Tech trials eyed for reaching melted cores

Reactors 5, 6 to be test units for scrapping plant


Tokyo Electric Power Co. plans to permanently idle the two reactors at the Fukushima No. 1 power plant that were unscathed in the 2011 catastrophe and use them as test platforms for ultimately removing the fuel in the three reactors that suffered core meltdowns, Tepco sources said Wednesday.

The decision was reached following a request by Prime Minister Shinzo Abe, who said in September that the utility should scrap reactors 5 and 6 and focus more on cleaning up the disaster.

But instead of dismantling the two units, they will be used as a research facility to develop technologies for achieving the unprecedented task of removing the melted fuel from reactors 1, 2 and 3, a process that will take decades.

Tepco will explain the plan to the prefectural and nearby local governments.

By accepting Abe’s request, the cash-strapped utility is apparently seeking to win further state help for its decontamination costs outside the plant, which one estimate has shown could reach ¥5 trillion. Tepco’s current estimate of the cost to scrap Fukushima No. 1 is around ¥2 trillion.

As new accounting rules regarding decommissioning went into force in October, Tepco is likely to avoid booking a large extraordinary charge in the business year through March due to a shortfall in decommissioning funds.

In the March 11, 2011, mega-quake and tsunami, the plant lost nearly all its power sources and consequently the ability to cool reactors 1, 2 and 3, and the spent fuel pools at reactors 1 through 4.

Rectors 1 through 3 suffered meltdowns and the building housing unit 4, which did not have fuel inside the core because it was under maintenance, was damaged by a hydrogen explosion.

But reactors 5 and 6, which were in “cold shutdown” mode while also under maintenance at the time the crisis hit, also briefly lost power but cold shutdown was re-established because an emergency diesel generator nearby managed to keep pumping coolant water into the units. That generator was situated at a higher level and thus was not knocked out by the tsunami.