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Reactor restarts and energy policy in Japan

Nuclear Monitor Issue: 
Jim Green ‒ Nuclear Monitor editor

A Strategic Policy Committee under Japan's Advisory Committee for Natural Resources and Energy has released a draft national Strategic Energy Plan.1,2 The draft plan is likely to be endorsed by Cabinet in mid-2018, possibly with minor revisions.

The proposed electricity generation mix in 2030 is 22-24% for renewables, 20-22% for nuclear, and 56% for fossil fuels (27% LNG, 26% coal, 3% oil).1 The Strategic Energy Plan approved by Cabinet in 2014 described nuclear power as an "important base-load energy source" but did not specify growth targets.

Nuclear power is again described as an "important base-load energy source" in the latest draft energy plan, and the government will "further intensify efforts" to achieve the 20-22% nuclear target. Those efforts will include activities such as Fukushima reconstruction and restoration, nuclear power safety improvements, the creation of stable business environments, and efforts to resolve nuclear waste issues.1

Regardless of the government's commitment to the 20-22% nuclear target, it will be near impossible to achieve and would represent a six-fold leap from the current state: in 2017, nuclear accounted for just 3.6% of electricity generation.3,4

Achieving the target would require a total of about 30 operating reactors. Former World Nuclear Association executive Steve Kidd noted in March 2018: "Most assessments foresee only 20-25 reactors ever returning, and all forecasts of when, how and where exactly this will happen have so far proved wide of the mark."5

Of the 55 operable reactors before the Fukushima disaster, 16 have been permanently shut down ‒ the six Fukushima Daiichi reactors, the Monju fast breeder, and nine others (Mihama-1 and -2, Ohi-1 and -2, Ikata-1 and -2, Genkai-1, Shimane-1 and Tsuruga-1).6,7

That leaves 39 reactors, of which eight are operating: Kansai's Ohi-3 and -4 (both PWR, 1180 MW) and Takahama-3 and -4 (both PWR, 870 MW); Kyushu's Sendai-1 and -2 (both PWR, 890 MW) and Genkai-3 (PWR, 1180 MW); and Shikoku's Ikata-3 (PWR, 890 MW).8,9

Applications to restart an additional 17 reactors are slowly progressing.10 Most but not all of those 17 reactor restarts will probably proceed in the coming years. The prospects are at best uncertain for the 14 reactors that have not yet begun the slow restart approval process.

Another difficulty for the industry is the aging of the reactor fleet ‒ almost half of the current fleet of reactors are at least 30 years old.3 To get anywhere near the 20-22% target would require reactor lifespan extension approvals (from 40 years to 60 years). Takeo Kikkawa, a Tokyo University of Science academic and member of the Strategic Policy Committee, said the 2030 target would be impossible to achieve unless all remaining reactors are granted lifespan extensions, and that in the absence of lifespan extensions or new reactors Japan will have no operating reactors by 2050.11 Nuclear would account for at most 15% of electricity generation in the coming years if lifespan extensions are blocked.12

Last November, the head of the Nuclear Regulation Authority said that the pace of restarts is unlikely to gain any momentum in years to come.13 The pace of reactor restarts has in fact picked up over the past twelve months … but the number of post-Fukushima permanent shut-downs (16) doubles the number of restarts (8), and shut-downs exceed restarts (9:8) even if excluding the six Fukushima reactors and the Monju fast reactor.

Japan's Institute of Energy Economics predicts that a total of 10 reactors will have restarted by the end of March 2019.14 That prediction is dramatically lower than the Institute's wildly inaccurate prediction in July 2016 when it predicted 19 restarts by the end of March 2018 (the true number was seven).15

New reactors?

The draft proposal does not comment on the option of building new nuclear reactors, although it will be difficult to meet the 2030 target in the absence of new reactors ... and impossible to maintain it in subsequent decades without them. Strategic Policy Committee chair Masahiro Sakane described new build as the "inconvenient truth" from which the government averted its eyes.11 In June 2017, Japan's trade minister said the government is not considering building new nuclear plants and denied a media report claiming otherwise.16

Tentative steps are being taken to secure approval to complete two reactors that were under construction before the Fukushima disaster (Shimane-3 and Ohma-1 a.k.a. Oma-1).17,18 The government does not deem the two reactors as "new or additional" as construction started before the Fukushima disaster.19 That logic was lost on 1,100 citizens who took legal action to prevent the Ohma reactor project going ahead ‒ but their case was rejected in the Hakodate District Court.20,21

Leaving aside the two partially-built reactors, the obstacles to new reactor projects are mind-boggling. The obstacles include public and political opposition12, and the severe financial pressures facing Japan's energy companies. Another obstacle is that the industrial and technological capacity to build new reactors has withered in Japan. There has been only one reactor grid-connection in Japan in the past decade, and only five in the past 21 years.3

Nikkei Asian Review reported in April 2017 (before Toshiba exited the reactor construction business):22

"The three major Japanese reactor makers ‒ Hitachi, Mitsubishi Heavy Industries and Toshiba ‒ are seeking to keep their nuclear power business afloat by generating profit from work intended to boost the safety of existing plants.

"They have no choice because no new reactor has begun operation since the No. 3 unit at the Tomari nuclear plant in Hokkaido, Japan's northernmost island, came onstream in 2009. "We have also stopped our efforts to transfer skills and expertise to younger generations of employees," said a senior executive at a major reactor maker.

"The situation also bodes ill for suppliers of reactor parts. The construction of one reactor requires the involvement of anywhere between 300 and 500 suppliers possessing special technologies. "It is not easy to regain technology once it is lost," warned Juichiro Takada, president of Takada, a Kitakyushu, Fukuoka Prefecture-based company in southwestern Japan that has supplied storage tanks and done piping work for many nuclear plants. The company has not been involved in construction work for any new reactor since the Oma project was suspended."


Japan's reactor manufacturing capabilities might be revived with contracts to build in other countries (and perhaps in Japan in the longer-term). The draft Strategic Energy Plan reiterates the Abe administration's policy of promoting nuclear exports.2

But Japan's nuclear export prospects are shaky at best. Japan Times reported in February 2017 that Japanese firms have attempted "with little success" to sell their technologies to countries as diverse as France, Vietnam, India, Turkey, Hungary, Poland, Slovakia, the Czech Republic and the United Arab Emirates.23 Japan Times further noted that in June 2016 Toshiba said its goal was to win orders for 45 or more overseas reactors by 2030 … but the company has exited the reactor construction business.

Hitachi is seeking extraordinary financial backing from both the Japanese and UK governments before committing to building advanced boiling water reactors in Wales (the Wylfa project).24 Mitsubishi Heavy Industries is slowly progressing plans to build reactors in Turkey but another Japanese company, Itochu Trading House, recently pulled out of the project.24

Pro-nuclear commentator Dan Yurman wrote on May 7:24

"The biggest black eye that Japan has gotten in recent years isn't from cleanup troubles at Fukushima, but from the multi-billion dollar cost overruns at the V C Summer site [in South Carolina] where Toshiba's Westinghouse ran the project into the ground with self-inflicted management failures. Toshiba sold the Westinghouse business unit in February unloading it for $1 billion less than it paid to purchase the firm ten years ago.

"Japan has also been pushed out of an opportunity to provide four full size nuclear reactors to Vietnam. In fairness, that country also cancelled similar plans to acquire four Russian nuclear reactors. The country cancelled all of its plans for nuclear power stations in November 2016. The main reasons were fears about costs and the inability of the government to stand up a nuclear safety agency, a regulatory framework, and capability to oversee a construction project involving eight 1000 MW nuclear reactors.

"Japan needs a "win" to get back in the game, and the Sinop project in Turkey is its best chance to get one. Putting together a workable cost and schedule package that can be sold to investors is a big challenge. The country's future in exporting nuclear energy technologies depends on it."

Tom Corben wrote in The Diplomat last December: "Many of Turkey’s largest earthquakes have occurred uncomfortably close to the Sinop site, and seismic safety assessments conducted by Japanese government-commissioned research firms have produced questionably optimistic results. The European Parliament has already called on Turkey to abandon the construction of another reactor complex at Akkuyu due to the risk of a serious industrial-environmental disasters, and there is arguably a similar risk at Sinop. An accident there would present Tokyo with complex moral and legal questions, and discredit Japanese nuclear technology."25

Corben also noted that Japan's willingness to supply India's nuclear power program is problematic: "Meanwhile, as a non-signatory to the Nuclear Non-Proliferation Treaty, the ambiguous nature of assurances from the Indian government that Japanese technology will not be used to produce nuclear weapons is worrying, as is the lack of legal definition around the circumstances in which Japan may justifiably abandon the deal."25


1. Noriyuki Ishii, 8 May 2018, ' Draft of Revised Strategic Energy Plan Aims for Firm Implementation of 2030 Energy Mix, Eyeing 2050 As Well',

2. Shinichi Sekine and Rintaro Sakurai / Asahi Shimbun, 14 May 2018, '20-22% share of nuclear power at core of updated energy policy',


4. Takashi Tsuji, 20 Oct 2017, 'Japan's aging fleet of reactors spell trouble for energy blueprint',

5. Steve Kidd, 7 March 2018, 'Operating reactors - can they still compete?',

6. World Nuclear Association, 22 Dec 2017, 'Kansai opts to retire older Ohi units',

7. Noriyuki Ishii, 29 March 2018, 'Ikata-2 NPP to Be Decommissioned – Would Not be Profitable Beyond Forty Years',

8. World Nuclear Association, 14 May 2018, 'Eighth Japanese reactor resumes power generation',

9. Japan Atomic Industrial Forum, 28 March 2018, 'Thoughts on the Resumption of Operation at the Ohi-3 and Genkai-3 NPPs',


11. Mari Yamaguchi / Associated Press, 16 May 2018, 'Japan draft plan sets ambitious targets for nuclear energy',

12. Nikkei Asian Review, 9 June 2017, 'Japan may call for more nuclear plants down the road',

13. Greg Peel, 14 Nov 2017, 'Uranium Week: Break Out!',

14. World Nuclear Association, 3 Aug 2017, 'Japan to benefit from reactor restarts, says IEEJ',

15. World Nuclear Association, 28 July 2016, 'Japanese institute sees 19 reactor restarts by March 2018',

16. Reuters, 8 June 2017, 'Japan Minister Denies Government Considering New Nuclear Plants',

17. Asahi Shimbun, 22 May 2018, 'Process begins at Shimane nuclear plant to operate new reactor',

18. World Nuclear Association, 22 May 2018, 'Japanese utility seeks to start up new reactor',

19. Asahi Shimbun, 1 Nov 2014, 'Nuclear operators push to open new plant, extend life of aging reactors',

20. Reuters, 19 March 2018, 'Japan court rejects lawsuit against construction of nuclear plant',

21. World Nuclear Association, 19 March 2018, 'Court rules against bid to halt Ohma construction',

22. Nikkei Asian Review, 10 April 2017, 'Japan's nuclear technology faces extinction',

23. Eric Johnston, 15 Feb 2017, 'Toshiba’s woes weigh heavily on government’s ambition to sell Japan’s nuclear technology',

24. Dan Yurman, 7 May 2018, 'Japan's Plans for Nuclear Exports Hit Speed Bumps',

25. Tom Corben, 22 Dec 2017, 'Japan’s Nuclear Exports: Risky Business',