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Nuclear Power in Japan

(October 2008)

• Japan needs to import some 80% of its energy requirements. 
• Its first commercial nuclear power reactor began operating in mid 1966. 
• Nuclear energy has been a national strategic priority since 1973. 
• Today 55 reactors provide some 30% of the country's electricity and this is expected to increase to at least 40% by 2017.

Despite being the only country to have suffered the devastating effects of nuclear weapons in wartime, Japan has embraced the peaceful use of nuclear technology to provide a substantial portion of its electricity. Today, nuclear energy accounts for almost 30% of the country's total electricity production, from 47.5 GWe of capacity (net). There are plans to increase this to 37% in 2009 and 41% by 2017.

In 2006 Japan generated 1073 billion kWh gross, 28% from coal, 23% from gas and 9% from hydro.  Per capita consumption is about 7700 kWh/yr.

As Japan has few natural resources of its own, it depends on imports for some 80% of its primary energy needs. Initially it was dependent on fossil fuel imports, particularly oil from the Middle East. 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.

History: Development of nuclear program & policy

Japan started its nuclear research program in 1954, with Y230 million being budgeted for nuclear energy. The Atomic Energy Basic Law, which strictly limits the use of nuclear technology to peaceful purposes, was introduced in 1955. The law aims to ensure that 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 in 1956 promoted nuclear power development and utilisation. Several other nuclear energy-related organisations were also established in 1956 under this law: the Science & Technology Agency; Japan Atomic Energy Research Institute (JAERI) and the Atomic Fuel Corporation (renamed PNC in 1967 - see below).

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 Ð 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 fundamental 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, with 4400 employees at ten facilities and annual budget of 161 billion yen (US$ 1.7 billion).

Recent energy policy: 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 are:

• continue to have nuclear power as a major element of electricity production.
• recycle uranium and plutonium from spent fuel, initially in LWRs, and have reprocessing domestically from 2005.
• 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 9 to 12 new nuclear plants operating by 2011.

At present Japan has 54 reactors totalling 45,520 MWe on line, with 3 (3300 MWe) under construction and 12 (14,400 MWe) planned.

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 is 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 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 means doubling both nuclear generating capacity and nuclear share to about 60% of total power produced. In addition, some 20 GW (thermal) of nuclear heat will be utilised for hydrogen production. Hydrogen is expected to supply 10% of consumed energy and 70% of this will 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 are that a "30-40% share or more" shall be the target for nuclear power in total generation after 2030, including replacement of current plants with advanced light water reactors. Fast breeder reactors will be introduced commercially, but not until about 2050. Used fuel will be reprocessed domestically to recover fissile material for use in MOX fuel. Disposal of high-level wastes will be addressed after 2010.

In April 2006 the Institute of Energy Economics Japan forecast for 2030 that while primary energy demand will decrease 10%, electricity use will increase and nuclear share will be 41%, from 63 GWe of capacity. Ten new units would come on line by 2030 and Tsuruga-1 would be retired.

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 is already playing a leading role in the Generation IV initiative, with focus on sodium-cooled FBRs, though the 280 MWe Monju prototype FBR remains shut down.

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 are 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 2008 electricity supply plan shows nuclear capacity growing to 61.5 GWe (23.4% of total) by 2017, and the share of supply growing from 2007's depressed 262 TWh (25.4%) to 458.3 TWh (41.5%) in 2017.

Reactor development

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. It was the first thermal reactor in the world to use a full mixed-oxide (MOX) core. The 148 MWe unit 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, 28 BWRs (including two ABWRs) and 23 PWRs have been brought into operation.

The first ABWRs (of 1315 MWe) were Tokyo Electric Power Co's (Tepco's) Kashiwazaki-Kariwa units 6 and 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. Three further ABWRs - Hamaoka-5, Shika-2 and Shimane-3 - are currently being commissioned or are under construction. Hitachi is also developing 600, 900 and 1700 MWe versions of the ABWR. The ABWR-II is 1717 MWe.

The 1500 MWe APWR design 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) from 2009. 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.  (MHI also participated in developing the Westinghouse AP1000 reactor, but now that Westinghouse has been sold to Toshiba, MHI will develop PWR technology independently.)

In mid 2005 the Nuclear Energy Policy Planning Division of the Agency for Natural Resources and Energy instigated a 2-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, 3-year construction and longer life. In September 2007 it was announced that government with industry and utilities would develop new light water reactor designs for deployment about 2020. These will have at least 5% enriched fuel and an 80-year operating life. The project is expected to cost $520 million over eight years to develop one BWR and one PWR design, each of 1700-1800 MWe.

In relation to fast breeder reactors (FBRs), the Joyo experimental FBR has been operating successfully since it reached first criticality in 1977, and has accumulated a lot of technical data. The Monju prototype FBR reactor started up in April 1994, but a sodium leakage in its secondary heat transfer system during performance tests in December 1995 meant that it has not operated since. It produced 246 MWe when it was operating. Its oversight has passed to JNC (now JAEA), and the Minister for Science & Technology has said that its early restart is a key aim. A Supreme Court decision in May 2005 cleared the way for restarting it in 2008, but this has been put back to February 2009. JAEA also undertakes FBR and related R&D at Oarai in Ibaraki prefecture, near Tokai-mura.

At the end of 1998 a small prototype gas cooled reactor, the 30 MWt High Temperature Engineering Test Reactor (HTTR) started up. This was Japan's first graphite-moderated and helium-cooled reactor. It runs at 850°C and in 2004 achieved 950°C, which will allow its application to chemical processes such as thermochemical production of hydrogen. Its fuel is ceramic-coated particles incorporated into hexagonal graphite prisms, giving it a high level of inherent safety. It is designed to establish a basis for the commercialisation of second-generation helium-cooled plants running at high temperatures for either industrial applications or to drive direct cycle gas turbines. By 2015 an iodine-sulfur plant producing 1000 m³/hr of hydrogen is expected to be linked to the HTTR to confirm the performance of an integrated production system.

Power reactors operating in Japan 

Fukushima I = Fukushima Daiichi, Fukushima II = Fukushima Daini

Japanese reactors under construction 

Japanese Reactors planned, on order or invited 

The Electric Power Development Corp, now known as J-Power, is preparing to build its Ohma nuclear plant - a 1383 MWe Advanced Boiling Water Reactor (ABWR) - in Aomori prefecture. Construction was due to start in August 2007 for commissioning in 2012, but was delayed by more stringent seismic criteria. Apart from the Fugen experimental Advanced Thermal Reactor (ATR), this would 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 has been struggling with the loss of its Kashiwazaki Kariwa capacity - nearly half of its nuclear total - following the mid 2007 earthquake. While the actual reactors are undamaged, major civil engineering works are required before they resume operation, which is not expected for some time - possibly late 2008.  Overall, the FY2007 impact of the earthquake is now projected to be JPY 603.5 billion ($5.62 billion), three quarters of that being increased fuel costs to replace the 8000 MWe of lost capacity.  Review of design criteria has meant that construction of Tepco's Higashidori 1 & 2 and Fukushima Daiichi 7 & 8 have been delayed, requiring investment in coal-fired (1.6 GWe) and gas plant (4.5 GWe of LNG) to fill the gap.  However, Tepco forecasts 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.

After some delay due to siting problems, units 3 & 4 of the Tsuruga nuclear power plant were approved by the Fukui prefecture, and Japan Atomic Power Co has sought government approval for construction. The approval process is likely to take two years, and construction - estimated at 770 billion yen (US$ 7.4 billion) - is due to start in 2010 with commercial operation in 2016-17.  This will be the first Mitsubishi APWR plant.

The main company producing the heavy forgings required for nuclear power plants is spending 40 billion Yen ($330 million) from 2007 to increase capacity in advance of orders expected from both China and the USA. Japan Steel Works (JSW) has production and research bases in Hiroshima, Yokohama and Muroran. The Muroran centre, in Hokkaido, hosts the heavy steel works and research laboratory relevant to power generation. Muroran manufactures reactor pressure vessels, steam generator components, generator & turbine rotor shafts, clad steel plates and turbine casings for nuclear power plants. JSW has been manufacturing forgings for nuclear plant components to US Nuclear Regulatory Commission standards since 1974, and around 130 JSW reactor pressure vessels are used around the world - more than one third of the total.

Uranium supply

Japan has no indigenous uranium. Its 2007 requirements of 8872 tU would be met from Australia (about one third), Canada, Kazakhstan and elsewhere.

In 2006 Itochu agreed to purchase 3000 tU from Kazatomprom over ten years and in connection with this Japanese finance contributed to developing the Central Mynkuduk deposit in Kazakhstan. In 2007 Japanese interests led by Marubeni and Tepco bought (apparently) 40% of the Kharasan mine project in Kazakhstan and will take 2000 tU/yr of its production.

Fuel cycle facilities 

Japan has been progressively developing a complete domestic nuclear fuel cycle industry, based on imported uranium.

JAEA operates a small uranium refining and conversion plant, as well as a small centrifuge enrichment demonstration plant, at Ningyo Toge, Okayama prefecture.

While most enrichment services are still imported, Japan Nuclear Fuel Ltd (JNFL) operates a commercial enrichment plant at Rokkasho. This began operation in 1992 using indigenous technology and has seven cascades each of 150,000 SWU/yr, though only two are operating. Its eventual capacity is planned to be 1.5 million SWU/yr. it is now testing a lead cascade of its new Shingata design, and expects to re-equip the plant with this. JNFL's shareholders are the power utilities.

Japan has 6400 tonnes of uranium recovered from reprocessing and stored in France and the UK, where the reprocessing was carried out. In 2007 it was agreed that Russia's Atomenergoprom would enrich this for the Japanse utilities who own it.

At Tokai-mura, in Ibaraki prefecture north of Tokyo, Mitsubishi Nuclear Fuel Co Ltd operates a major fuel fabrication facility, which started up in 1972. Further fuel fabrication plants are operated by Nuclear Fuel Industries (NFI) in Tokai and Kumatori, and JAEA has some experimental mixed oxide (MOX) fuel facilities at Tokai for both the Fugen ATR and the FBR program, with capacity about 10 t/yr for each.

Also at Tokai, JNC (now JAEA) has operated a 90 t/yr pilot reprocessing plant using Purex technology which has treated 1116 tonnes of used fuel between 1977 and its final batch early in 2006. It will now focus on R&D, including reprocessing of MOX fuel. JAEA operates spent fuel storage facilities there and is proposing a further one. It has also opera

ted a pilot high-level waste (HLW) vitrification plant at Tokai since 1995. Tokai is the main site of JAEA's R&D on HLW treatment and disposal.

In 1984, the Federation of Electric Power Companies (FEPC) applied to the Rokkasho-mura village and Aomori prefecture for permission to construct a major complex including uranium enrichment plant, low-level waste (LLW) storage centre, HLW storage centre, and a reprocessing plant. Currently JNFL operates both LLW and HLW storage facilities there, while its 800 t/yr reprocessing plant is under construction and is being commissioned.

Active testing at the new Rokkasho vitrification plant commenced in November 2007, with separated high-level wastes being combined with borosilicate glass. The plant takes wastes from the adjacent reprocessing plant, after uranium and plutonium are recovered from used fuel for recycle, leaving 3% of the used fuel as high-level radioactive waste.

Reprocessing and MOX fuel 

For energy security reasons, and notwithstanding the low price of uranium for many years, Japanese policy since 1956 has been to maximise the utilisation of imported uranium, extracting an extra 25-30% of energy from nuclear fuel by recycling the unburned uranium and plutonium as mixed-oxide fuel (MOX).

The pilot reprocessing plant at Tokai-mura operated 1977-2006 as mentioned above, processing over 1000 tonnes of used fuel and with a Pu-U mixed product.

JNFL's 800 t/yr Rokkasho-mura reprocessing plant is due to start operation in November 2008, following a 28 month test phase plus some delay at the end of 13 years construction. It is based on Areva's La Hague technology and in late 2007 the twenty-year cooperation agreement with Areva was extended and related specifically to Global Nuclear Energy partnership (GNEP) goals. The modified PUREX process now employed leaves some uranium with the plutonium product - it is a 50:50 mix, so there is no separated plutonium at any time, alleviating concerns about potential misuse.

In FY 2007 (to end March 2008) some 210 tonnes of used fuel was reprocessed.  In FY 2008 it is expected to reprocess 395 tonnes of used fuel, from which it will recover 1.9 tonnes of fissile plutonium (in reactor-grade material).

Background: In October 2004 the Atomic Energy Commission advisory group decided by a large majority (30 to 2) to proceed with the final commissioning and commercial operation of JNFL's 800 t/yr Rokkasho-mura reprocessing plant, costing some 2.4 trillion yen (US$ 20 billion). The Commission rejected the alternative of moving to direct disposal of spent fuel, as in the USA. This was seen as a major milestone in the joint industry-government formulation of nuclear policy for the next several decades. The final 22-month test phase for the plant began in March 2006, after 13 years construction. Some 430 tonnes of used fuel will be put through the plant to test all aspects of its operation. This will produce some 2.3 tonnes of reactor-grade plutonium (1.6t fissile Pu). 

A 2004 government study showed that projected over the next 60 years it would be significantly more expensive to reprocess - at 1.6 yen/kWh, compared with 0.9 - 1.1 yen for direct disposal. This translates to 5.2 yen/kWh overall generating cost compared with 4.5 - 4.7 yen, without considering the implications of sunk investment in the new plant, or apparently the increased price of uranium since 2004. 

Until now, the reprocessing of spent fuel has been largely undertaken in Europe by BNFL and AREVA (4200t and 2900t respectively), with vitrified high-level wastes being returned to Japan for disposal. Areva's reprocessing finished in 2005, and full-scale operation of JNFL's reprocessing plant at Rokkasho-mura is scheduled to start in 2008. Used fuel has been accumulating there since 1999 in anticipation of its operation (shipments to Europe finished in 1998).

The new Rokkasho plant will treat 14,000 tonnes of used fuel stockpiled there to end of 2005 plus 18,000 tonnes of used fuel arising from 2006, over some 40 years. It will produce about 4 tonnes of fissile plutonium per year.

The Federation of Electric Power Companies has said that nine member companies will use plutonium as mixed oxide (MOX) fuel in 16-18 reactors from 2010 under the "pluthermal" program. About 6 tonnes of fissile plutonium per year is expected to be loaded into power reactors. Meanwhile MOX fuel fabricated in Europe from some 40 tonnes of separated reactor-grade plutonium (25.6t Puf) from Japanese used fuel can be used. However, local concerns about MOX fuel use slowed implementation of the 1994 "pluthermal" program.

So far, Japan has received three shipments containing over 2 tonnes of its (reactor-grade) plutonium from Europe. The first shipment, in 1992, was simply plutonium oxide and earmarked for use in the Monju prototype FBR. However, Monju has yet to be loaded with this as it remains shut down due to the sodium leak in 1996. The second shipment, in the form of MOX fuel for light water reactors, was in 1999. Part of this shipment from BNFL and intended for use in Kansai Electric Power Co's Takahama plant was found to contain falsified quality control data. The shipment was subsequently returned to the UK in 2002. The third shipment consisted of MOX fuel from BNFL for use in TEPCO's Kashiwazaki-Kariwa-3 reactor.

Two prefectural governments - Fukushima and Niigata - moved to defer the use of MOX fuel at reactors within those prefectures, forcing TEPCO and Kansai to suspend or reschedule their planned use there.  In 2008 the Shizuoka prefecture accepted Chubu's plans to use MOX in its Hamaoka-4 plant.  Fukui prefecture accepts Kansai's planned use of MOX at Takahama-3 and 4 from 2010.

Meanwhile, Japan's plutonium stocks increase - at the end of 2004 there was 41 tonnes of separated reactor-grade plutonium (about 35% fissile) stored and awaiting use in MOX fuel.  At the end of 2007 there was 31.2 tonnes of fissile plutonium (Puf) held by Japanese utilities: 13.9 t in France, 11.3 t in UK and 6.0 t held domestically.  It is estimated that 5.5 to 6.5 tonnes of Puf will be used each year from about 2012.

In April 2005 the Aomori prefecture approved construction of a MOX plant at Rokkasho, adjacent to the reprocessing plant. An agreement was signed by the Governor of the prefecture, the mayor of Rokkasho-mura and the head of JNFL. The Governor urged the Federation of Electric Power Companies "to step up their efforts towards realisation of the MOX-use program." The approval was seen as a significant step forward in closing the fuel cycle in Japan, and was strongly supported by the federal government, Atomic Energy Commission and utilities. JNFL has applied for a licence to build and operate the 130 t/yr J-MOX plant. Construction of terh US$ 1.2 billion plant is expected to begin late in 2007 with operation about 2012.

By end of October 2008 the Nuclear & Industrial Safety Agency (NISA) on behalf of the Ministry (METI) had approved the use of MOX fuel in eight reactors: Takahama 3 & 4, Fukishima I-3, Kashiwazaki Kariwa 3, Genkai 3, Hamaoka 4 and Shimane-2.  This is expected to occur about 2012, after modifications to the reactors.

In November 2006 Shikoku Electric Power has contracted with Mitsubishi to manufacture 21 MOX fuel assemblies for its Ikata nuclear plant using 600 kg of reactor-grade plutonium. The plutonium has been recovered by Areva at La Hague from Shikoku's used fuel and the MOX will be fabricated at Areva's Melox plant, also in France.

Fast Breeder Reactors 

Originally 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.

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 are: 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 (electrorefining). This work is linked with the Generation IV initiative, where Japan is 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 34.6 billion yen.

In September 2006 FEPC put forward a compact sodium-cooled FBR design of 1500 MWe using MOX fuel which it expected to be competitive with advanced LWR designs. Mitsubishi is working on commercialisong this. A smaller demonstration unit was envisaged for 2025.

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). SeeGeneration IV paper .

In April 2007 the government selected Mitsubishi Heavy Industries (MHI) as the core company to develop a new generation of FBRs. From July Mitsubishi FBR Systems will operate as a specialist company, also responsible for a joint bid with Areva for work on the US Advanced Recycling Reactor project - part of the Global Nuclear Energy Partnership based in USA.

High-level wastes

In 1995, Japan's first high-level waste (HLW) interim storage facility opened in Rokkasho-mura. The first shipment of vitrified HLW from Europe (from the reprocessing of Japanese fuel) also arrived in that year. The last of twelve shipments from France was in 2007. Shipments from UK start in 2008.

In 2005 Tepco and JAPC announced that a Recyclable Fuel Storage Centre would be established in Mutsu, operating from 2010 with 5000 t capacity. It will provide interim storage for up to 50 years before used fuel is reprocessed.

In May 2000, the Japanese parliament (the Diet) passed the Law on Final Disposal of Specified Radioactive Waste (the "Final Disposal Law") which mandates deep geological disposal of high-level waste (defined as only vitrified waste from reprocessing spent reactor fuel). In line with this, the Nuclear Waste Management Organisation (NUMO) was set up in October 2000 by the private sector to progress plans for disposal, including site selection, demonstration of technology there, licensing, construction, operation, monitored retrievable storage for 50 years and closure of the repository. Some 40,000 canisters of vitrified HLW are envisaged by 2020, needing disposal - all the arisings from the Japanese nuclear plants until then.

NUMO has begun an open solicitation process to find a site, and will shortlist those that are proffered and potentially suitable. The promising ones will be subject to detailed investigation from 2012. A third phase to 2030 will end with site selection.

Repository operation is expected from about 2035, and the 3000 billion yen (US$ 28 billion) cost of it will be met by funds accumulated at 0.2 yen/kWh from electricity utilities (and hence their customers) and paid to NUMO. This sum excludes any financial compensation paid by the government to local communities.

In mid 2007 a supplementary waste disposal bill was passed which says that final disposal is the most important issue in steadily carrying out nuclear policy. It calls for the government to take the initiative in helping the public nationally to understand the matter by promoting safety and regional development, in order to get the final disposal site chosen with certainty and without delay. It also calls for improvement in disposal technology in cooperation with other countries, revising the safety regulations as necessary, and making efforts to recover public trust by, for example, establishing a more effective inspection system to prevent the recurrence of data falsifications and cover-ups.

The technical aspects of Japan's HLW disposal concept is based on two decades' work under JNC (now JAEA) involving generic evaluation of repository requirements in Japan's geology. The technical aspects of Japan's HLW disposal concept is based on two decades' work under JNC (now JAEA) involving generic evaluation of repository requirements in Japan's geology. Since 2000 the Horonobe Underground Research Centre has been under development on Hokkaido, investigating sedimentary rocks about 500m deep, and in November 2005 construction of the underground shafts and galleries was launched. JAEA runs the Tona Geoscience Centre at Toki, in Gifu prefecture, and is building a similar facility, the Mizunami Underground Research Laboratory there, in igneous rock about 1000m deep.

The basic repository concept involves sealing about 20 HLW canisters in a massive steel cask or overpack and surrounding this by bentonite clay. NUMO has built design options on this including those allowing inspection and retrieval over long periods. In particular the Cavern Retrievable (CARE) concept has emerged, involving two distinct stages: ventilated underground caverns with the wastes in overpacks (hence shielded) fully accessible, followed by backfilling and sealing the caverns after 300 years or so. The initial institutional control period allows radiological decay of the wastes so that thermal load is much reduced by stage 2 and hence the concept allows a much higher density of wastes than other disposal concepts.

The CARE concept can be adapted for spent fuel, the cask then being similar to shipping casks for such except that a layer of shielding required due to higher thermal and radiation output could be removable before the cavern is backfilled and sealed. However, for spent fuel retrieval would be likely rather than merely possible, since it represents a significant potential fuel resource (via reprocessing), whereas vitrified HLW does not. Also spent fuel would require ease of access due to the need for safeguards inspections. Eventual backfill could include depleted uranium if that is then considered a waste.

In 2004 METI estimated the costs of reprocessing spent fuel, recycling its fissile material and management of all wastes over 80 years from 2005. METI's Electricity Industry Committee undertook the study, focused on reprocessing and MOX fuel fabrication including the decommissioning of those facilities (but excluding decommissioning of power reactors). Total costs over 80 years amount to some 19 trillion yen, contributing almost one yen (US 0.9 cents) per kilowatt-hour at 3% discount rate. About one third of these costs would still be incurred in a once-through fuel cycle, along with increased high-level waste disposal costs and increased uranium fuel supply costs. Japan's policy however is based on energy security rather than purely economic criteria.

Funding arrangements for HLW were changed in October 2005 under the new Back-end Law which set up the Radioactive Waste Management Funding and Research Centre (RWMC) as the independent funds management body. All reserves held by utilities will be transferred to it and companies will be refunded as required for reprocessing.

Decommissioning 

The original Tokai-1 power station, a British Magnox reactor which closed down in 1998, is being decommissioned over 20 years, the first ten as "safe storage" to allow radioactivity to decay.  Phase 1 (to 2006) comprised preliminary work, in Phase 2 (to 2011) the steam generators and turbines will be removed, and in Phase 3 (to 2018) the reactor will be dismantled, the buildings demolished and the site left ready for re-use.  All radioactive wastes will be classified as low-level (LLW), albeit in three categories, and will be buried - the 1% of level I wastes 50-100 metres deep.  The total cost will be 93 billion yen - 35 billion for dismantling and 58 billion for waste treatment including the graphite moderator (which escalates the cost significantly).

Fugen ATR (148 MWe) closed in March 2003, and JAEA plans to decommission it and demolish to clear the site by 2029, at a total cost of about 70 billion yen, including waste treatment and disposal.  Plans for this were approved in February 2008.

JAEA is responsible for research on reactor decommissioning.

Regulation and safety 

The Nuclear & Industrial Safety Agency (NISA) within the Ministry of Economy Trade & Industry (METI, the successor of MITI) is responsible for nuclear power regulation, licensing and safety. It conducts regular inspections of safety-related aspects of all power plants.

The Nuclear Safety Commission is a more senior government body set up in 1978 under the Atomic Energy Basic Law and is responsible for formulating policy, alongside the Atomic Energy Commission. Both are part of the Cabinet Office.

The Science & Technology Agency was responsible for safety of test and research reactors, nuclear fuel facilities and radioactive waste management, as well as R&D, but its functions were taken over by NISA in 2001.

Public support for nuclear power in Japan has been eroded in the last few years due to a series of accidents and scandals. The accidents were the sodium leak at the Monju FBR, a fire at the JNC waste bituminisation facility connected with its reprocessing plant at Tokai, and the 1999 criticality accident at a small fuel fabrication plant at Tokai. The criticality accident, which claimed two lives, happened as a result of workers following an unauthorised procedures manual. None of these accidents were in mainstream civil nuclear fuel cycle facilities.

Following the 1999 Tokai criticality accident, electric power companies, along with enterprises involved with the nuclear industry established the Nuclear Safety Network (NSnet). The network's main activities were to enhance the safety culture of the nuclear industry, conduct peer reviews, and disseminate information about nuclear safety. In 2005 this was incorporated into the Japan Nuclear Technology Institute, based on the US Institute of Nuclear Power Operations. The NSnet division cooperates with INPO and WANO and arranges peer review activities.

Japan's Nuclear Safety Commission confirmed in April 2002 that using mixed oxide (MOX) fuel is safe, and that its use at up to 18 reactors by 2010 was supported. Senior members of the government have reaffirmed that the country's use of MOX "must happen", and that the government will initiate educational and information programs to win wider acceptance for it. A local referendum last year has delayed plans for its introduction.

In 2002 a scandal erupted over the documentation of equipment inspections at Tepco's reactors, and extended to other plants. While the issues were not safety-related, the industry's reputation was sullied. Inspection of the shrouds and pumps around the core is the responsibility of the company, which in this case had contracted it out. In May 2002 questions emerged about data falsification and the significance of cracks in reactor shrouds (used to direct water flow in BWRs) and whether faults were reported to senior management. By May 2003 Tepco had shut down all its 17 reactors for inspections, and by the end of 2003 only seven had been restarted. Replacement power cost on average over 50% more than the 5.9 yen/kWh (5.5 cents US) nuclear generation cost. Tepco now has all its reactors back on line, with the whole fiasco costing it about 200 billion yen (US$ 1.9 billion).

In March 2007, as part of an exercise ordered by NISA, reactor owners were combing records to divulge past incidents which were not reported at the time - mostly because they were not required to be. However, it turned up some incidents which should have been reported, including a brief (15 minute) criticality during refuelling at Hokuriku's 540 MWe Shika-1 boiling water reactor (BWR) in 1999. A series of deficiencies and errors contributed to the incident, and clearly more should have been learned from it to benefit other operators of boiling water reactors such as Chubu and Tohoku, which have also had control rod anomalies over the last 20 years. Tepco said that its Fukishima I-3 BWR may have experienced criticality over seven hours during an outage in 1978, when control rods slipped out of position. NISA ordered the Shika-1 reactor to be shut down for detailed checks.

Because of the frequency and magnitude of earthquakes in Japan, particular attention is paid to seismic issues in the siting, design and construction of nuclear power plants. In May 2007 revised seismic criteria were announced which increased the design basis criteria by a factor of about 1.5 and required utilities to undertake some reinforcement of older plants. See also paper on Nuclear Power Plants & Earthquakes.

In July 2007 the Niigata Chuetsu-Oki earthquake occurred on a fault very close to the Kashiwazaki-Kariwa nuclear power plant, and the ground acceleration exceeded the design parameters for the plant, ie it was more severe than the plant was required to be designed for.  The operating reactors shut down safely and there was no damage to the main parts of the plant.  The government (METI) then set up a 20-member Chuetsu Investigation and Countermeasures Committee to investigate the specific impact of this earthquake on the power station, and in the light of this to identify what government and utilities must address to ensure nuclear plant safety. It acknowledged that the government was responsible for approving construction of the first units in the 1970s very close to what is now perceived to be a geological fault line.  It was also agreed that the  International Atomic Energy Agency (IAEA) would join Japan's Nuclear Safety Commission in a review of the situation. The second IAEA team confirmed after inspecting key internal components that there was apparently "no significant damage to the integrity of the plant". Ground subsidence damaged much equipment around the seven reactors, but the main part of each plant is built on bedrock, which entailed excavation in some places to 45 metres.

In October 2008 the Nuclear and Industrial Safety Agency (NISA) presented to the Nuclear Safety Commission (NSC) its evaluation of Tepco's report on Kashiwazaki Kariwa, assessing it as "appropriate".  It contained the results of Tepco's inspections and assessments of equipment, buildings and other structures at the plant following the July 2007 earthquake.

International outlook

Apart from some active interest in uranium exploration and mine investment in Australia and Canada to help secure fuel supplies, for many years the Japanese nuclear industry was focused domestically, but in the 1990s it started to look at export possibilities and international collaboration.

Companies such as Hitachi, Mitsubishi and Toshiba formed important alliances internationally or took over major foreign nuclear companies.

At the government level, there were agreements with several governments including Kazakhstan.  Then NISA set up the International Nuclear Power Safety Working Group in 2008 to cooperate in the field of nuclear safety with emerging countries, primarily in Asia, planning to introduce and expand their use of nuclear power. 

In June 2008 an agreement on high-temperature gas-cooled reactor research was initialled by JAEA and the Kazakhstan Atomic Energy Committee, focused on small cogeneration plants.

Non-proliferation 

The Atomic Energy Basic law prohibits the military use of nuclear energy and successive governments have articulated principles reinforcing this. In 1976 Japan became a party to the Nuclear Non-Proliferation Treaty with its safeguards arrangements administered by the UN's International Atomic Energy Agency, and in 1999 it was one of the first countries to ratify the Additional Protocol with IAEA, accepting intrusive inspections.

Japan is noteworthy in being the only non-weapons state under the NPT with major fuel cycle facilities, which are thus under full safeguards. The Rokkasho reprocessing plant is the first such plant to be under full IAEA safeguards (others are under Euratom safeguards). Monitoring equipment funded by IAEA was built in to the plant, which was a novel challenge for both IAEA and JNFL.

Japan also has bilateral safeguards arrangements with its major nuclear supplier states and has long been a member of the Nuclear Suppliers Group which restricts export of nuclear equipment.

References:
Nuclear Engineer, vol.40, no.5, September/October 1999, p.186-191.
Country Nuclear Power Profiles, IAEA, 1998, p.285-313.
OECD/NEA 1995, Japan
 Nuclear Review, no.394, June 2001, p.14-19.
Nuclear Fuel Cycle, TEPCO, March 2002.
Nuclear Power Stations in Japan, CRIEPI, January 2000.
Paper by H Kurihara, WNA Symposium, 2002.
Masuda, S. 2003, HLW Disposal Program in Japan, KAIF/KNS Conference, Seoul.
Ichimiya, M. 2003, Design Study on Advanced Fast Reactor Cycle System in Japan, KAIF/KNS Conference.
Pickett S.E. 2002, Japan's nuclear energy policy, Energy Policy 30, 1337-55, Dec 2002.
Nuclear Engineering International, Oct 1998 & Nov 2004.
JAIF Atoms in Japan, various.
Tanaka, H 2006, Japan's nuclear power program, WNA Symposium 2006.

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