South Korea Wins ISO Lead Role to Write First Global Nuclear Plant Decommissioning Rules

South Korea secured the right Monday to author the world's first international rulebook for dismantling nuclear power plants, a standards victory that positions Seoul to set the terms of competition in a global decommissioning market worth roughly $10 billion a year and growing.

The Korean Agency for Technology and Standards (KATS), an arm of the Ministry of Trade, Industry and Energy, announced that the International Organization for Standardization (ISO) formally approved South Korea's submission as a New Work Item Proposal under ISO Technical Committee 85, which handles nuclear energy and radiological protection standards. Nine member states — including the United States, China, and Japan — voted in favor. The proposal had been before the committee since June 2023, making this approval the culmination of nearly three years of deliberation.

The approved standard will establish general requirements spanning the full decommissioning lifecycle: from the definition of core terminology to the planning, execution, and oversight of dismantlement. As the project leader, South Korea will steer every stage of the drafting. Member countries began submitting input Tuesday, with a target completion date of December 2027.

What ISO Project Leadership Actually Means

In ISO's standards development process, the approved New Work Item Proposal is the first of five stages. The proposal will advance through Working Draft, Committee Draft, Draft International Standard, and Final Draft International Standard phases before adoption as a full international standard. Each stage opens the draft to comment and revision from all member countries. Holding the project-leader position gives South Korea's delegation the most direct influence over how key technical concepts are defined — definitions that will shape what qualifies as compliant decommissioning practice worldwide.

KATS Director General Kim Dae-ja spelled out the commercial objective directly. "We'll push to lead not just at ISO, but also on de facto standards set by bodies like the American Society of Mechanical Engineers," Kim said, "to back the export competitiveness of Korean nuclear plants."

KATS also announced plans to develop nine additional technical standards covering specific phases of the decommissioning process — including radioactive decontamination of facilities and components, structural demolition, radioactive waste management, and site restoration. Experts from the International Atomic Energy Agency will advise on the project to align the new ISO standard with existing IAEA nuclear safety frameworks.

A Market Being Built Reactor by Reactor

The standards win lands as the pipeline of reactors approaching end-of-life swells. More than 220 commercial, experimental, or prototype reactors have already been retired from operation worldwide, yet only roughly 25 have been fully dismantled to greenfield status, according to the World Nuclear Association. Nearly half of the approximately 423 reactors currently in operation are expected to enter the decommissioning process by 2050, each requiring up to 20 or more years to complete.

Market sizing estimates vary across research firms, but multiple analysts place the nuclear decommissioning services market at approximately $7 to $10 billion annually in 2025, with consensus projections pointing toward $11 to $14 billion by the early 2030s. Europe currently holds the largest regional share, driven by Germany's nuclear phase-out and the United Kingdom's extensive legacy reactor inventory. North America is the next largest market. The Asia-Pacific region is growing rapidly.

For a country that generates roughly 31 percent of its electricity from 26 operational nuclear reactors, South Korea has accumulated hands-on decommissioning experience faster than it originally anticipated. The Nuclear Safety and Security Commission approved the full dismantling of Kori Unit 1 — the country's first commercial reactor, which ceased operation in June 2017 after 40 years of service — in June 2025. Korea Hydro and Nuclear Power began removing radioactive materials from that facility earlier in 2025, with full site clearance targeted for 2037.

The Standards Race Has Commercial Stakes

Setting the ISO standard is not a neutral technical exercise. Companies that help write the rulebook are better positioned to design products and services that meet it, and countries whose regulatory frameworks align with the international standard face fewer barriers when bidding on foreign contracts.

South Korea has explicitly framed its decommissioning ambitions as an export play. The Ministry of Trade, Industry and Energy stated in 2019 that Seoul aimed to claim 10 percent of the world's nuclear decommissioning market by the mid-2030s and become one of the five largest players globally. The country has since invested in dedicated research infrastructure — two facilities, one focused on light-water reactor dismantlement and one on heavy-water reactor technology — and has been acquiring the international certifications needed to compete outside its home market.

The ASME reference in Director General Kim's remarks is significant. American Society of Mechanical Engineers codes govern equipment specifications and testing procedures used inside nuclear plants in the United States and are widely adopted internationally. Influence over both ISO standards and ASME codes would give Korea's industry a two-layer advantage in framing what compliant nuclear work looks like.

Nine More Standards Behind the First

The initial ISO standard is designed as a framework document that will anchor a broader family of technical specifications. KATS has identified nine follow-on standards covering decontamination, demolition techniques, waste classification, and site remediation that it intends to develop under the same project leadership structure. Each technical standard in that family would carry forward the terminological and procedural definitions established in the first document — giving the country that authors the framework document persistent influence over the entire series.

The nine-standard plan has no announced timeline beyond the December 2027 target for the initial framework document, but KATS characterized the effort as a sequential one, with each technical standard building on its predecessor.

South Korea Begins at Home

The decision to seek ISO leadership came as South Korea confronted the reality of decommissioning its own aging reactor fleet. Beyond Kori 1, additional reactors are scheduled for shutdown through the early 2030s, giving Korean engineers and regulators a domestic testing ground for the procedures and technologies they intend to export.

The International Atomic Energy Agency reviewed South Korea's nuclear safety regulatory framework in a mission completed in November 2024. The team — comprising senior regulatory experts from 14 countries — found that South Korea had made substantial progress in building an independent regulatory structure since 2011 and was committed to further strengthening its systems. That international peer endorsement lends external credibility to Seoul's standards-setting bid.

The December 2027 target for the initial standard is ambitious. ISO technical standards at this level of complexity typically take several years to move from New Work Item Proposal through all five stages. South Korea's ability to sustain that timeline will depend on how quickly member-country working groups reach consensus on the most contested definitions — particularly around radioactive waste classification thresholds and site release criteria, which vary significantly across national regulatory systems.