be over 4,000 tons, with a high-strength special steel hull to enhance durability. Above all, by introducing a small modular reactor (SMR)-based hybrid propulsion system, it is designed to have operational endurance and low-noise navigation capabilities equivalent to nuclear-powered submarines. In addition, it is expected to be a next-generation submarine that can extremely avoid enemy detection by combining AI-based advanced combat systems, high-performance sonar systems, and stealth acoustic shielding technology.
Recently, Hanwha Ocean proved its technological prowess by successfully launching the 'Jang Yeong-sil', the first vessel of the KSS-III Batch-II. The 3,600-ton Jang Yeong-sil, the third in the world to be equipped with lithium-ion batteries on a submarine, is recognized as a world-class submarine capable of remaining submerged for more than three weeks without nuclear propulsion. Based on these technological achievements, Hanwha Ocean is demonstrating strong competitiveness in large-scale international order battles, such as Canada's 60 trillion won submarine project and Poland's 'Orka Project'. Especially in the case of the Canadian project, Hanwha Ocean is presenting a differentiated approach to contribute to the long-term operational efficiency of the Canadian Navy through a localization strategy of maintenance and improvement rather than local construction.
Hanwha Ocean unveiled 17 types of cutting-edge ships that will lead future maritime power at the '2025 International Maritime Defense Industry Exhibition (MADEX 2025)'. Among them, the future submarine showcased innovative technologies such as an angular stealth hull that minimizes acoustic tracking, unmanned system operation using horizontal launchers, and a rim-driven propeller that aims for no noise. This presented a new standard of 'undetectable silence' in the global submarine market and showed the potential to change the paradigm of the future maritime battlefield. Based on these technologies, Hanwha Ocean plans to actively target the global market through customized design and construction tailored to the needs of the purchasing country.
To respond to North Korea's nuclear weapons and submarine threat, the need to secure nuclear-powered submarines has been continuously raised in South Korea. South Korea is assessed to have secured a significant portion of the core technological base essential for building nuclear-powered submarines, such as small reactor design, high-pressure hull material development, and low-noise propulsion technology. However, international diplomatic constraints, such as the US-Korea 123 Agreement, have acted as major variables, restricting the acquisition of highly enriched uranium and the reprocessing of spent nuclear fuel, which are essential for the development of military nuclear-powered submarines. This diplomatic reality shows that close cooperation with the United States is essential for South Korea's nuclear submarine development.
In October 2025, there was significant progress on South Korea's nuclear submarine construction during the US-Korea summit between President Lee Jae-myung and US President Donald Trump. President Trump announced through social media that he had approved South Korea to build nuclear-powered submarines, and specifically mentioned that it would be built at the Philadelphia shipyard in the United States. This refers to the 'Hanwha Philly Shipyard' acquired by Hanwha Ocean, and it suggests that Hanwha Ocean will play a key role in securing South Korea's nuclear-powered submarines. This decision is expected to be a decisive turning point in strengthening South Korea's maritime defense capabilities by resolving a significant portion of the diplomatic constraints that have constrained South Korea's nuclear submarine development.
Hanwha Ocean is strengthening global cooperation under the vision of 'Technology for Peace'. Recently, it is seeking strategic cooperation with HavocAI, a US company specializing in autonomous navigation software for unmanned maritime systems, and is accelerating the development of AI-based autonomous navigation and remote operation technology. This aims to preempt the future unmanned maritime system market and create synergy. In addition, Hanwha Ocean is building a MRO (maintenance, repair, and overhaul) comprehensive management system (TOMMS) for the integrated management of a ship's total life cycle, providing customer-tailored solutions, and expanding its role as a strategic partner leading innovation in the global defense ecosystem.
A1: Hanwha Ocean is currently developing the KSS-III Batch-III submarine, which applies an SMR-based hybrid propulsion system, aiming for long-term operational endurance and low-noise navigation capabilities similar to nuclear-powered submarines. As South Korea's nuclear submarine construction was approved by the United States at the US-Korea summit in October 2025, Hanwha Ocean is highly likely to proceed with the actual construction of nuclear-powered submarines.
A2: In terms of technology, although it has secured a significant portion of small reactor design and high-pressure hull manufacturing technology, international diplomatic constraints, especially the issue of securing and reprocessing nuclear fuel under the US-Korea 123 Agreement, were the biggest obstacles. However, with the recent approval from the United States, the possibility of resolving these constraints has increased.
A3: Hanwha Ocean is recognized for its world-class technology by building state-of-the-art submarines such as the 'Jang Yeong-sil', which is equipped with both lithium-ion batteries and AIP. Future submarine technologies such as stealth hulls, unmanned system operation, and rim-driven propellers unveiled at MADEX 2025 are setting a new standard in the global market.
A4: Hanwha Ocean is securing nuclear submarine construction capabilities through global partnerships, including strengthening its own technology development capabilities and utilizing the US Hanwha Philly Shipyard and cooperation with US HavocAI. Under the vision of 'Technology for Peace', it is leading innovation in the maritime defense industry through investment in future technologies such as AI and smart manufacturing.
0