South Korea’s Nuclear Safety & Security Commission (NSSC) has approved the dismantling unit 1 at the Kori NPP in Busan – the first ever decommissioning approval granted in Korea. The 595 MWe pressurised water reactor at Kori 1 began operations in 1978 and operated for nearly four decades before its permanent shutdown was decided in 2015. It was permanently shut down in June 2017, and Korea Hydro & Nuclear Power (KHNP) applied for decommissioning approval in May 2021.
The NSSC has now said it has “reviewed the application documents, including the final decommissioning plan, based on the results of the safety review by the Korea Institute of Nuclear Safety (KINS) and the preliminary review by the Nuclear Safety Expert Committee, and confirmed that it satisfied the technical standards according to the Nuclear Safety Act”.
NSSC Chairman Choi Won-ho noted: “Considering that Kori unit 1 is the first nuclear power plant decommissioning case in Korea, we conducted a detailed review of all evaluation items. We will closely inspect the decommissioning process to ensure that the public can feel safe even during decommissioning, and we plan to transparently disclose the inspection results.”
KINS reviewed the documentation for three years, from February 2022 to verify whether the contents of the final decommissioning plan and quality assurance plan submitted by KHNP were adequate. A KINS official noted: “We reviewed the adequacy of the decommissioning plan based on the radiological characteristics of the Kori unit 1 facility and site, the appropriateness of the radiation protection plan, and the specificity of the radioactive waste management plan. Since February, when the review was completed, the results have been evaluated by the Nuclear Safety Expert Committee.”
The most contentious issue was whether decommissioning work could proceed next to Kori 2. KHNP gave assurances that the system separation between Kori 1&2 had been completed and that the decommissioning work would not affect the safety of Unit 2. There was also concern about possible accidents during the decommissioning process and whether the expected resulting exposure dose would remain below the dose limits. NSSC and KINS evaluated the expected radiation exposure doses for workers involved in the decommissioning operations and nearby residents for each major decommissioning task, all of which were found to be below the threshold.
KINS and the Nuclear Safety Expert Committee determined that KHNP’s preparations for the Kori 1 decommissioning had been conducted appropriately. KHNP established an organisation specifically for decommissioning work and allocated 108 personnel: 25 in the headquarters Nuclear Facility Management Office, 68 in the Kori 1 decommissioning project office, and 15 in the Central Research Institute’s nuclear facility management group. An NSSC official said KHNP had trained 599 decommissioning personnel from 2014 to 2023 and was “continuously advancing workforce development”.
The total expense for the decommissioning of Kori 1 was evaluated at KRW1,713bn ($1.22bn). The cost for managing the decommissioning project and decommissioning activities accounted for KRW808.8bn, and waste disposal for KRW262.5bn. The disposal cost of used nuclear fuel was considered separately in line with the radioactive waste management law and was excluded from this assessment. KHNP is budgeting decommissioning costs setting aside cash annually. As of the end of 2024, KRW964.7bn had been accumulated.
NSSC, KINS, and KHNP expect that the Kori 1 decommissioning to take approximately 12 years. “While it might slightly decrease or increase during the project, arithmetically it is anticipated to be completed by 2037,” an NSSC official said, adding that it typically takes about 8-12 years for such reactors.
The Kori 1 site is expected to be utilised as an industrial site after decommissioning is complete. According to a NSSC official: “’Due to the presence of other Kori units right next to unit 1, it cannot be opened to the public. I understand that KHNP has plans to repurpose it as an industrial site, including constructing nuclear-related facilities.”
NSSC and KINS expect that the decommissioning of Kori 1 will serve as an opportunity to develop nuclear decommissioning expertise. The domestic nuclear industry believes that by participating in the decommissioning of Kori 1 and building a track record, they can enter the international nuclear decommissioning market. KHNP President Hwang Joo-ho noted: “The dismantling of Kori unit 1 will be a turning point for internalising domestic dismantling technology, nurturing specialised personnel, and creating an industrial ecosystem beyond simply demolishing facilities.”
In preparing, KHNP has secured 58 commercialisation technologies for decommissioning while the Korea Atomic Energy Research Institute (KAERI) has independently developed 38 foundational technologies.
The dismantling project will proceed in stages: dismantling preparation, removal of major facilities, radioactive waste processing, and site restoration. KHNP aims to complete removal of used nuclear fuel by 2031, to begin site restoration in 2035, and to conclude dismantling by 2037.
