Twelve Years Just to Tear Down? Nuclear Decommissioning Takes as Long as Construction [Digging Energy]

Full-Scale Decommissioning Begins for Korea’s First Commercial Nuclear Plant, Kori Unit 1
Dismantling Starts with Non-Controlled Area, Completion Targeted for 2037
Securing Full-Cycle Technology for Nuclear Construction, Operation, and Decommissioning
Potential Entry into the 500 Trillion Won Global Decommissioning Market

Interior view of the turbine room of Gori Unit 1 located in Gijang-gun, Busan. Korea Hydro & Nuclear Power

On the afternoon of March 18, as we entered the turbine building of Kori Unit 1 located in Gijang County, Busan, stickers reading "Unused Equipment Related to Permanent Shutdown" were attached throughout the facility. Kori Unit 1, the nation’s first commercial nuclear power plant, was opened to the media for the first time since the Nuclear Safety and Security Commission approved its decommissioning in June of last year.

Kori Unit 1 began construction in 1972 and started operation in June 1977. By the time it was permanently shut down in June 2017, it had produced enough electricity over 40 years to supply the entire city of Busan for eight years, and now it is set to disappear into history.

The First Commercial Nuclear Power Plant Disappearing into History

Taking the elevator to the third-floor turbine room, scaffolding was set up around the pipes near the turbines and generators, and a sign reading "Installation and Dismantling Work in Progress" was posted.

The turbine room of Kori Unit 1, separated from the turbine room of adjacent Kori Unit 2 by a partition wall, was awaiting full-scale decommissioning. Kwon Ha-uk, head of construction management at Korea Hydro & Nuclear Power, explained, "We plan to start removing asbestos and insulation from this month," adding, "This marks the official start of dismantling work in the non-controlled area."

Previously, in November of last year, Korea Hydro & Nuclear Power signed a contract for dismantling work in the non-controlled area with a consortium led by Doosan Enerbility, which also includes HJ Heavy Industries & Construction and Korea Plant Service & Engineering.

Nuclear power plants generate electricity by spinning turbines with high-temperature, high-pressure steam produced in the reactor. The containment building, housing the reactor, cooling system, steam generator, and spent nuclear fuel, is designated as a radiation-controlled area. The non-controlled area, not exposed to radiation, is where facilities such as turbines and generators for power production are located.

The decommissioning process for Kori Unit 1 will go through several stages: dismantling the non-controlled area, removing spent nuclear fuel, dismantling the radiation-controlled area, processing radioactive waste, and restoring the site. The entire process is expected to be completed by 2037, taking 12 years in total—a period nearly as long as it took to build the plant.

Dismantling Order: Non-Controlled Area Followed by Controlled Area

According to Korea Hydro & Nuclear Power, meticulous preparation is required even before beginning dismantling. To enable the smooth use of various equipment needed for the work, power facilities are established, and a partition wall is installed between the turbine buildings of Units 1 and 2.

At the same time, a dedicated dismantling waste treatment facility is built to safely process waste generated during decommissioning.

The initial stage of dismantling the non-controlled area involves removing the turbine building and yard area facilities. The pipes connected to the turbines and generators within the turbine building are cut sequentially. Then the turbines, generators, and condensers are dismantled according to pre-established procedures. Additionally, equipment inside the yard’s mixed-bed room and some tanks are also dismantled.

For the dismantling of the radiation-controlled area, spent nuclear fuel must first be safely removed. To ensure worker safety, decontamination work is carried out on the systems, machinery, and inside the building to remove residual radioactivity.

Once the preliminary decontamination is complete, the pipes inside the reactor building are cut, packaged as they are, and transported to the dismantling waste facility. Afterwards, large equipment such as steam generators, reactor coolant pumps, and pressurizers inside the reactor building are dismantled and moved to the treatment facility.

At the dismantling waste treatment facility, equipment is cut using remote devices, residual contaminants are removed, and then the equipment is stored in separate containers.

After large equipment is dismantled, cranes and monorails are used to dismantle the internal facilities of the reactor building. The internal structures of the reactor are dismantled first, followed by the removal of the pressure vessel.

For cutting the pressure vessel, equipment such as wire saws and robotic arms are used. The dismantled and cut equipment is placed in packaging containers, and dismantling of general equipment and pipes completes the work in the controlled area.

Once the removal of equipment inside the radiation-controlled area is finished, work moves to the latter stage of dismantling the non-controlled area, which involves demolishing the turbine building as well as above-ground and underground concrete structures.

"Securing Full-Cycle Technology for Nuclear Construction, Operation, and Decommissioning"

After building demolition is completed, residual radioactivity is measured and safety is reviewed before site restoration takes place. Site restoration includes conducting surveys of soil and groundwater contamination, followed by backfilling and landscaping.

Internationally, restored sites have been used as green space, power plant parking lots, or commercial land. Korea Hydro & Nuclear Power stated, "For Kori Unit 1, we plan to determine the use of the restored site by considering the impact on the safe operation of Kori Unit 2, overseas cases, and feedback from local residents."

Although the decommissioning of Kori Unit 1 will take 12 years, it is significant for Korea to secure full-cycle technological capability across nuclear construction, operation, and decommissioning.

The experience gained from Kori Unit 1’s decommissioning can also pave the way for entering the global decommissioning market. The cost of decommissioning a nuclear power plant is estimated to be around 1 trillion won. According to the International Atomic Energy Agency (IAEA), a total of 588 nuclear plants are expected to be permanently shut down by 2050. This is why the nuclear decommissioning market is projected to exceed 500 trillion won.

An official from Korea Hydro & Nuclear Power emphasized, "We have secured more than 90% of the overall decommissioning technology in-house, and we plan to use as much domestic technology as possible for the decommissioning."

This content was produced with the assistance of AI translation services.