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Reactor restarts in Japan

Nuclear Monitor Issue: 
Jim Green ‒ Nuclear monitor editor

According to the World Nuclear Association, Japan has 43 'operable' power reactors (they are 'operational' according to the IAEA), 3 under construction, 9 'on order or planned', and 3 'proposed'.1 The numbers suggest that Japan's nuclear industry is finally getting back on its feet after the Fukushima disaster ‒ but nothing could be further from the truth.

Before considering the industry's current problems, a little historical context from the World Nuclear Industry Status Report 2016:2

"[I]t has been 17 years since Japan's nuclear output peaked at 313 TWh in 1998. The noticeably sharp decline during 2002-2003, amounting to a reduction of almost 30%, was due to the temporary shutdown of all 17 of Tokyo Electric Power Company's (TEPCO) reactors ‒ seven at Kashiwazaki Kariwa and six at Fukushima Daiichi and four at Fukushima Daini. The shutdown was following an admission from TEPCO that its staff had deliberately falsified data for inclusion in regulatory safety inspections reports. During 2003, TEPCO managed to resume operations of five of its reactors.

"The further noticeable decline in electrical output in 2007 was the result of the extended shutdown of the seven Kashiwazaki Kariwa reactors, with a total installed capacity of 8 GWe, following the Niigata Chuetsu-oki earthquake in 2007. TEPCO was struggling to restart the Kashiwazaki Kariwa units, when the Fukushima earthquake occurred."

Nuclear power accounted for 29% of electricity generation in Japan in 2010, down from the historic peak of 36% in 1998, and plans were being developed to increase nuclear's share to 50%.3 But all of Japan's reactors were shut down in the aftermath of the Fukushima disaster. Reactors didn't power a single light-bulb from September 2013 to August 2015.

Japan had 55 operable reactors before Fukushima (including the ill-fated Monju fast reactor). In addition to the six reactors at Fukushima Daiichi, the permanent shutdown of another six reactors has been confirmed ‒ all of them smallish (<559 MWe) and all of them aging (grid connections between 1969 and 1977): Kansai Electric's Mihama 1 and 2, Kyushu Electric's Genkai 1, Shikoku's Ikata 1, JAPC's Tsuruga 1, and Chugoku Electric's Shimane 1.

So Japan now has 43 'operable' or 'operational' reactors, and it isn't hard to identify some with little or no prospect of ever restarting, such as the four Fukushima Daini reactors (or Monju for that matter).

Two reactors at Sendai in Kagoshima Prefecture were restarted in August and October 2015. And that's it ‒ only two of Japan's 43 'operable' or 'operational' reactors are actually operating. Moreover an anti-nuclear candidate, Satoshi Mitazono, was elected governor of Kagoshima Prefecture in early July 2016 and he announced that he will seek the shut-down of the two Sendai reactors ‒ he can prevent their restart after they shut down for inspection later this year.4

As of 1 July 2016, 11 utilities had applied to the Nuclear Regulatory Authority (NRA) for safety assessments of a total of 26 reactors, including seven reactors that have completed the assessment process. Apart from whatever hurdles the NRA might put in their way, there are other obstacles: citizen-led lawsuits; local political and public opposition; economic factors, in particular the questionable economics of large investments to upgrade and restart aging reactors; and the impact of electricity deregulation and intensified market competition.2

It's anyone's guess how many reactors might restart, but the process will continue to be drawn out ‒ the only strong candidate for restart this year is the Ikata 3 reactor in Ehime Prefecture.

Energy policy

The government's current energy policy calls for a 22‒24% nuclear share of electricity generation by 2030. That is less than half of the pre-Fukushima plans for future nuclear growth (the 50% target), and considerably lower than the 29% nuclear share in 2010. Currently, nuclear power ‒ the two Sendai reactors ‒ account for less than 1%.

To reach the 20‒22% target would require the operation of around 35 reactors by 2030, which seems highly improbable.5

The use of both fossil fuels and renewables has increased since the Fukushima disaster, and energy efficiency has made the task considerably easier ‒ national power consumption in 2015 was 12% below the 2010 level.2

The World Nuclear Industry Status Report comments on energy politics in Japan:2

"Japanese utilities are insisting on, and the government has granted and reinforced, the right to refuse cheaper renewable power, supposedly due to concerns about grid stability ‒ hardly plausible in view of their far smaller renewable fractions than in several European countries ‒ but apparently to suppress competition. The utilities also continue strenuous efforts to ensure that the imminent liberalization of the monopoly-based, vertically integrated Japanese power system should not actually expose utilities' legacy plants to real competition.

"The ability of existing Japanese nuclear plants, if restarted, to operate competitively against modern renewables (as many in the U.S. and Europe can no longer do) is unclear because nuclear operating costs are not transparent. However, the utilities' almost complete suppression of Japanese wind power suggests they are concerned on this score. And as renewables continue to become cheaper and more ubiquitous, customers will be increasingly tempted by Japan's extremely high electricity prices to make and store their own electricity and to drop off the grid altogether, as is already happening, for example, in Hawaii and Australia."

Safety concerns ‒ the case of Takahama

The restart of the Takahama 3 and 4 reactors in Fukui Prefecture is indicative of the nuclear industry's broader problems.6 Kansai Electric Power Company (KEPCO) first applied to the NRA for permission to restart the reactors in July 2013. In February 2015, the NRA gave its permission for KEPCO to make the required safety upgrades. The restart process was delayed by an injunction imposed by the Fukui District Court in April 2015, but the ruling was overturned in December 2015.

Takahama 3 was restarted in late January 2016, and TEPCO was in the process of resolving technical glitches affecting the start-up of Takahama 4, when the Otsu District Court in neighboring Shiga Prefecture ruled on 9 March 2016 that the reactors must be shut down in response to a petition by 29 citizens. The court found that investigations of active fault lines and other safety issues were not thorough enough, it expressed doubts regarding the plant's ability to withstand a tsunami, and it questioned emergency response and evacuation plans.7,8

Citizens and NGOs also questioned the use of arbitrary figures in KEPCO's safety analysis, and fire protection.6

Nuclear Engineering International reported on 2 February 2016: "While there are plans on paper to evacuate some Fukui residents to Hyogo, Kyoto, and Tokushima prefectures, many municipalities there have no detailed plans for receiving evacuees. Kyoto Governor Keiji Yamada said he did not feel adequate local consent had been obtained, citing concerns about evacuation issues. Shiga Governor Taizo Mikazuki said there was a lack of sufficient disaster planning."9

On July 12, the Otsu District Court rejected KEPCO's appeal and upheld the injunction preventing the operation of Takahama 3 and 4.10 KEPCO plans to appeal the decision to the Osaka High Court.

Meanwhile, KEPCO is considering whether it is worth investing in upgrades required for the restart of the Takahama 1 and 2 reactors. The NRA controversially approved 20-year lifespan extensions for the two reactors (grid connected in 1974 and 1975), but citizens have initiated a lawsuit to keep them shut down.11

Broader safety concerns

While safety and regulatory standards have improved in the aftermath of Fukushima, there are still serious problems. Citizens and NGOs have raised countless concerns12, but criticisms have also come from other quarters. When the NRA recently approved lifespan extensions for two Takahama reactors, a former NRA commissioner broke his silence and said "a sense of crisis" over safety prompted him to go public and urge more attention to earthquake risks. Kunihiko Shimazaki, a commissioner from 2012 to 2014, said: "I cannot stand by without doing anything. We may have another tragedy ..."13

Prof. Yoshioka Hitoshi, a Kyushu University academic who served on the government's 2011–12 Investigation Committee on the Accident at the Fukushima Nuclear Power Stations, said in October 2015:14

"Unfortunately, the new regulatory regime is ... inadequate to ensure the safety of Japan's nuclear power facilities. The first problem is that the new safety standards on which the screening and inspection of facilities are to be based are simply too lax. While it is true that the new rules are based on international standards, the international standards themselves are predicated on the status quo. They have been set so as to be attainable by most of the reactors already in operation. In essence, the NRA made sure that all Japan's existing reactors would be able to meet the new standards with the help of affordable piecemeal modifications – back-fitting, in other words."

An International Atomic Energy Agency (IAEA) review in early 2016 made the following recommendations (among others) regarding the NRA:15

  • To attract competent and experienced staff, and develop competencies relevant to nuclear and radiation safety.
  • To amend relevant legislation with the aim of allowing NRA to improve the effectiveness of its inspections. The NRA inspection programme "needs significant improvement in certain areas. NRA inspectors should be legally allowed to have free access to any site at any time. The decision process for initiating reactive inspections should be shortened."
  • To strengthen the promotion of safety culture including a questioning attitude.
  • To give greater priority to the oversight of the implementation of radiation protection measures.
  • To develop requirements and guidance for emergency preparedness and response in relation to radiation sources.

The IAEA further noted that the NRA's enforcement provisions are inadequate:

"There is no clear written enforcement policy in place at the NRA. There is no documented process in place at NRA for determining the level of sanctions. NRA inspectors have no power to enforce corrective actions if there is an imminent likelihood of safety significant event. They are required to defer to NRA headquarters. ... NRA processes for enforcement are fragmented and some processes are not documented. NRA needs to establish a formal Enforcement Policy that sets forth processes clearly addressing items such as evaluation of the severity level of non-conformances, sanctions for different levels of non-conformances, processes for issuance of Orders, and expected actions of NRA inspectors if significant safety issues develop."


The narrative from government and industry is that safety and regulatory standards in Japan are now adequate ‒ or they soon will be once teething problems with the new regime are sorted out. NRA Chair Shunichi Tanaka claims that Japanese regulatory standards are
"the strictest in the world."16

But Japan's safety and regulatory standards aren't strict. Improvements are ongoing ‒ such as NRA actions in response to the IAEA report, and reports that legislation will be revised to allow unscheduled inspections of nuclear sites.13 But improvements are slow, partial and piecemeal and there are forces pushing in the other direction. An Associated Press report states that nuclear laws will be revised in 2017 but not enacted until 2020.17

Reactor lifespan extensions beyond 40 years were meant to be "limited only to exceptional cases" according to then Prime Minister Yoshihiko Noda, speaking in 2012. Extensions were considered an emergency measure against a possible energy crunch. But lifespan extensions have been approved in the absence of an energy crunch, and more will likely follow.18

If Japan's nuclear history is any guide, already flawed safety and regulatory standards will be weakened over time. Signification elements of Japan's corrupt 'nuclear village' are back in control just a few years after the Fukushima disaster.19 Add to that aging reactors, and utilities facing serious economic stress and intense competition, and there's every reason to be concerned about nuclear safety in Japan.

Tomas Kåberger, Professor of Industrial Energy Policy at Chalmers University of Technology in Sweden, noted in the foreword to the latest edition of the World Nuclear Industry Status Report:2

"A nuclear industry under economic stress may become an even more dangerous industry. Owners do what they can to reduce operating costs to avoid making economic loss. Reduce staff, reduce maintenance, and reduce any monitoring and inspection that may be avoided. While a stated ambition of "safety first" and demands of safety authorities will be heard, the conflict is always there and reduced margins of safety may prove to be mistakes."


1. WNA, 1 July 2016, 'World Nuclear Power Reactors & Uranium Requirements',

2. Mycle Schneider, Antony Froggatt et al., 2016, World Nuclear Industry Status Report 2016, or direct download:

3. METI, June 2010, "The Strategic Energy Plan of Japan - Meeting global challenges and securing energy futures".

4. Will Davis, 13 July 2016, 'Who is qualified to determine nuclear plant safety?',

5. Naoki Asanuma, 17 March 2016, 'Japan's nuclear energy policy remains in disarray after court ruling',

6. 11 Feb 2016, 'Third reactor restart in Japan', Nuclear Monitor #818,

7. Naoki Asanuma, 17 March 2016, 'Japan's nuclear energy policy remains in disarray after court ruling',

8. Eric Johnston, 9 March 2016, 'Court issues surprise injunction to halt Takahama nuclear reactors',

9. Nuclear Engineering International, 2 Feb 2016, 'Japan's Takahama 3 begins power generation',

10. Reuters, 12 July 2016, 'Japan court upholds injunction to halt reactors – Kyodo',

11. CNIC, 31 May 2016, 'Suit filed to prohibit operation of Takahama reactors beyond 40 years',

12. See for example Justin McKeating, 14 Dec, 2015, 'Japan's nuclear watchdog isn't policing its own safety standards',

13. Aaron Sheldrick / Reuters, 1 July 2016, 'As Japan re-embraces nuclear power, safety warnings persist',

14. Yoshioka Hitoshi, 23 Oct 2015, 'Time to Stop Nursing the Nuclear Power Industry',

15. IAEA Department of Nuclear Safety and Security, 2016, "Integrated Regulatory Review Service (IRRS) Mission to Japan",

16. JAIF, 22 April 2015, 'Kansai EP Appeals Court Decision Prohibiting Restarts of Takahama NPPs',

17. Mari Yamaguchi / AP, 25 April 2016, 'Japan to raise nuke safety check competency per IAEA review',

18. Masanobu Higashiyama, 21 June 2016, 'INSIGHT: 40-year safety principle erodes in pro-nuclear lobbying',

19. 19 March 2015, 'Japan's 'nuclear village' reasserting control', Nuclear Monitor #800,