In recognition of Japan’s rapidly aging nuclear plants, Kansai Electric Power Co. has begun discussing the possibility of decommissioning the Mihama No. 1 and No. 2 reactors, now more than 40 years old, in Fukui Prefecture.

While Kepco officials insist no decision has been made, scrapping them instead of applying for a two-decade extension could set a precedent for other prefectures where older plants that went online in the 1970s and early 1980s, like the ill-fated Fukushima No. 1 plant, now face more stringent safety regulations, posing huge expenditures for any utility interested in keeping them.

The two Mihama reactors in question went into service in 1970 and 1972 and generate a combined 840,000 kw, a small amount compared with modern atomic units, which can generate over 1 million kw each.

Japan’s maximum operating life span for a reactor stands at 40 years. After that, utilities can apply for a one-time, 20-year extension or commence a decommissioning process that can take up to three decades.

It’s a tough choice, one that effects not only consumers, but also the municipalities hosting the plants and the utilities running them.

Keeping reactors online beyond 40 years is expected to become extremely expensive. In addition to the basic costs of meeting the new safety standards that took effect last year, the places hosting them are sure to place additional demands on utilities and the central government — demands that will require further funding and negotiations that will further delay reactivation.

In the case of the Mihama reactors, though, even if a 20-year extension were granted, it’s unclear whether the cost of running them would be recouped by the time the reactors reach the age of 60.

If not, that means more red ink on Kepco’s bottom line, and pressure on the government to pass off the losses to the end users in the Kansai region.

Time is running out to make a decision. Accordng to the government, any utilities wishing to continue running reactors past the 40-year threshold as of July 2016 will have to undergo an extra inspection, for which applications must be submitted by July 2015.

Utilities that apply will have to calculate the financial and political costs over the next two decades.

If they end up receiving state approval for an extension, they have to hope that the electricity from the reactors will generate enough revenue to cover all of the additional costs, both projected and unforeseen, without significantly denting their bottom line. Otherwise, they will have to start the dismantling process.

Yet decommissioning also involves big money. Utilities estimate that scrapping a single reactor will cost at least ¥50 billion, assuming that all goes as planned.

By 2016, all three of Kepco’s Mihama reactors, as well as two of its four reactors at the Takahama plant, also in Fukui Prefecture, will be over 40 years old. This means Kepco must choose whether to dismantle or try to extend the lives of five of its 11 operating reactors.

On top of that, its No. 1 and No. 2 reactors at the Oi power station in Fukui will reach the 37-year mark in 2016, requiring another decision in the next couple of years.

For its part, the government has said it will provide some form of financial support to the utilities if reactors become subject to decommissioning or fail safety inspections and remain shut down.

“The utilities will decide whether to decommission individual reactors, but the government will support a smooth decommissioning process along with the restart of reactors whose safety has been guaranteed,” new economy, trade and industry minister Yuko Obuchi said earlier this month.

Whatever decision Kepco arrives at, it will have a huge impact on Fukui Prefecture, where all 11 of the utility’s reactors are situated. Since the mid-1970s, Fukui has received around ¥400 billion in nuclear power-related subsidies from the central government.

Of this, about ¥190 billion has gone directly to towns such as Mihama that rely on the money to build roads, bridges, dams and sewage systems as well as community centers and other social welfare facilities.

Officials visiting the host municipalities for regular inspections by the Nuclear Regulation Authority, the industry’s new watchdog, as well as utility personnel, help fill local hotels, inns and restaurants, and support a variety of local service industries.

Concerned about what a future without nuclear subsidies might mean, Fukui Gov. Issei Nishikawa met with Obuchi on Sept. 9, just days after she was appointed industry minister, and asked her for additional funding for a variety of infrastructure projects, as well as a guarantee that atomic-related funding would ensure that reactors are completely decommissioned and removed.

“It’s up to the central government to explain how it will take responsibility for securing a storage facility for the spent fuel from decommissioned reactors, for building a disposal facility for their radioactive waste, for ensuring the physical safety of the area hosting the reactor, and for dealing with the industrial and economic effects of decommissioning,” Nishikawa said.

While Fukui is concerned, others in Kansai who have long worried about the reactors, especially their age, greeted the news of possible decommissioning with relief.

Aileen Mioko Smith of Kyoto-based Green Action, an anti-nuclear group, said tearing down the reactors would set a good precedent but added that it is critical to include local participation in the process.

“Local communities should be given the opportunity to enter the decommissioning business rather than again become subcontractors to huge conglomerates,” she said, referring to the general contractors that built the plants.