Photo/IllutrationAlthough the reactors at the Kashiwazaki-Kariwa nuclear power plant in Niigata Prefecture are all offline, 6,000 or so people work at the complex each day. (Asahi Shimbun file photo)

Electric power companies spent more than 5 trillion yen ($47 billion) to maintain and manage idle reactors, passing on the tab to consumers as “costs for nuclear power generation.”

The expenditures by seven utilities for the five-year period between fiscal 2012 and fiscal 2016 were covered mainly by electricity charges.

Although the companies say they can gain profitability by restarting idle reactors, they have yet to initiate procedures to bring about half of the units back online.

The utilities in question are the Hokkaido, Tohoku, Tokyo, Hokuriku, Chubu and Chugoku electric power companies and Japan Atomic Power Co.

The hidden costs emerged after The Asahi Shimbun scrutinized financial statements of 10 utilities with nuclear reactors.

Of the 10, the Kansai, Kyushu and Shikoku electric power companies have resumed partial reactor operations.

It turned out that the seven utilities spent a combined 5.09 trillion yen on 34 idled nuclear reactors in the five-year period after the 2011 Fukushima nuclear disaster.

The expenditures consisted of personnel and outsourcing expenses for maintenance and management of the reactors; spent nuclear fuel reprocessing, which is not an issue with thermal or hydraulic power generation; financial outlays related to compensation for the triple meltdown at the Fukushima No. 1 nuclear power plant; and depreciation costs concerning the construction of nuclear reactors.

Restarting a single reactor with an output capacity of one gigawatt would translate into a revenue increase of 100 billion yen annually and cover their financial outlays to date, the utilities insist.

The three power companies that have resumed limited reactor operations spent 2.47 trillion yen in the five-year period as costs for nuclear power generation. They have 20 nuclear reactors, of which seven have been restarted, including ones not currently in operation.

Circumstances surrounding nuclear power industry have changed drastically since the Fukushima nuclear disaster.

At that time, there were 54 nuclear reactors operating on a commercial basis in Japan. Fourteen are due to be decommissioned.

Of the remaining 40 reactors, seven have restarted. As for the remaining 33 reactors, utilities have yet to apply to the Nuclear Regulation Authority for screening to restart 15 of them.

That is mainly due to costs the companies would incur to implement safety measures under new standards introduced after the Fukushima disaster and the fact that profitability will decline in the case of aged or small reactors.

Even among reactors that utilities applied to reactivate, the prospects for doing so remain murky due to concerns among local governments or the possibility of active faults running just below the reactor buildings.

(This article was written by Takaoki Yamamoto and Eiji Shimura.)