The industry ministry has found a way to squeeze more life out of aging nuclear reactors even after they reach the mandatory 60-year lifespan limit since the start of operations.

It is set to effectively extend operational periods by excluding periods when plants were shut down for safety inspections by the nation’s nuclear watchdog. This has sometimes taken years.

The ministry also considered lifting the 60-year cap entirely as Prime Minister Fumio Kishida gropes for ways to operate reactors for a longer period.

But the Ministry of Economy, Trade and Industry decided not to, so as to avoid a possible backlash from the public, given the stringent safety regulations enforced by the Nuclear Regulation Authority in the aftermath of the triple meltdown at the Fukushima No. 1 nuclear power plant in March 2011.

The disaster resulted in revisions in the reactor regulation law in 2012 to limit operations of reactors to 40 years in principle as a measure to help ensure the safety of nuclear plants. Prior to the Fukushima disaster, no such regulations existed.

Under the revised law, reactors were also allowed to operate for up to 20 more years as an exception if they are certified as safe by the NRA.

But this extension includes periods when reactors remain offline due to safety inspections by the NRA.

Setting a ceiling on the lifespan of reactors was considered a pillar of safety regulations for a country that experienced one of the world’s most serious nuclear accidents.

The ministry’s latest move followed a call by Kishida in August for a government panel to consider extending the operational life of reactors beyond the current setup.

While sticking to the existing 40-year and extra 20-year rules, the ministry will shift to not count the periods when reactors were shut down due to NRA inspections for restarts and court injunctions against operations.

Some reactors have remained idle for several years due to stalled safety inspections.

The planned change would allow reactors to operate for up to 70 years after they first went into service if they went offline for 10 years during that period.

In addition, clauses governing reactors’ operation periods are expected to be removed from the reactor regulation law, which currently comes under NRA jurisdiction, to the electric utilities industry law, over which the ministry has oversight.

That means the ministry will have more say about the extended operation of old reactors.

Key issues include whether they will contribute to a stable supply of power and decarbonization and whether the approach taken by plant operators to safety issues is appropriate during the process of periodic inspections.

Under the envisioned setup, the NRA would be tasked with checking the deterioration of reactors and buildings housing them when they reach the 30-year mark after going into operation. After that, a periodic check will be conducted within 10 years of the previous one.

Proponents of nuclear power contend that the periods when reactors remain offline can safely be subtracted from the extension rules, arguing that the facilities will not suffer any deterioration caused by operations.

But experts point out that reactors and relevant equipment still cannot avoid time-related degradation even when they are offline.

Experts fear the move by the ministry to have more say about extended operations could influence the outcome of safety checks of nuclear facilities. The ministry has long championed nuclear power for the nation’s energy needs.

The Kishida administration is shifting back to more reliance on nuclear power due to global calls for nations to reduce their carbon footprints as well as secure a stable power supply.

In the aftermath of the Fukushima nuclear disaster, pitching a plan to a build a new nuclear plant in Japan remains an enormous challenge, raising the prospect the country will eventually be left with no nuclear plants.

The government intends to slow the pace of nuclear phaseout by extending the reactor operation period.

It also seeks to help the financial standing of utilities to allow them to recoup their investment by giving them more time.

Operators of nuclear plants have been forced to invest huge sums of money to ensure that their facilities are better protected against terrorist threats and natural and other unforeseen disasters after more stringent reactor regulations were enforced in 2013.

Some in Kishida’s Liberal Democratic Party are clamoring for the ceiling on the operational period for reactors to be scrapped entirely.

But the ministry has shied away from doing so as lifting the cap could heighten public anxiety over the safety of nuclear plants.