Share

Nuclear Power in Japan

(Updated 25 April 2015)

  • Japan needs to import about 84% of its energy requirements.
  • Its first commercial nuclear power reactor began operating in mid-1966, and nuclear energy has been a national strategic priority since 1973. This came under review following the 2011 Fukushima accident but has been confirmed.
  • The country's 50+ main reactors have provided some 30% of the country's electricity and this was expected to increase to at least 40% by 2017. The prospect now is for at least half of this, from a depleted fleet.
  • Currently 43 reactors are operable and potentially able to restart, and 24 of these are in the process of restart approvals.

Despite being the only country to have suffered the devastating effects of nuclear weapons in wartime, with over 100,000 deaths, Japan embraced the peaceful use of nuclear technology to provide a substantial portion of its electricity. However, following the tsunami which killed 19,000 people and which triggered the Fukushima nuclear accident (which killed no-one), public sentiment shifted markedly so that there were wide public protests calling for nuclear power to be abandoned. The balance between this populist sentiment and the continuation of reliable and affordable electricity supplies is being worked out politically.

Japan's energy situation and international dependence

Japan’s shortage of minerals and energy was a powerful influence on its politics and history in the 20th century. Today it depends on imports for over 90% of its primary energy needs. As it recovered from World War II and rapidly expanded its industrial base it was dependent on fossil fuel imports, particularly oil from the Middle East (oil fuelled 66% of the electricity in 1974). This geographical and commodity vulnerability became critical due to the oil shock in 1973. At this time, Japan already had a growing nuclear industry, with five operating reactors. Re-evaluation of domestic energy policy resulted in diversification and in particular, a major nuclear construction program. A high priority was given to reducing the country's dependence on oil imports. A closed fuel cycle was adopted to gain maximum benefit from imported uranium.

Nuclear power has been expected to play an even bigger role in Japan's future. In the context of the Ministry of Economy, Trade and Industry (METI) Cool Earth 50 energy innovative technology plan in 2008, the Japan Atomic Energy Agency (JAEA) modelled a 54% reduction in CO2 emissions (from 2000 levels) by 2050 leading on to a 90% reduction by 2100. This would lead to nuclear energy contributing about 60% of primary energy in 2100 (compared with 10% in 2008), 10% from renewables (from 5%) and 30% fossil fuels (from 85%). This would mean that nuclear contributed 51% of the emission reduction: 38% from power generation and 13% from hydrogen production and process heat.

In June 2010 METI resolved to increase energy self-sufficiency to 70% by 2030, for both energy security and CO2 emission reduction. It envisaged deepening strategic relationships with energy-producing countries. Nuclear power would play a big part in implementing the plan, and new reactors would be required as well as achieving 90% capacity factor across all plants.

However, following the Fukushima accident, in October 2011 the government sought to greatly reduce the role of nuclear power. This appears to have been a significant factor in them losing office in 2012 elections (see later section). The new government in 2014 adopted the 4th Basic (or Strategic) Energy Plan, with 20-year perspective and declaring that nuclear energy is a key base-load power source and would continue to be utilized safely to achieve stable and affordable energy supply and to combat global warming.

Early in 2011, nuclear energy accounted for almost 30% of the country's total electricity production (29% in 2009), from 47.5 GWe of capacity (net) to March 2011, and 44.6 GWe (net) from then. There were plans to increase this to 41% by 2017, and 50% by 2030.

IEA figures indicate that in 2013 Japan generated 1059 TWh gross, 338 TWh from coal, 408 TWh from gas (up from 300 TWh in 2010), 9 TWh from nuclear (cf 288 TWh in 2010), 161 TWh from oil (up from 94 TWh in 2010), and 84 TWh from hydro. The country’s nuclear capacity was progressively shut following the March 2011 Fukushima accident. Renewables contribution in 2013 was small: solar 10 TWh, wind 5 TWh, geothermal 2.6 TWh, biomass & waste 41 TWh. Final consumption in 2010 was about 1000 billion kWh, or about 7870 kWh per capita. This dropped to 923 TWh, or 7200 kWh/capita in 2012.

Capacity (IEA figures) at end of 2012 was 295 GWe, this being 46 GWe nuclear, 45 GWe hydro, 36 GWe coal, 47 GWe gas, 41 GWe oil, 16 GWe oil or coal, 50.6 GWe autoproducers’ ‘combustible fuels’, 6.6 GWe solar, 2.5 GWe wind and 0.5 GWe geothermal. In response to nuclear difficulties, coal capacity is planned to increase 21% to 47 GWe by early 2020s.

In April 2015 the government announced that it wanted base-load sources to return to providing 60% of the power by 2030, with about one-third of this being nuclear. Analysis by the Research Institute of Innovative Technology for the Earth estimated that energy costs would then be reduced by JPY 2.4 trillion (USD 20.0 billion) per year compared with the present 40% base-load scenario (renewables being 30%). At the same time, it was reported that 43 coal-fired power projects were planned or under construction, totalling 21.2 GWe and expected to emit 127 million tonnes of CO2 per year.

According to a 2011 government report generation costs per kWh were JPY 9 for nuclear, JPY 10 for wind and JPY 30 for solar.

The electricity market is due to be deregulated in April 2016, with legal separation in April 2020 between generation, transmission, and distribution. As the first step towards this, the Organization for Cross-Regional Coordination of Transmission Operators (OCCTO) was set up in April 2015 to function as a national transmission system operator (TSO). All power companies are required to join OCCTO. It will ensure greater interconnection among present utility networks, and increase the frequency converter capacity across the 50-60 Hz east-west divide to 3 GWe by 2021. OCCTO is expected to invest about JPY 300 billion.

In February 2015 the prime minister said that 80% of Japan’s oil and 20% of its natural gas came from the Persian Gulf through the Strait of Hormuz.

Other energy information for Japan can be found at http://www.eia.gov/countries/cab.cfm?fips=JA

Development of nuclear program & policy 1950 to 2005

Japan started its nuclear research program in 1954, with ¥230 million being budgeted for nuclear energy. The Atomic Energy Basic Law, which strictly limits the use of nuclear technology to peaceful purposes, was passed in 1955. The law promoted three principles – democratic methods, independent management, and transparency – are the basis of nuclear research activities, as well as promoting international co-operation. Inauguration of the Atomic Energy Commission (AEC) in 1956 promoted nuclear power development and utilisation. Several other nuclear energy-related organisations were also established in 1956 under this law: the Nuclear Safety Commission (NSC), the Science & Technology Agency; Japan Atomic Energy Research Institute (JAERI) and the Atomic Fuel Corporation (renamed PNC in 1967 – see below).

The first reactor to produce electricity in Japan was a prototype boiling water reactor: the Japan Power Demonstration Reactor (JPDR) which ran from 1963 to 1976 and provided a large amount of information for later commercial reactors. It also later provided the test bed for reactor decommissioning.

Japan imported its first commercial nuclear power reactor from the UK, Tokai 1 – a 160 MWe gas-cooled (Magnox) reactor built by GEC. It began operating in July 1966 and continued until March 1998.

After this unit was completed, only light water reactors (LWRs) utilising enriched uranium – either boiling water reactors (BWRs) or pressurised water reactors (PWRs) – have been constructed. In 1970, the first three such reactors were completed and began commercial operation. There followed a period in which Japanese utilities purchased designs from US vendors and built them with the co-operation of Japanese companies, who would then receive a licence to build similar plants in Japan. Companies such as Hitachi Co Ltd, Toshiba Co Ltd and Mitsubishi Heavy Industry Co Ltd developed the capacity to design and construct LWRs by themselves. By the end of the 1970s the Japanese industry had largely established its own domestic nuclear power production capacity and today it exports to other east Asian countries and is involved in the development of new reactor designs likely to be used in Europe.

Due to reliability problems with the earliest reactors they required long maintenance outages, with the average capacity factor averaging 46% over 1975-77 (by 2001, the average capacity factor had reached 79%). In 1975, the LWR Improvement & Standardisation Program was launched by the Ministry of International Trade and Industry (MITI) and the nuclear power industry. This aimed, by 1985, to standardise LWR designs in three phases. In phases 1 and 2, the existing BWR and PWR designs were to be modified to improve their operation and maintenance. The third phase of the program involved increasing the reactor size to 1300-1400 MWe and making significant changes to the designs. These were to be the Advanced BWR (ABWR) and the Advanced PWR (APWR).

A major research and fuel cycle establishment through to the late 1990s was the Power Reactor and Nuclear Fuel Development Corporation, better known as PNC. Its activities ranged very widely, from uranium exploration in Australia to disposal of high-level wastes. After two accidents and PNC's unsatisfactory response to them the government in 1998 reconstituted PNC as the leaner Japan Nuclear Cycle Development Institute (JNC), whose brief was to focus on fast breeder reactor development, reprocessing high-burnup fuel, mixed-oxide (MOX) fuel fabrication and high-level waste disposal.

A merger of JNC and JAERI in 2005 created the Japan Atomic Energy Agency (JAEA) under the Ministry of Education, Culture, Sports, Science & Technology (MEXT). JAEA is now a major integrated nuclear R&D organization.

A peculiarity of Japan's electricity grids is that on the main island, Honshu, the northeastern half including Tokyo is 50 Hz, served by Tepco (and Tohoku), the southwestern half including Nagoya, Kyoto and Osaka is 60 Hz, served by Chubu (with Kansai & Hokuriku), and there is only 1.2 GWe of frequency converters connecting them. (Japc has plants in both areas, which are separated by the Itoigawa River.) This frequency difference arises from original equipment coming from Germany and USA respectively. The interconnection is being increased to 2.1 GWe by 2020, funded by the utilities, and METI plans a further increase to 3 GWe in same time frame. Early in 2015 METI established OCCTO as a new body to balance electricity supply and demand in wide areas across Japan (see above).

More recent energy policy 2002-2011: Focus on nuclear

Japan's energy policy has been driven by considerations of energy security and the need to minimise dependence on current imports. The main elements regarding nuclear power were:

  • continue to have nuclear power as a major element of electricity production.
  • recycle uranium and plutonium from used fuel, initially in LWRs, and have reprocessing domestically.
  • steadily develop fast breeder reactors in order to improve uranium utilisation dramatically.
  • promote nuclear energy to the public, emphasising safety and non-proliferation.

In March 2002 the Japanese government announced that it would rely heavily on nuclear energy to achieve greenhouse gas emission reduction goals set by the Kyoto Protocol. A 10-year energy plan, submitted in July 2001 to the Minister of Economy Trade & Industry (METI), was endorsed by cabinet. It called for an increase in nuclear power generation by about 30 percent (13,000 MWe), with the expectation that utilities would have up to 12 new nuclear plants operating by 2011. In fact only five (5358 MWe net) came on line in that decade.

In June 2002, a new Energy Policy Law set out the basic principles of energy security and stable supply, giving greater authority to the government in establishing the energy infrastructure for economic growth. It also promoted greater efficiency in consumption, a further move away from dependence on fossil fuels, and market liberalisation.*

* In November 2002, the Japanese government announced that it would introduce a tax on coal for the first time, alongside those on oil, gas and LPG in METI's special energy account, to give a total net tax increase of some JPY 10 billion from October 2003. At the same time METI would reduce its power-source development tax, including that applying to nuclear generation, by 15.7% – amounting to JPY 50 billion per year. While the taxes in the special energy account were originally designed to improve Japan's energy supply mix, the change was part of the first phase of addressing Kyoto goals by reducing carbon emissions. The second phase, planned for 2005-07, was to involve a more comprehensive environmental tax system, including a carbon tax.

These developments, despite some scandal in 2002 connected with records of equipment inspections at nuclear power plants, paved the way for an increased role for nuclear energy.

In 2004 Japan's Atomic Industrial Forum (JAIF) released a report on the future prospects for nuclear power in the country. It brought together a number of considerations including 60% reduction in carbon dioxide emissions and 20% population reduction but with constant GDP. Projected nuclear generating capacity in 2050 was 90 GWe. This would mean doubling both nuclear generating capacity and nuclear share to about 60% of total power produced. In addition, some 20 GW (thermal) of nuclear heat would be utilised for hydrogen production. Hydrogen is expected to supply 10% of consumed energy in 2050 and 70% of this would come from nuclear plants.

In July 2005 the Atomic Energy Commission reaffirmed policy directions for nuclear power in Japan, while confirming that the immediate focus would be on LWRs. The main elements were that a "30-40% share or more" should be the target for nuclear power in total generation after 2030, including replacement of current plants with advanced light water reactors. Fast breeder reactors would be introduced commercially, but not until about 2050. Used fuel would be reprocessed domestically to recover fissile material for use in MOX fuel. Disposal of high-level wastes would be addressed after 2010.

In May 2006 the ruling Liberal Democratic Party urged the government to accelerate development of fast breeder reactors (FBRs), calling this "a basic national technology".* It proposed increased budget, better coordination in moving from R&D to verification and implementation, plus international cooperation. Japan was already playing a leading role in the Generation IV initiative, with focus on sodium-cooled FBRs, though the 280 MWe (gross) Monju prototype FBR remained shut down until May 2010, and then shut down again a few months later, with prospective restart repeatedly postponed.

* In April 2007 the government selected Mitsubishi Heavy Industries (MHI) as the core company to develop a new generation of FBRs. This was backed by government ministries, the Japan Atomic Energy Agency (JAEA) and the Federation of Electric Power Companies of Japan. These were concerned to accelerate the development of a world-leading FBR by Japan. MHI has been actively engaged in FBR development since the 1960s as a significant part of its nuclear power business.

METI's 2010 electricity supply plan showed nuclear capacity growing by 12.94 GWe by 2019, and the share of supply growing from 2007's depressed 262 TWh (25.4%) to about 455 TWh (41%) in 2019. This is now unachievable. A regular AEC Policy Planning Council review ceased in 2011 and the Council was disbanded in 2012.

In March 2011 units 1-4 of the Fukushima Daiichi plant were seriously damaged in a major accident, hence written off for decommissioning, which removed 2719 MWe net from Tepco's – and the country's – system. In 2014 units 5&6 joined them in being decommissioned.

At present Japan has 48 reactors totalling 42,569 MWe (net) operational, with two (2756 MWe) under construction, one in indefinite shutdown (Monju), and 12 (16,532 MWe) planned. In the light of mid-2012 policy options Monju is considered more relevant to the R&D section of the Japan Fuel Cycle paper. In 2010 the first of those power reactors then operating reached their 40-year mark (at which stage there was a presumption that some might close down). Some licence extensions have been approved, see subsection below tables.

Post-Fukushima energy policy changes, 2011 on

In July 2011 an Energy & Environment Council (Enecan or EEC) was set up by the Democratic Party of Japan (DPJ) cabinet office as part of the National Policy Unit to recommend on Japan's energy future to 2050.* It was chaired by the Minister for National Policy to focus on future dependence on nuclear power. Its initial review was to recommend that nuclear power's contribution to electricity be targeted at 0%, 15%, or 20-25% for the medium term – a 36% option was dropped.

* The Atomic Energy Commission (AEC) and Central Environment Council apparently came under Enecan in 2011, and in 2012 were restored to previous status.

Meanwhile major Japanese companies such as Mitsui and Mitsubishi started investing heavily in LNG production capacity from Australia and elsewhere eg a 15% stake in Woodside's Browse LNG project for $2 billion. METI estimated that power generation costs would rise by over JPY 3 trillion ($37 billion) per year, an equivalent of about 0.7 percent of gross domestic product, if utilities replaced nuclear energy with thermal power generation. In February 2012 METI's minister said that electricity costs would need to increase up to 15% while the nuclear plants remained shut.*

* Meanwhile, costs of nuclear power relative to alternatives were published. The Institute of Energy Economics of Japan in 2011 put the cost of nuclear electricity generation at ¥8.5 per kWh taking into account compensation of up to ¥10 trillion ($130 billion) for loss or damage from a nuclear accident. Later in the year a draft report for Enecan estimated nuclear generation costs for 2010 to be ¥8.9 per kWh (11.4 US cents). This included capital costs (¥2.5), operation and maintenance costs (¥3.1), and fuel cycle costs (¥1.4). In addition, the estimate included ¥0.2 for additional post-Fukushima safety measures, ¥1.1 in policy expenses and ¥0.5 for dealing with future nuclear risks. The ¥0.5 for future nuclear risks is a minimum: the cost would increase by ¥0.1 for each additional ¥1 trillion ($13 billion) of damage. The ¥8.9 figure was calculated based on a model nuclear power plant using average figures from four plants operating over the period since the 2004 estimate, with an output of 1200 MWe and construction costs of ¥420 billion ($5.4 billion). Costs were calculated assuming a discount rate of 3%, a capacity factor of 70% and a 40-year operating life. The 2010 costs for fossil fuel generation, including costs for CO2 measures, ranged from ¥9.5 for coal through to ¥10.7 for LNG to ¥36.0 for oil. Projecting forward to 2030 the nuclear cost remains stable but fossil fuels costs increase significantly.

In July 2012 feed-in tariffs (FiTs) were introduced for solar and wind power. The solar FiT was ¥42/kWh (41 cents US) for ten years, which was reduced in April 2013 to ¥38 for small systems, and to be reduced again in April 2014 to ¥37/kWh residential and ¥32/kWh for systems over 10 kW. The wind FiT in 2012 was ¥23.1/kWh for units above 20 kW, and ¥57.75 for smaller units (of which none had been approved).

Enecan's "Innovative Energy and Environment Strategy" was released in September 2012, recommending a phase-out of nuclear power by 2040. In the short term, reactors currently operable but shut down would be allowed to restart once they gained permission from the incoming Nuclear Regulation Authority (NRA), but a 40-year operating limit would be imposed. Reprocessing of used fuel would continue. Enecan promised a "green energy policy framework" is promised by the end of 2012, focused on burning imported gas (LNG) and coal, along with expanded use of intermittent renewables. This provoked a strong and wide reaction from industry, with a consensus that 20-25% nuclear was necessary to avoid very severe economic effects, not to mention high domestic electricity prices. In the past year increased fossil fuel imports had been a major contributor to Japan's record trade deficit of JPY 2.5 trillion ($31.78 billion) in the first half of 2012. The Keidanren (Japan Business Federation) said the Enecan phase-out policy was irresponsible, as did the leadership of the Liberal Democratic Party (LDP).

Four days after indicating general approval of the Enecan plan, the DPJ cabinet backed away from it, relegating it as "a reference document" and the prime minister explained that flexibility was important in considering energy policy. The timeline was dropped. Reprocessing used nuclear fuel would continue and there would be no impediment to continuing construction of two nuclear plants – Shimane 3 and Ohma 1. A new Basic Energy Plan would be decided after further deliberation and consultation, especially with municipalities hosting nuclear plants. 

However, at the end of 2012 the new Liberal Democratic Party (LDP) government promptly abolished Enecan, along with the National Policy Institute, so that METI’s Advisory Committee for National Resources and Energy became responsible for formulating energy plans, while MoE’s Central Environment Council focused on climate change matters. The new LDP prime minister ordered a ‘zero-based’ review of energy policies.

In December 2012, after a decisive victory in national elections for the Diet's lower house, with 294 out of 480 seats, the LDP took a more positive view of restarting idled nuclear power plants than its predecessor, which had seemed indifferent to electricity shortages and massive LNG and other fossil fuel import costs. (The DPJ won only 57 seats, down from 267)  The new government said it would take responsibility for allowing reactor restarts after the Nuclear Regulation Authority issued new safety standards and confirmed the safety of individual units. After abolishing Enecan it also said that abandoning reprocessing of used fuel was ruled out. Construction of Shimane 3 and Ohma 1 was to continue, and the construction of up to 12 further units could be approved.

In July 2013, elections for the Diet’s upper house gave the LDP 115 seats out of 242. Its coalition partner and another pro-nuclear party won 29 seats. This consolidated the LDP position and role in reviving the economy, including restoring power supplies. The DPJ with its policy of abandoning nuclear power by 2040 won only 59 seats. The LDP won a seat in every constituency with a nuclear power plant. In Fukushima prefecture the LDP candidate polled more than twice as many votes as the DPJ candidate. In Fukui prefecture, where Kansai Electric Power Co. has 11 units, Japan Atomic Power Co. has two units, and the government has the Monju prototype breeder reactor, an LDP candidate beat the DPJ contender, 237,000 votes to 56,000.

In December 2013 a draft of the new 4th Basic (or Strategic) Energy Plan* was issued, with 20-year perspective, and declaring the period to 2020 as a special stage to reform energy systems. It said that nuclear energy is a key base-load power source and would continue to be utilized safely to achieve stable and affordable energy supply and to combat global warming. However, the degree of dependence on it would be reduced as much as possible consistent with those goals and the maintenance of nuclear technology and expertise. Reactors will be restarted as their safety is confirmed by NRA. Used fuel will receive more attention, and the nuclear fuel cycle will be promoted, including R&D on fast reactors.

* updated every three years, under the Energy Policy law.

In February 2014 METI presented the proposed new 4th Basic Energy Plan to government, which adopted it in April. It lists nuclear as an important one of four base-load options. Two of the others – hydro and geothermal – are limited, and the other is coal, but though cheap, its pollution works against emissions goals and represents a geopolitical risk. Natural gas/LNG was designated as intermediate between low-cost base-load and peaking oil, and capable of complementing the intermittency of renewables. Renewables were given the most space and will be "accelerated to full introduction" though without targets: solar is seen as useful to supply power during peak demand; large-scale deployment of wind could produce significant power, but this would come from northern areas and would require balancing with as-yet undeveloped storage systems. Nuclear power is presented as a quasi-domestic source that gives stable power at low operational cost and with low greenhouse gas profile. Nuclear power is an "important power source that supports the stability of the energy supply and demand structure," it said. 

Later, in October 2014, at least seven of the ten major utilities limited the access of renewable energy to their grids due to potential overloads. The government is addressing the problem by reducing the 2012 high fixed-price feed-in tariffs (FITs).

In January 2015 the Institute of Energy Economics, Japan (IEEJ) released a report looking at four electricity scenarios in 2030 and their implications, for about 1150 TWh (less than 10% up on 2013). They ranged from zero nuclear up to 30% nuclear contribution, with power costs for zero being 42% higher than the 30% nuclear scenario (21.0 vs 14.8 JPY/kWh), and GDP being JPY 10 trillion less. The other metric of obvious significance is energy self-sufficiency, only 7% in 2013, and ranging from 19% in zero-nuclear scenario to 28% in the 30% nuclear one (considering nuclear as quasi-indigenous, as it has been). LNG imports in the zero nuclear scenario are almost as high as in 2013, but reduce 20% from 2013 level in the 30% nuclear one. Reliance on renewables is 35% in zero-nuclear but only 20% in high-nuclear scenario, compared with 13.5% in 2013.

2011-14 Electricity Supply Constraints and Changes and Power Plant Situation

The chairman of Japan's Federation of Electric Power Companies (FEPC) warned in May 2011 that the organization expected the supply-demand balance in summer 2011 would be very tight in the east coast areas served by Tokyo Electric Power Co (Tepco), Tohoku Electric Power Co (both 50 Hz) and Chubu Electric Power Co (60 Hz). He said that all the utilities on the west coast of Japan will cooperate to transfer electricity to the east coast, noting the significant role of nuclear energy in ensuring a stable power supply. However, as noted above, there is a severe constraint on transmission, with only 1.2 GWe of frequency converters available until about 2020.

Under Japanese regulations, the default period between inspections at reactors is 13 months, but changes made in 2009 allow operators to apply to increase this to 18 months. Subject to approval, a five-year introductory period would follow, after which the limit could be raised to 24 months between inspections – more in line with international practices.

The median capacity factor for Japanese nuclear plants is about 70% – compared with over 90% for the best performers worldwide – with the country's inspection requirements a contributing factor to this difference. Most other countries conduct regulatory checks so that utilities can operate their power plants almost all of the time that refuelling or major maintenance is not taking place.

Decline in operating capacity

By mid-May 2011, only 17 out of Japan's 50 remaining nuclear power reactors (apart from Monju and written-off Fukushima Daiichi 1-4) were in operation. This represented 15,493 MWe, or 35%, of the total remaining nuclear generating capacity of 44,396 MWe. Twenty units, with a combined capacity of 17,705 MWe (40% of total nuclear capacity) were not operating as they had been shut for periodic inspections, while another two units (1700 MWe) had been shut for unplanned inspections or equipment replacement. Units 4&5 at Chubu Electric's Hamaoka plant were shut down at the government's request in May 2011 to increase their resistance to tsunamis.*

* Chubu was spending some JPY 140 billion ($1.7 billion) on seawall defences, which were expected to be complete by the end of 2013 (see following subsection). During the shutdown process for the unit 5 ABWR, a burst pipe in the condenser allowed seawater to enter the main cooling circuit and some 5000 litres reached the reactor itself, but disassembly and inspection to December 2012 revealed no serious corrosion damage to fuel assemblies or other components. It is expected to be ready to restart about mid-2014, subject to NRA clearance.

The other nine units – with a combined capacity of 8826 MWe (20% of total nuclear capacity) – were shut down during the 11 March earthquake and have not restarted. These nine reactors – units 1 and 3 of the Onagawa plant, unit 2 of the Tokai plant, all four units at the Fukushima Daini plant and units 5&6 of Fukushima Daiichi – are in cold shutdown and were progressively joined by others as maintenance outages came due. (Four units – Fukushima Daiichi units 1 to 4, total 2719 MWe – were written off and are to be decommissioned. Fukushima Daiichi units 5&6 have joined them in being decommissioned.)

After May 2011 the number of operating reactors steadily dwindled to zero.

In the summer of 2011 stringent energy conservation measures were applied leading to a 12% reduction in power consumption (relative to 2010) in August, and more significantly, a reduction in peak demand reaching 18%, exceeding the government target of 15%.

Tsunami defences

Chubu Electric Power Co is undertaking increased tsunami and flooding protection for the Hamaoka nuclear power plant, which was closed in response to an extraordinary request from the Japanese prime minister. The plant is in a region of high seismic activity, where a large undersea earthquake can be expected within the next 30 years. Behind a row of sand dunes measuring between 10 and 15 metres high above sea level, the company has erected a new 1.6 km breakwater wall reaching 22 metres above sea level. On the main plant site, measures will mitigate general serious flooding in case a tsunami overwhelms the breakwater. They include the waterproofing of diesel generator rooms and seawater pumps, as well as the installation of pumps in the building basements. Grid connections are to be doubled up, with another set of diesel generators complete with long-term fuel supply installed on ground behind the main plant buildings about 25 metres above sea level. Spare parts for seawater pumps will be kept in a hardened building and heavy earthmoving capability will be maintained.

Hokkaido is building a seawall 1.25 km long and up to 6.5 m high at its Tomari site, which is 10 m above sea level.

In April 2012 Kansai announced that it would spend more than JPY 200 billion ($2.5 billion) over four years on defences against earthquakes and tsunamis at its eleven reactors. Kansai submitted the plans to the government as a precondition for restarting its two Ohi reactors in western Japan.

Stress Tests 2011-12

Nuclear risk and safety reassessments – 'stress tests' – along the lines of those in Europe were carried out in 2011. After some confusion the government decided that these would be in two stages.

In the primary stage, plant operators assessed whether main safety systems could be damaged or disabled by natural disasters beyond the plant design basis. This identified the sheer magnitude of events that could cause damage to nuclear fuel, as well as any weak points in reactor design. The 'tests' started from an extreme plant condition, such as operating at full power while used fuel ponds are full. From there, a range of accident progressions such as earthquakes, tsunamis and loss of off-site power were computer simulated using event trees, addressing the effectiveness of available protective measures as problems developed. Stage 1 tests had to be approved before reactors are restarted.

In the second stage even more severe events were considered, with a focus on identifying 'cliff-edge effects' – points in a potential accident sequence beyond which it would be impossible to avoid a serious accident. This stage included the effects of simultaneous natural disasters. A particular focus was the fundamental safety systems that were disabled by the tsunami of 11 March, leading to the Fukushima accident: back-up diesel generators and seawater pumps that provide the ultimate heat sink for a power plant.

The stage 1 stress test results for individual plants were considered first by NISA and then by the Nuclear Safety Commission before being forwarded to the prime minister's office for final approval. Local government must then approve restart.* 

* Late in March 2012 NISA had received stage 1 assessments for 17 reactors – 12 PWRs and 5 BWRs. Three of these – Ohi 1&2 and Ikata 3 – had been approved by NISA and two confirmed by NSC. In September NISA finished reviewing those for six units: Hokkaido’s Tomari 1&2, Kansai’s Takahama 3&4 and Kyushu’s Sendai 1 & 2. Its findings and comments were forwarded to the new Nuclear Regulation Agency (NRA), which is now responsible for approving restarts. It appears that at least 12 stress test assessments then remained at the review stage, including Hokuriku’s Shika 1&2, Genkai 2, 3&4; Mihama 3; Tsuruga 2; Higashidori 1; Takahama 1; Kashiwazaki-Kariwa 1&7; Ohi 1 and Ikata 1.

In mid-April 2012, after a series of high-level meetings, the Japanese government approved the restart of Kansai Electric’s Ohi 3 & 4 reactors, and urged the Fukui governor and the Ohi mayor to endorse this decision. They restarted in July 2012 and ran through to September 2013, when they were shut down for routine maintenance.

Nuclear plant restarts and retirements

In October 2012 the new Nuclear Regulation Authority (NRA) which had taken over from the Nuclear & Industrial Safety Agency (NISA) and NSC announced that henceforth nuclear power plant restart reviews would comprise both a safety assessment by NRA and the briefing of affected local governments by the operators. The assessment would be based on safety guidelines formulated by NRA in July 2013 after public consultation. In rulemaking, the NRA commissioners referred to the guidelines of the IAEA, Finland, France and the USA, as well as the former NISA July 2011 stress test rules and provisional 30-point measures, issued in April 2012, that were applied to the restarts of Ohi 3&4.

Apart from local government consent, NRA procedures are for review of detailed design, followed by approval of that and then inspection, as well as NRA assessment of operating management system, which needs separate approval. Restart can then occur.

PWR applications: In July 2013 four utilities applied for restart of 12 PWR reactors at six sites, two of which – Ohi 3&4 – were already running on interim basis. The units covered by the applications were Kansai's Takahama units 3&4 and Ohi units 3&4; Hokkaido's Tomari units 1-3; Shikoku's Ikata unit 3, and Kyushu's Sendai 1&2 and Genkai 3&4. Gross capacity is 11,200 MWe, almost a quarter of the nation’s total. These were all among the units well advanced in NISA’s stress test assessments in 2012. As of September 2013 the NRA was prioritising six PWR units: Tomari 3, Ikata 3, Sendai 1&2, Genkai 3&4 using four investigation teams with 80 staff. In March 2015 Kansai applied to restart Mihama 3 PWR and Takahama 1&2 PWRs, all with increased seismic and tsunami assumptions.

BWR applications: Tepco delayed its application for Kashiwazaki-Kariwa 6&7 ABWRs pending negotiation with local government, and lodged it in September 2013, lining up a further 2710 MWe gross. The Kashiwazaki-Kariwa 6&7 units were the first BWRs to be put forward for restart. Unlike the 12 PWRs referred to above, BWRs require a filtered containment venting (FCV) system. Under the general terms of a nuclear operator's agreement with local government, prefectural approval is required for these because any use during an emergency would mean releasing radioactivity in the course of avoiding the kind of hydrogen build-up which caused the explosions at Fukushima, destroying the superstructure of three units there.

In December 2013 Chugoku applied for assessment to restart its Shimane 2 reactor, and Tohoku applied for Onagawa 2, both also BWRs. Both companies had obtained local government approval for their applications. Chugoku also plans to apply for an assessment of the Shimane 3 ABWR, almost finished construction, once unit 2 is cleared to restart. J-Power in December 2014 applied for a safety assessment of its Ohma ABWR under construction. In February 2014 Chubu applied for approval to restart Hamaoka 4 BWR, following completion of a major sea wall. It intends to apply to restart unit 3 there in 2015, subject to completing work to conform with NRA regulations, local government agreement, and community acceptance. Unit 5 (1360 MWe ABWR) will also be ready to restart then. In May 2014 Japco applied to restart its Tokai 2 BWR, an older unit. In June Tohoku applied for restart of its relatively new Higashidori BWR, and in August Hokuriku applied for Shika 2 ABWR, the 8th BWR and 20th overall to then.

NRA action: In March 2014 NRA said it would prioritise clearance of Kyushu’s Sendai 1&2 for restart, and in May it said this would be followed by Kansai’s Takahama 3&4. NRA has approved the review reports for these four units, which thus meet safety requirements for restart subject to final changes. Meanwhile a district court has ordered Kansai not to restart its Ohi 3&4 in Fukui prefecture due to public concerns. Kansai, with local government support, has appealed the ruling.

Status of restart applications and safety reviews

Type Utility Reactors Applied Final plan
submitted 
Notes
PWR Kyushu Sendai 1&2 July 2013 Oct 2014 NRA final approval and local govt approval, NRA pre-operation inspection, expect restart August
  Kansai Takahama 3&4 July 2013 Oct 2014 NRA final approval, awaiting local govt approval, but Fukui court injunction issued
  Kansai Ohi 3&4 July 2013  

Quake & tsunami scenarios, but Fukui court injunction issued

  Hokkaido Tomari 1-3 July 2013   Quake scenarios pending
  Shikoku Ikata 3 July 2013 April 2015 Upgrade plan submitted to NRA, 650 Gal seismic
  Kyushu Genkai 3&4 July 2013   Quake & tsunami scenarios
  Kansai Mihama 3 March 2015    
  Kansai Takahama 1&2 March 2015    
ABWR Tepco Kashiwazaki Kariwa 6&7 Sept 2013   NRA doing inspection
  J-Power Ohma 1 Dec 2014   NRA reviewing
BWR Chugoku Shimane 2 Dec 2013   NRA reviewing
  Tohoku Onagawa 2 Dec 2013   NRA reviewing
  Chubu Hamaoka 4 Feb 2014   NRA reviewing
  J-Power Tokai 2 May 2014    
  Tohoku Higashidori 1 June 2014   Question re faults nearby
  Hokuriku Shika 2 August 2014    
Total   24      

The reactor restarts are facing significant implementation costs ranging from US$700 million to US$1 billion per unit, regardless of reactor size or age. To March 2014 the cost was put at $12.3 billion so far. The NRA is working to increase its relicensing staff to about 100 people, which could potentially shorten the currently envisaged six-month review timeline. Under a high case scenario developed by Itochu, about 10 reactors could be added every year for a total of up to 35 reactors back online within five years.

Decommissioning small old units: Media reports in January 2015 said that five old reactors could be closed down permanently, subject to approval by prefecture authorities in Fukui, Shimane and Saga, and approval by METI. All are relatively small (320 to 529 MWe net) and by October 2015 would be more than 40 years old, so that major expenditure on upgrades would be hard to justify even though all of them already had life extension approvals. Two larger units, Kansai’s Takahama 1&2 also reach the 40-year mark in 2015 but these have had significant work done already and the costs of upgrading will be more readily recoverable, though Kansai is uncertain about their future. 

METI approved draft provisions for cost recovery for decommissioning all seven units. In mid-March 2015, Kansai announced that Mihama 1&2 PWRs (320 & 470 MWe net) would be retired, and Japan Atomic Power Co (Japco or JAPC) said it would decommission its Tsuruga 1 BWR (341 MWe), all in Fukui prefecture. Then Chugoku Electric Power Co announced the decommissioning of its Shimane 1 BWR (429 MWe net) in Shimane prefecture, and the Kyushu Electric Power Co did the same for its Genkai 1 PWR (529 MWe net) in Saga prefecture. The total net reduction in operational capacity is 2089 MWe. 

Economic impact of shutdowns

JAIF has said that increased fuel imports are costing about ¥3.8 to 4.0 trillion ($40 billion) per year (METI puts total fossil fuel imports at ¥9 trillion in FY2013). The trade deficit in FY2012 was ¥6.9 trillion ($70 billion), and in 2013 ¥11.5 trillion ($112 billion), up 65% on 2012's figure. For fiscal 2013 the trade deficit was ¥13.75 trillion ($134 billion), 70% up on FY 2012, according to the Ministry of Finance. The total trade deficit from April 2011 to end of March 2014 was thus ¥23.25 trillion ($227 billion), compared with previous surpluses of at least ¥2.5 trillion per year (¥6.6 trillion in 2010). 

Generation cost was up 56% from ¥8.6/kWh to 13.5/kWh in FY 2012. Losses across the utilities are about ¥1 trillion per year. The Ministry of Economy Trade and Industry (MITI) said in April 2013 that Japanese power companies had spent an additional ¥9.2 trillion ($93 billion) to then on imported fossil fuels since the Fukushima accident. In FY 2012 the additional fuel costs to compensate for idled nuclear reactors was ¥3.6 trillion ($35.2 billion), mostly for oil and LNG. In 2013 Japan imported a record 109 million tonnes of coal, and plans to build almost 15 GWe of coal-fired generating capacity were reported.

At the end of 2013 the Japan Business Federation (Keidanren) said that “By stopping nuclear power plants, national wealth of ¥3.6 trillion ($34.9 billion) per year is flowing overseas” due to increased fossil fuel imports. The ongoing slump of trade balance into the negative could lead to deterioration of government credit and must be addressed “with a sense of crisis.” “There can be no new capital investment in domestic industry which is power-intensive.” Keidanren urged the government to recognise that economic growth depends on stable and affordable power, and nuclear needs to be part of that rather than continuing undue reliance on LNG. Also the current feed-in tariff to encourage renewables should be reviewed to reduce its burden on the economy.

In June 2014 three major business lobbies – the Japan Business Federation (Keidanren), the Japan Chamber of Commerce and Industry, and the Japan Association of Corporate Executives (Keizai Doyukai) – submitted a written proposal to the Industry Minister seeking an early restart of the nuclear reactors. “The top priority in energy policy is a quick return to inexpensive and stable supplies of electricity”, they said.

In April 2015 the Institute of Energy Economics, Japan (IEEJ) said that an important economic role of nuclear power in the past was to reduce extreme dependence on imports, and this policy had saved Japan from sending ¥33 trillion ($276 billion) overseas. "We are effectively living on these savings and we may lose about two thirds by 2020 if we stay on this course," due to the "drain of national wealth" caused by ¥3.6 trillion ($30 billion) being spent on imported fuel each year simply to compensate for idled reactors.

In early 2014 some 92 mostly very old oil-burning generation plants were running to full capacity, and these will be the first to shut down, due both to age and cost of running with imported oil.

Climate change effects

Carbon dioxide intensity from Japan's electricity industry climbed again in FY2012, reaching levels 39% greater than when the country's nuclear reactors were operating normally, and taking the sector far beyond climate targets. About 100 million tonnes per year more CO2 is being emitted than when the reactors were operating, adding 8% to the country’s emissions. Emissions from electricity generation accounted for 486 Mt CO2 (36.2%) of the country's total in fiscal 2012, compared with 377 Mt (30%) in 2010.

Up to March 2011 the CO2 intensity of Japan’s power generation was 350 g/kWh. Over the next year, with progressive reactor shut-downs, it rose to 487 g/kWh in FY 2012. In FY 2013 the country’s overall emissions rose to 1395 million tonnes of CO2 equivalent, the highest since records began in 1990. Among Japan's climate change goals was for the electricity sector to reduce carbon intensity by 20% from 1990 levels, to 334 g/kWh CO2 on average, over the five years from 2008 to 2012.

On the eve of the UN climate change meeting in Warsaw in November 2013, Japan’s Minister of the Environment announced that his country was changing its CO2 emission reduction target from 25% lower than 1990 levels by 2020 to a 3.1% increase from then, or 3.8% reduction from 2005 levels. He cited the shutdown of Japan’s 50 nuclear power reactors, some possibly for an extended period, as a prime reason for this, forcing reliance on old fossil fuel plant. In FY 2013 emissions were 0.8% up on 2005 levels and 10.8% higher than 1990, at 1408 Mt CO2. Early in 2015 the Research Institute of Innovative Technology for the Earth said that CO2 emissions were 10.8% above 1990 levels.

Early in 2015 the government was considering a target of 20% reduction in greenhouse gas emissions from the 2005 level by 2030, which might be achieved with 45% of electricity generation being nuclear and renewables. The ruling LDP was reported to be in favour of 30% CO2 reduction.

Reactor development 1970 on

In the 1970s a prototype Advanced Thermal Reactor (ATR) was built at Fugen. This had heavy water moderator and light water cooling in pressure tubes and was designed for both uranium and plutonium fuel, but paticularly to demonstrate the use of plutonium. The 148 MWe unit, started up in 1978, was the first thermal reactor in the world to use a full mixed-oxide (MOX) core. It was operated by JNC until finally shut down in March 2003. Construction of a 600 MWe demonstration ATR was planned at Ohma, but in 1995 the decision was made not to proceed.

Since 1970, 30 BWRs (including four ABWRs) and 24 PWRs have been brought into operation. All the PWRs, comprising 2-, 3-, and 4-loop versions (600 to 1200 MWe classes) have been constructed by Mitsubishi.

ABWR

The first ABWRs (of 1315 MWe) were Tokyo Electric Power Co's (Tepco's) Kashiwazaki-Kariwa units 6 & 7 which started up in 1996-97 and are now in commercial operation. These were built by a consortium of General Electric (USA), Toshiba and Hitachi. Four further ABWRs – Hamaoka 5, Shika 2, Shimane 3 and Ohma 1 – are in operation or under construction, and eight of the planned reactors in Japan are ABWR. These have modular construction. Hitachi-GE talks of its 1500 MWe class "global unified ABWR", and is developing a high-performance 1800 MWe class ABWR. Hitachi was also developing 600, 900 and 1700 MWe versions of the ABWR

APWR

The 1500 MWe class APWR design is a scale-up of the four-loop PWR and has been developed by four utilities with Mitsubishi and (earlier) Westinghouse. The APWR is in the process of being licensed in Japan with a view to the first 1538 MWe units being constructed at Tsuruga (units 3&4). Approval by Fukui prefecture was given in March 2004. It is simpler than present PWRs, combines active and passive cooling systems to greater effect, and has over 55 gigawatt days per tonne (GWd/t) burn-up. Design work continues and will be the basis for the next generation of Japanese PWRs. The APWR+ is 1750 MWe and has full-core MOX capability.

Mitsubishi Heavy Industries (MHI) is now marketing its 1700 MWe APWR in the USA and Europe, and lodged an application for US design certification in January 2008. The US-APWR has been selected by TXU (now Luminant) for Comanche Peak, Texas, and by Dominion for its North Anna plant. (MHI also participated in developing the Westinghouse AP1000 reactor, but now that Westinghouse has been sold to Toshiba, MHI will develop PWR technology independently.)

Next-generation LWR

In mid-2005 the Nuclear Energy Policy Planning Division of the Agency for Natural Resources and Energy instigated a two-year feasibility study on development of next-generation LWRs. The new designs, based on ABWR and APWR, are to lead to a 20% reduction in construction and generation costs and a 20% reduction in spent fuel quantity, with improved safety and three-year construction and longer life. They will have at least 5% enriched fuel and a design life of 80 years with 24-month operating cycle, and be deployed from about 2020. In 2008 the Nuclear Power Engineering Center was established within the Institute of Applied Energy to pursue this goal, involving METI, FEPC and manufacturers. The project is expected to cost JPY 60 billion over eight years, to develop one BWR and one PWR design, each of 1700-1800 MWe. The government, with companies including Toshiba and Hitachi-GE, will share the cost of these. The PWR is to have thermal efficiency of 40%. Basic designs are to be finished by 2015, with significant deployment internationally by 2030.

Power reactors operational in Japan

Reactor Type Net capacity Utility Commercial Operation Planned shutdown
Fukushima II-1
BWR
1067 MWe
TEPCO
April 1982
 
Fukushima II-2
BWR
1067 MWe
TEPCO
February 1984
2024
Fukushima II-3
BWR
1067 MWe
TEPCO
June 1985
 
Fukushima II-4
BWR
1067 MWe
TEPCO
August 1987
 
Genkai 2
PWR
529 MWe
Kyushu
March 1981
 
Genkai 3
PWR
1127 MWe
Kyushu
March 1994
 
Genkai 4
PWR
1127 MWe
Kyushu
July 1997
 
Hamaoka 3
BWR
1056 MWe
Chubu
August 1987
 
Hamaoka 4
BWR
1092 MWe
Chubu
September 1993
 
Hamaoka 5
ABWR
1325 MWe
Chubu
January 2005
 
Higashidori 1 Tohoku
BWR
1067 MWe
Tohoku
December 2005
 
Ikata 1
PWR
538 MWe
Shikoku
September 1977
 
Ikata 2
PWR
538 MWe
Shikoku
March 1982
2022
Ikata 3
PWR
846 MWe
Shikoku
December 1994
 
Kashiwazaki-Kariwa 1
BWR
1067 MWe
TEPCO
September 1985
 
Kashiwazaki-Kariwa 2
BWR
1067 MWe
TEPCO
September 1990
 
Kashiwazaki-Kariwa 3
BWR
1067 MWe
TEPCO
August 1993
 
Kashiwazaki-Kariwa 4
BWR
1067 MWe
TEPCO
August 1994
 
Kashiwazaki-Kariwa 5
BWR
1067 MWe
TEPCO
April 1990
 
Kashiwazaki-Kariwa 6
ABWR
1315 MWe
TEPCO
November 1996
 
Kashiwazaki-Kariwa 7
ABWR
1315 MWe
TEPCO
July 1997
 
Mihama 3
PWR
780 MWe
Kansai
December 1976
 
Ohi 1
PWR
1120 MWe
Kansai
March 1979
 
Ohi 2
PWR
1120 MWe
Kansai
December 1979
 
Ohi 3
PWR
1127 MWe
Kansai
December 1991
 
Ohi 4
PWR
1127 MWe
Kansai
February 1993
 
Onagawa 1
BWR
498 MWe
Tohoku
June 1984
2024
Onagawa 2
BWR
796 MWe
Tohoku
July 1995
 
Onagawa 3
BWR
796 MWe
Tohoku
January 2002
 
Sendai 1
PWR
846 MWe
Kyushu
July 1984
 
Sendai 2
PWR
846 MWe
Kyushu
November 1985
 
Shika 1
BWR
505 MWe
Hokuriku
July 1993
 
Shika 2
ABWR
1304 MWe
Hokuriku
March 2006
 
Shimane 2
BWR
791 MWe
Chugoku
February 1989
 
Takahama 1
PWR
780 MWe
Kansai
November 1974
2024
Takahama 2
PWR
780 MWe
Kansai
November 1975
2025
Takahama 3
PWR
830 MWe
Kansai
January 1985
 
Takahama 4
PWR
830 MWe
Kansai
June 1985
 
Tokai 2
BWR
1060 MWe
JAPC
November 1978
 
Tomari 1
PWR
550 MWe
Hokkaido
June 1989
 
Tomari 2
PWR
550 MWe
Hokkaido
April 1991
 
Tomari 3 PWR 866 MWe Hokkaido December 2009
 
Tsuruga 2
PWR
1110 MWe
JAPC
February 1987
 
Total: 43 reactors
 
40,480 MWe

Fukushima II = Fukushima Daini
The 2015 shutdown dates above are subject to METI approval in mid-2015. The later dates are NISA or NRA approved. 
In 2006 NISA ordered Hamaoka 5 and Shika 2 to be shut down due to problems with steam turbine blades. They were then restarted at lower power levels – 1212 and 1108 MWe net respectively. In 2011 Hamaoka 5 reverted to the above net power level.

Japanese reactors under construction

Reactor Type Gross capacity Utility Construction start Operation*
Monju** Prototype FNR
280 MWe
(246 net)
JAEA   Operated 1994-95, then May-Aug 2010
Shimane 3
ABWR
1373 MWe
Chugoku
December 2005, suspended 2011
deferred, TBD
Ohma 1 ABWR 1383 MWe EPDC/ J-Power May 2010, suspended 3/11 to 10/12 start-up end 2020, comm operation early 2022
total (2 + Monju)
 
3036 MWe
 
 
 
* Latest announced commercial operation. TBD = to be determined.
** Monju operation is outlined in Fast Neutron Reactor section below. It is listed here in line with JAIF categorisation, and is under performance test process. JAEA rather than any utility is responsible for it and WNA may move it to the R&D section of this paper when its future is clearer. IAEA PRIS database lists it as ‘long-term shutdown’.

Japanese reactors planned and proposed

Reactor Type MWe gross
(each)
Utility start *
construction
start *
operation
Tsuruga 3
APWR
1538
JAPC
deferred
7/2017
Tsuruga 4
APWR
1538
JAPC
deferred
7/2018
Higashidori 1 Tepco
ABWR
1385
Tepco
deferred
 
Kaminoseki 1
ABWR
1373
Chugoku
6/2012
(deferred 3/11)
TBD
Sendai 3
APWR
1590
Kyushu
3/2014
(deferred 4/11)
TBD
Higashidori 2 Tepco
ABWR
1385
Tepco
deferred
 
Hamaoka 6 ABWR 1380 Chubu 2016 or later TBD
Higashidori 2 Tohoku
ABWR
1385
Tohoku
2016
TBD
Kaminoseki 2
ABWR
1373
Chugoku
2018
(deferred 6/11)
TBD
Total Planned (9)  
12,947 MWe
 
 
 
Fukushima I-7
ABWR
1380
Tepco
4/2012 (suspended)
 
Fukushima I-8
ABWR
1380
Tepco
4/2012 (suspended)
 
Namie-odaka
ABWR
1385
Tohoku
suspended
 
Total proposed (3)
 
4145 MWe
 
 
 

* According to METI FY2010 plan, unless updated by company. TBD = to be determined.
Tsuruga 3&4 and Tepco's Higashidori 1 were undergoing final safety assessment by regulatory authorities. The units listed as Fukushima I-7&8 and Namie-Odaka will be built elsewhere if at all.

Japanese Nuclear Facilities

Life extension and 30-year reviews

Power reactors are licensed for 40 years and then require approval for life extension in 10-year increments. At 30 years, the regulator must review and approve the utility’s ageing management plan for each reactor. Following the Fukushima accident, the government tightened requirements for approving life extension beyond 40 years, which became the default limit. Operators can apply for up to 20-year licence extensions from 40 years, allowing possible 60 years as in the USA.

The Nuclear & Industrial Safety Agency (NISA) granted a 10-year licence extension for Fukushima Daiichi 1 in February 2011, after technical review and some modifications in 2010. However, this was destroyed in the 2011 accident.

In March 2010, local government approved life extension to 2016 for JAPC's Tsuruga 1, which started commercial operation in March 1970. A year earlier JAPC issued a technical evaluation of the reactor with a plan for its ongoing maintenance. METI approved this in September 2009. (JAPC then applied for life extension to 2016 in order to bridge the gap until units 3&4 at Tsuruga come on line. Construction of the two units was due to start later in 2010 and commissioning of the first was due in March 2016.)

Then Kansai applied for a 10-year licence extension from November 2010 for its Mihama 1 PWR. NISA approved Kansai's long-term maintenance and management plan for the unit and granted a life extension accordingly in June 2010, which was then agreed by local government. However, this effectively means simply that the reactor did not have to be decommissioned then, but may be upgraded according to new standards. Kansai in July 2011 applied for approval of its ageing management plan for Mihama 2, and NISA granted this in July 2012. In February 2014 the NRA approved Chugoku’s Shimane 1 BWR similarly, and in November 2014 they approved a 10-year life extension for Kansai’s Takahama 1 PWR. Subject to required upgrades to new safety standards, all these can now be licensed to 50 years. In October 2014 Kyushu applied for a ten-year extension for Genkai 1. Kansai has applied for ten-year cold shutdown of Takahama 2 to defer any decision on its future beyond its 40th anniversary in 2015. In April 2015 NRA approved a ten-year life extension for it.

In March 2012 NISA and METI approved Shikoku Electric's strategy for managing ageing and hence approved operation of its Ikata 2 PWR for 40 years, and in 2014 approved the same for Tepco’s Fukushima Daini 2 and Tohoku’s Onagawa 1 BWR. In June 2014 Kansai sought approval for Takahama 4, which joined Takahama 3 and Kyushu’s Sendai 1 in being reviewed at 30 years and approved for age-related degradation issues. In January 2015 the NRA approved these issues being handled together with engineering work involved with Kansai meeting safety requirements for restart of the two Takahama units. However, none of the reactors can be restarted until NRA assesses that they conform to its 2013 safety guidelines.

Particular plants: most under construction and planned

Chugoku's Shimane 3 was to enter commercial operation in December 2011, but this was delayed to March 2012 because control rod drives had to be returned to the manufacturer for modification and cleaning. The start-up date was then deferred until evaluation of the Fukushima accident could be undertaken. It was 94% complete when construction was suspended in March 2011. Chugoku finished building a 15 m high sea wall in January 2012, and then extended this to a total length of 1.5 km to also protect Shimane 1&2. Chugoku plans to apply for a safety assessment to clear the way for it to start, so that construction can be completed, once unit 2 is cleared to restart. Seismic rating of the unit is 1000 Gal.

The Electric Power Development Corp, now known as J-Power, is building its Ohma nuclear plant – 1383 MWe Advanced Boiling Water Reactor (ABWR) – in Aomori prefecture. Construction of unit 1 was due to start in August 2007 for commissioning in 2012, but was delayed by more stringent seismic criteria, then delayed again in 2008, and commenced in September 2009. Seismic criterion is now 650 Gal. Construction was suspended for 18 months after the Fukushima tsunami, with it 38% complete – JSW had completed manufacturing the major components. J-Power in mid-2012 affirmed its intention to complete and commission the unit, and announced resumption of work in October. In November 2014 J-Power said that it plans to complete construction by the end of 2020, and have it in commercial operation about 12 months later.  It applied to NRA for safety review in December 2014.

Apart from the Fugen experimental Advanced Thermal Reactor (ATR), this will be the first Japanese reactor built to run solely on mixed oxide (MOX) fuel incorporating recycled plutonium. It will be able to consume a quarter of all domestically-produced MOX fuel and hence make a major contribution to Japan's "pluthermal" policy of recycling plutonium recovered from used fuel.

Tepco struggled for two years with the loss of its Kashiwazaki-Kariwa capacity – nearly half of its nuclear total – following the mid 2007 earthquake. While the actual reactors were undamaged, some upgrading to improve earthquake resistance and also major civil engineering works were required before they resumed operation. Overall, the FY2007 (ending March 2008) impact of the earthquake was estimated at JPY 603.5 billion ($5.62 billion), three quarters of that being increased fuel costs to replace the 8000 MWe of lost capacity. The Nuclear & Industrial Safety Agency (NISA) approved the utility's new seismic estimates in November 2008, and conducted final safety reviews of the units as they were upgraded and then restarted, the first in May 2009. Tepco undertook seismic upgrades of units 1 and 5, the two oldest, restarting them in 2010.

Review of earthquake design criteria meant that construction of Tepco's Higashidori 1&2 and Fukushima Daiichi 7&8 were delayed, requiring investment in coal-fired (1.6 GWe) and gas plant (4.5 GWe of LNG) to fill the gap. However, METI approved Tepco's Higashidori 1 in December 2010 and NISA approved it in January 2011, allowing Tepco to begin work on the site. Work stopped after the Fukushima accident, though JSW started manufacturing major components in 2011 after the accident. Tepco before this had forecast its overall nuclear capacity increasing from 24% of total in FY2007 to 27% of total in 2017, and nuclear output increasing from 23% to 48% of total supply in the same period. It then announced suspension of plans to build ABWR units 7&8 at Fukushima Daiichi. In 2012 it was reported that it could not afford to proceed with Higashidori, and both are probably cancelled.

The three approved plants are to be allowed to complete construction, despite the government's plans for scaling back nuclear power by 2040, according to the trade minister in September 2012.

Tohoku's Higashidori 2 on the same site as Tepco's is scheduled for construction start in 2016, though the company has yet to decide whether to proceed. The site is in Higashidori-mura, on the Pacific coast, near Mutsu on the eastern side of the Shimokita Peninsula in Aomori Prefecture. The company is building a 2km seawall to protect the site.

Chubu's Hamaoka 1&2 reactors, closed in 2001 and 2004 respectively for safety-related upgrades, remained shut down following the mid 2007 earthquake. In December 2008 the company decided to write them off (JPY 155 billion, $1.7 billion) and build a new one there. Modifying the two 1970s units to current seismic standards would cost about double the above amount and be uneconomic. The 540 and 840 MWe units (515 & 806 MWe net), which started operation in 1976 & 1978, will be replaced by a single new one, Hamaoka 6, to start operating in 2020, though in April 2011 the company deferred construction start until 2016. Hamaoka is the company's only nuclear site, though it said that it recognizes that nuclear needs to be a priority for both "stable power supply" and environment. However, the shutdown of units 3-5 in May 2011 by government edict for modification has set back plans.

Japan Atomic Power Co first submitted plans for its Tsuruga units 3&4 to NISA in 2004, and after considerable delay due to siting problems, they were approved by the Fukui prefecture. JAPC then submitted a revised construction application based on new geological data to NISA in October 2009. The approval process, including safety checks by METI, was expected to take two years, but the process then passed to the new NRA. In December 2012 the NRA said that a fault zone directly beneath the existing Tsuruga unit 2 reactor (operating since 1987) was likely to be seismically active, and in May 2013 it endorsed an expert report saying that the reactor poses a risk in the event of a major earthquake. An international review group investigating the faults with a massive excavation concluded in 2014 that the faults were not active, but the NRA accepted another report in March 2015 saying that there was an active fault, making its restart unlikely. The matter may have implications for the planned units 3&4 and also for unit 1. 

JAPC would need to spend JPY 140 billion ($1.75 billion) on civil engineering for site preparation, including land reclamation and a breakwater before construction start for units 3 & 4. Construction – estimated at JPY 770 billion (US$ 7.4 billion) – was due to start in March 2012 with commercial operation in 2017-18. This would be the first Mitsubishi APWR plant, with each unit 1538 MWe. JAPC planned to continue operating Tsuruga 1 beyond its scheduled shutdown date of 2010 and obtained an extension of the licence to 2016, due to the delay with the new units. Some of the power will be supplied to Chubu.

Kyushu Electric Power Co. filed a draft environmental statement ith METI in October 2009 for its Sendai 3 plant, also an APWR, but 1590 MWe. The Ministry of Environment told METI that the project was "absolutely essential, not just for ensuring energy security and a stable supply of electricity... but also to reduce greenhouse gas emissions." Local government has given approval. In 2010 METI began the process of designating it a key power source development project. Subject to METI and NISA approval, Kyushu expects to start construction in March 2014, for commercial operation in December 2019.

Chugoku Electric Power Co plans to build two Kaminoseki ABWR nuclear power units on Nagashima Island on the Seto Inland Sea coast in Kaminoseki Town, Yamaguchi Prefecture. Some site works commenced but then halted after the Fukushima accident – 40% of the site is to be reclaimed land. The small island community of Iwaishima a few kilometres away has long opposed the plant. In October 2012 Chugoku confirmed its intention to proceed.

Tohoku Electric Power Co planned to build the Namie-Odaka BWR nuclear power plant from 2017 at Namie town in Minami Souma city in the Fukushima prefecture on the east coast, but indefinitely deferred this project early in 2013.

Further proposed plants

In September 2010 Tepco, Japan's biggest utility, said it planned to invest JPY 2.5 trillion ($30.5 billion) on low-carbon projects domestically by 2020 to generate more than half of its power free of carbon. Most of this capacity will be nuclear. Two ABWR plants for Tepco are listed as planned, and two as proposed.

Early in 2011 Chubu Electric Co announced that it intended to build a new 3000-4000 MWe nuclear plant by 2030, with site and type to be decided. Beyond the planned Hamoka 6 ABWR, this is listed as 3x1350 units proposed in the WNA Reactor Table.

Following the decommissioning of two old Mihama reactors in 2015, Kansai and local government have discussed reviving earlier proposals to replace them at that site with units 4&5.

Fast Neutron Reactors

The Joyo experimental fast breeder reactor (FBR has been operating successfully since it reached first criticality in 1977, and has accumulated a lot of technical data. It is 140 MWt, and has been shut down sine 2007 due to damage to some core components.

The 280 MWe Monju prototype FBR reactor started up in April 1994 and was connected to the grid in August 1995, but a sodium leakage in its secondary heat transfer system during performance tests in December 1995 meant that it was shut down after only 205 days actual operation, until May 2010.* It then operated for 45 days but late in August 2010 it shut down again, due to refuelling equipment falling into the reactor vessel. This was retrieved in June 2011 and replaced with a new one, allowing potential restart in 2012. It produced 246 MWe (net) when it was fully operating. Its oversight passed to JNC (now JAEA), and the Minister for Science & Technology has been eager to see it restarted. In September 2014 the NRA approved JAEA’s management reorganisation for Monju. Its restart is contingent upon NRA approval of a new maintenance program. It has three coolant loops, uses MOX fuel, and produces 714 MWt, 280 MWe gross and 246 MWe net.

* A Supreme Court decision in May 2005 cleared the way for restarting it in 2008, but this was put back to May 2010. METI confirmed early in 2010 that Monju's seismic safety under new guidelines was adequate, and NSC approved its restart and operation for a three-year period, prior to "full operation" in 2014. In line with the Japan Atomic Industry Forum, Monju is listed as 'under construction' in the Table above and in WNA's Reactor Table. IAEA PRIS lists it as 'long-term shutdown'.

JAEA also undertakes FBR and related R&D at Oarai in Ibaraki prefecture, near Tokai-mura.

In mid-2012 the Education, Science & Technology Ministry, MEXT, outlined to the AEC some options for the future of Monju, for which it is responsible through JAEA. If Japan opts for direct underground disposal of used fuel, Monju would be terminated. If the closed fuel cycle with reprocessing is continued, Monju would continue with its original mission to prepare for commercial use of FBRs from 2050, with demonstration unit to operate from 2025. Monju is reported to have cost JPY 1 trillion ($12.5 billion) to build and operate, and its budget for 2012 was JPY 17.5 billion. Early in 2014 its maintenance was reported as costing JPY 50 million per day.

Originally in 1960s the concept was to use fast breeder reactors (FBR) burning MOX fuel, making Japan virtually independent regarding nuclear fuel. But FBRs proved uneconomic in an era of abundant low-cost uranium, so development slowed and the MOX program shifted to thermal LWR reactors.

From 1961 to 1994 there was a strong commitment to FBRs, with PNC as the main agency. In 1967 FBR development was put forward as the main goal of the Japanese nuclear program, along with the ATR. In 1994 the FBR commercial timeline was pushed out to 2030, and in 2005 commercial FBRs were envisaged by 2050. This remains the plan: a demonstration breeder reactor of 500-750 MWe by 2025, and commercial 1500 MWe units by 2050.

In 1999 JNC initiated a program to review promising concepts, define a development plan by 2005 and establish a system of FBR technology by 2015. The parameters were: passive safety, economic competitiveness with LWR, efficient utilisation of resources (burning transuranics and depleted U), reduced wastes, proliferation resistance and versatility (include hydrogen production). Utilities are also involved, with CREIPI and JAEA.

Phase 2 of the JNC study focused on four basic reactor designs: sodium-cooled with MOX and metal fuels, helium-cooled with nitride and MOX fuels, lead-bismuth eutectic-cooled with nitride and metal fuels, and supercritical water-cooled with MOX fuel. All involve closed fuel cycle, and three reprocessing routes were considered: advanced aqueous, oxide electrowinning and metal pyroprocessing (electrometallurgical refining). This work is linked with the Generation IV initiative, where Japan has been playing a leading role with sodium-cooled FBRs. The JAEA 2006 budget gave a significant boost to R&D on the fast breeder fuel cycle with an increase to JPY 34.6 billion.

Some work has been done by JAEA on reprocessing of used fuel from fast reactors, with higher plutonium levels. FEPC envisages aqueous reprocessing which recovers uranium, plutonium and neptunium together, and minor actinides being added to the MOX pellets for burning. JAEA is part of a project under the Generation IV International Forum investigating the use of actinide-laden fuel assemblies in fast reactors – The Global Actinide Cycle International Demonstration (GACID). See Generation IV paper .

In April 2007 the government selected Mitsubishi Heavy Industries (MHI) as the core company to develop a new generation of FBRs, notably the Japan Standard Fast Reactor (JSFR) concept, though with breeding ratio less than 1:1. This is a large unit which will burn actinides with uranium and plutonium in oxide fuel. It could be of any size from 500 to 1500 MWe. The demonstration JSFR model was due to be committed in 2015 and on line in 2025, and a 1500 MWe commercial unit was proposed by MHI for 2050. From July 2007 Mitsubishi FBR Systems (MFBR) has operated as a specialist company. It was responsible for a joint bid with Areva for work on the US Advanced Recycling Reactor project and is part of the Japanese involvement with the French Astrid project (see R&D section in the Japan Fuel Cycle paper).

Early in 2015 Monju remains shut down. Following maintenance and management reforms, in March, NRA outlined steps that could lead to its shut-down order being lifted, but JAEA is expected to take about a year to complete the necessary inspections. One proposal is to focus it on nuclear waste reduction, in line with JAEA research.

Public Opinion

A number of public opinion polls were taken in April and May 2011 following the Fukushima accident. Those in April showed around 50% supported the use of nuclear power at present or increased levels, but as the crisis dragged on the May polls showed a reduction in support to around 40% and a growth in opinion to over 40% of those wanting to decrease it. A steady 15% or so through May- June 2011 wanted it abolished. In March 2013, the proportion opting for increase or status quo had dropped to 22%, while 53% wanted to decrease it and 20% wanted to abolish it.

References:
JAIF Atoms in Japan, various.
Tanaka, H 2006, Japan's nuclear power program, WNA Symposium 2006
JAIF summary of 4th Strategic Energy Plan April 2014