Korea’s state-run energy company has taken the first step in the process of decommissioning the country's first-ever commercial nuclear reactor, which was in operation from 1978 to 2017.

The Korea Hydro and Nuclear Power Company(KHNP) said on Tuesday that it has begun the process of decontaminating the Kori-1 nuclear reactor, which involves removing radioactive materials with chemicals to minimize decommissioning workers' radiation exposure.

As the Nuclear Safety and Security Commission can only authorize the decommissioning of the reactor after the decontamination has been completed, the mandatory technical procedure can be considered the first step in the dismantlement process.

Upon the Commission's approval, spent nuclear fuel will be taken out of the Kori-1 reactor, followed by the dismantlement of its nonradioactive structures and radioactive structures, as well as the restoration of the reactor site.

An official at the state company said while completion of the dismantlement process overseas normally takes seven to eight years following approval, it is difficult to forecast how long it will take for the Kori-1 as the issue of building temporary storage for spent fuel remains unresolved.