Gwangju military airport site tapped for semiconductor cluster as power, water challenges loom

With the government designating the Gwangju military airport site as the location for a Honam region semiconductor mega-cluster, securing land use rights, power and water supply, and streamlining military facility procedures have emerged as the central challenges in building the industrial complex.

According to the government on Tuesday, the Ministry of Climate, Environment and Energy plans to secure 6.3 gigawatts of electricity and 650,000 tons of industrial water per day for the semiconductor industrial complex to be built on the Gwangju military airport site.

President Lee Jae Myung on Monday said power and water issues must be addressed proactively — not after other procedures are completed — and should be treated as a given from the outset, reiterating his push for simultaneous, fast-tracked progress across all fronts.

The centerpiece of the power supply plan is the construction of a 345-kilovolt ultra-high-voltage transmission network anchored by the new Jangseong substation. According to government and agency review documents, the semiconductor complex on the military airport site is set to begin receiving power in 2031, with a plan to secure a total of 6.28 GW in phases by 2034.

To that end, approximately 43 kilometers of 345 kV transmission lines and two new 345 kV substations will be built. In the first phase, 4 GW will be supplied via a line running from the new Jangseong substation to the new Gwangju substation, with a second line from the new Jangseong substation directly to the industrial complex added in a later phase.

The new Jangseong substation will serve as a power hub connecting the Sinan offshore wind farm's 3.2 GW capacity, western-region renewable energy sources and the Hanbit nuclear power plant grid to the Gwangju semiconductor complex.

Climate, Environment and Energy Minister Kim Sung-hwan said on site that pre-planning and administrative procedures that typically take four to five years would be completed within one year — and ideally within six months — so that construction can begin, raising the possibility of cutting the overall process to under three years.

However, finalizing transmission line routes, obtaining substation permits, deciding on underground cabling and securing community consent remain variables that could determine the pace of the project.

Water supply will be secured by redistributing and recycling existing water resources in the Honam region. The government believes it can deliver 650,000 tons of industrial water per day by drawing on five existing dams — Dongbok, Juam, Jangheung, Boseonggang and Naju — without building any new large dams.

Specifically, 300,000 tons per day would come from Dongbok Dam — 50,000 tons from existing surplus capacity and an additional 250,000 tons from raising the dam's height — while 50,000 tons of unused allocated water from Juam Dam and 100,000 tons of surplus from Jangheung Dam would also be tapped.

An additional 100,000 tons of power-generation water from Boseonggang Dam would be converted to industrial use, and 100,000 tons saved by replacing some of Naju Dam's agricultural water with Yeongsan River water would also be redirected to industrial supply.

However, among major rivers nationwide, the Yeongsan and Seomjin rivers have the smallest surplus capacity in multipurpose dams to meet new industrial water demand, and their flow rates during drought conditions are also at minimum levels.

According to drought flow data by river basin submitted to People Power Party lawmaker Kim Wi-sang of the National Assembly's Climate, Energy, Environment and Labor Committee by the Ministry of Climate, Environment and Energy — based on figures as of late December last year — the combined standard drought flow of the Yeongsan and Seomjin rivers, which run through the Honam region, was only about 1.87 million tons per day.

By comparison, the Han River's standard drought flow was 8.11 million tons per day, the Nakdong River's was 5.85 million tons and the Geum River's was 2.8 million tons — all far higher. The standard drought flow refers to the minimum flow in a river during a severe drought expected to occur once every 10 years. This means the Yeongsan and Seomjin rivers carry only about one-quarter of the Han River's flow and one-third of the Nakdong River's flow during dry conditions.

Semiconductor manufacturing requires a stable supply of raw water and an ultrapure water production base, and plans to raise Dongbok Dam, convert Boseonggang Dam's power-generation water and replace Naju Dam's agricultural water all require consultation with local residents, farmers and environmental groups.

The saturation of spent nuclear fuel storage at the Hanbit nuclear power plant in Yeonggwang-gun, South Jeolla Province — a key power source for the complex — has also been flagged as a major obstacle. Current storage facilities are on track to reach full capacity in June 2030, making additional facility construction unavoidable.

As of March this year, the spent nuclear fuel storage rate at Hanbit had exceeded 85 percent. Units 3 and 4 were particularly close to capacity, at 92.7 percent and 91.6 percent respectively. All six Hanbit units will run out of storage space by June 2030, at which point the plant would have to halt operations.

Korea Hydro & Nuclear Power aims to complete new storage facilities by July 2030, pending approval from the High-level Radioactive Waste Management Committee, a building permit from Yeonggwang-gun and licensing from the Nuclear Safety and Security Commission. Industry insiders, however, said the timeline is unlikely to be met given community opposition and the licensing process, likening the situation to "building an apartment without a bathroom."