Regulator approves Ikata 2 decommissioning plan

Wednesday, 7 October 2020

Ikata 2 is a 538 MWe pressurised water reactor that began operating in March 1988. It was taken offline in January 2012 for periodic inspections. Shikoku announced in March 2018 that it did not plan to restart the reactor. It said the cost and scale of modifications required to upgrade the 40-year-old unit to meet the country's revised safety standards made it uneconomical to restart it.

The utility submitted an outline of its plans for decommissioning the unit to the NRA on 10 October, 2018. Shikoku also submitted requests to Ehime prefecture and the municipality of Ikata, as specified under nuclear safety agreements concluded with those authorities.

Following a review, which included a total of seven public meetings, the NRA has today approved the decommissioning plan for Ikata 2.

According to the plan, decommissioning of the unit will take about 40 years and will be carried out in four stages. The first stage, lasting about 10 years, will involve preparing the reactor for dismantling (including the removal of all fuel and surveying radioactive contamination), while the second, lasting 15 years, will be to dismantle peripheral equipment from the reactor and other major equipment. The third stage, taking about eight years, will involve the demolition of the reactor itself, while the fourth stage, taking about seven years, will see the demolition of all remaining buildings and the release of land for other uses.

During the first stage, all fuel is to be removed from the unit. This includes 316 used fuel assemblies that will be sent for reprocessing and 102 fresh fuel assemblies that will be returned to the fuel fabricator.

"In the future, we will obtain the consent of Ikata Town and Ehime Prefecture, based on the safety agreement," Shikoku said.

Shikoku decided in March 2016 to decommission unit 1 of the Ikata plant, also a 538 MWe PWR, which began commercial operation in September 1977. That unit had been taken offline in September 2011 for periodic inspections. Upgrades costing more than JPY170 billion (USD1.5 billion) would have been needed at the unit in order for it to operate beyond 40 years. The NRA approved Shikoku's decommissioning plan for Ikata 1 in June 2017. That plan also sees the unit being decommissioned in four stages over a 40-year period.

The utility said, "As with unit 1, we will steadily proceed with the decommissioning of unit 2 with the highest priority given to ensuring safety."