Nuclear Power in Japan

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 (29% in 2009), from 47.5 GWe of capacity (net) to March 2011, and 44.6 GWe (net) from then. There are plans to increase this to 41% by 2017, and 50% by 2030.


  • Japan needs to import some 80% 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.
  • The country’s 50 main reactors provide some 30% of the country’s electricity and this is expected to increase to at least 40% by 2017.
  • Japan has a full fuel cycle set-up, including enrichment and reprocessing of used fuel for recycle.

In 2008 Japan generated 1085 billion kWh gross, 30% from coal, 25% from gas, 24% from nuclear, 11% from oil, and 7.5% from hydro, though 8 GWe of nuclear capacity was shut down for checks following an earthquake in mid 2007. Per capita consumption is about 7900 kWh/yr. Demand for 2009 was expected to be 892 billion kWh, with peak 173.4 GWe, requiring capacity of 194 GWe.

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 (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 seems set 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) has 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% now), 10% from renewables (now 5%) and 30% fossil fuels (now 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 envisages deepening strategic relationships with energy-producing countries. Nuclear power will play a big part in implementing the plan, and new reactors will be required as well as achieving 90% capacity factor across all plants.

A peculiarity of Japan’s electricity grids is that on the main island, Honshu, the northeastern half including Tokyo is 50 Hz, the southwestern half including Nagoya, Kyoto and Osaka is 60 Hz, and there is only 1 GWe of frequency converters connecting them.

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).

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 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.

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 used 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 51 reactors totalling 44,642 MWe (net) operational, with two (2756 MWe) under construction and 12 (16,532 MWe) planned.  In 2010 the first of those now operating reached their 40-year mark, at which stage some may close down. However, JAPC obtained approval for its small Tsuruga unit 1 to continue to 2016, due to 2 x 1538 MWe new capacity at that site being delayed. Then Kansai applied for a 10-year licence extension from November 2010 for its Mihama-1.  The Nuclear & Industrial Safety Agency (NISA) approved Kansai’s long-term maintenance and management policy for the unit and granted a life extension accordingly, which was then agreed by local government.  NISA granted a 10-year licence extension for Fukushima I-1 in February 2011, after technical review and some modifications in 2010.

In March 2011 units 1-4 of the Fukushima Daiichi plant were seriously damaged in a major accident, and appear certain to be written off and decommissioned, removing 2719 MWe net from Tepco’s – and the country’s – system.

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 (gross) Monju prototype FBR remained shut down until May 2010.

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 2010 electricity supply plan shows 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.

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. 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 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. 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 scle-up of the 4-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) from 2010. 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 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 and 3-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.

Fast reactors – FNR

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 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 until May 2010*.  After a few months it then shut down again.  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.  JAEA also undertakes FBR and related R&D at Oarai in Ibaraki prefecture, near Tokai-mura.

* 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 3-year period, prior to “full operation” in 2014.

Mitsubishi Heavy Industries (MHI) is involved with a consortium to build 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. In this connection MHI has also set up Mitsubishi FBR Systems (MFBR). The demonstration FR model is due to be committed in 2015 and on line in 2025, and a 1500 MWe commercial FR is proposed by MHI for 2050.

Power reactors operational in Japan

Reactor Type Net capacity Utility Commercial Operation
Fukushima I-5
BWR
760 MWe
TEPCO
April 1978
Fukushima I-6
BWR
1067 MWe
TEPCO
October 1979
Fukushima II-1
BWR
1067 MWe
TEPCO
April 1982
Fukushima II-2
BWR
1067 MWe
TEPCO
February 1984
Fukushima II-3
BWR
1067 MWe
TEPCO
June 1985
Fukushima II-4
BWR
1067 MWe
TEPCO
August 1987
Genkai-1
PWR
529 MWe
Kyushu
October 1975
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
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-1
PWR
320 MWe
Kansai
November 1970
Mihama-2
PWR
470 MWe
Kansai
July 1972
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
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
BWR
1304 MWe
Hokuriku
March 2006
Shimane-1
BWR
439 MWe
Chugoku
March 1974
Shimane-2
BWR
791 MWe
Chugoku
February 1989
Takahama-1
PWR
780 MWe
Kansai
November 1974
Takahama-2
PWR
780 MWe
Kansai
November 1975
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-1
BWR
341 MWe
JAPC
March 1970
Tsuruga-2
PWR
1110 MWe
JAPC
February 1987
Monju
prototype FNR
246 MWe
JAEA
operated 1994-95, restarted May 2010
Total: 51 reactors
44,642 MWe

Fukushima I = Fukushima Daiichi, Fukushima II = Fukushima Daini

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. When the turbines are repaired, they will revert to the above net power levels.

Japanese reactors under construction

Reactor Type Gross capacity Utility Construction start Operation*
Shimane 3
ABWR
1373 MWe
Chugoku
December 2005
3/2012
Ohma 1 ABWR 1383 MWe EPDC/ J-Power May 2010 11/2014
total (2)
2756 MWe
* Latest announced commercial operation.

Japanese reactors planned

Reactor Type MWe gross
(each)
Utility start *
construction
start *
operation
Tsuruga 3 APWR 1538 JAPC 3/2012 7/2017
Tsuruga 4 APWR 1538 JAPC 3/2012 7/2018
Higashidori 1 Tepco
ABWR
1385
Tepco
4/2011
(deferred)
3/2017
Fukushima I – 7
ABWR
1380
Tepco
4/2012
10/2016
Fukushima I – 8
ABWR
1380
Tepco
4/2012
10/2017
Kaminoseki 1
ABWR
1373
Chugoku
6/2012
3/2018
Sendai 3
APWR
1590
Kyushu
3/2014
(deferred)
12/2019
Higashidori 2 Tepco
ABWR
1385
Tepco
2014?
2019 or later
Hamaoka 6 ABWR 1380 Chubu 2016 2020 or later
Higashidori 2 Tohoku
ABWR
1385
Tohoku
2016
2021 or later
Namie-odaka
BWR?
825?
Tohoku
2017
3/2021
Kaminoseki 2
ABWR
1373
Chugoku
2018
2022
Total (12)
16,532 MWe
* according to METI FY2010 plan, unless updated by company.  Tsuruga 3-4 schedule has slipped by 16 months.
Tsuruga 3-4 and Tepco’s Higashidori 1 are undergoing final safety assessment by regulatory authorities.
Japanese Nuclear Facilities

Life extension

Power reactors are licensed for 40 years and then require approval for life extension. 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 is now due to start later in 2010 and commissioning of the first is due in March 2016.)

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 Electric Power Development Corp, now known as J-Power, is preparing to build 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.  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 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 has meant that construction of Tepco’s Higashidori 1 & 2 and Fukushima Daiichi 7 & 8have been 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.  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.

Tohoku’s Higashidori 2 on the same site is scheduled for construction start in 2016. The site is in Higashidori-mura, on the Pacific coast, on the eastern side of the Shimokita Peninsula in Aomori Prefecture.

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.  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.

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, is likely to take two years. Construction – estimated at JPY 770 billion (US$ 7.4 billion) – is now due to start in March 2012 with commercial operation in 2017-18.  This will be the first Mitsubishi APWR plant, with each unit 1538 MWe.  JAPC will continue operating Tsuruga 1 beyond its scheduled shutdown date of 2010, 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 with 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 have commenced, and 40% of the site is proposed to be reclaimed land. The small island community of Iwaishima a few kilometres away has long opposed the plant.

Tohoku Electric Power Co plans 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.

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.  Four ABWR plants for Tepco are listed as planned.

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 3 x 1350 units proposed in WNA table.

Heavy manufacturing

The main company producing the heavy forgings required for nuclear power plants spent JPY 40 billion ($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.

See also WNA paper on  Heavy manufacturing of power plants.

Uranium supply

Japan has no indigenous uranium. Its 2011 requirements of 8195 tU will be met from Australia (about one third), Canada, Kazakhstan and elsewhere.

Increasingly, Japanese companies are taking equity in overseas uranium projects.

In Kazakhstan, Itochu agreed to purchase 3000 tU from Kazatomprom over ten years in 2006, and in connection with this Japanese finance contributed to developing the West Mynkuduk deposit in Kazakhstan (giving Sumitomo 25%, Kansai 10%). In 2007 Japanese interests led by Marubeni and Tepco bought 40% of the Kharasan mine project in Kazakhstan and will take 2000 tU/yr of its production. A further agreement on uranium supply and Japanese help in upgrading the Ulba fuel fabrication plant was signed in May 2008. In March 2009 three Japanese companies – Kansai, Sumitomo and Nuclear Fuel Industries – signed an agreement with Kazatomprom on uranium processing for Kansai plants.

In Uzbekistan, a Japan-Uzbek intergovernmental agreement in September 2006 was aimed at financing Uzbek uranium development and in October 2007 Itochu Corporation agreed with Navoi Mining & Metallurgy Combinat (NMMC) to develop technology to mine and mill the black shales, particularly the Rudnoye deposit, and to take about 300 tU/yr from 2007. Then in February 2011 Itochu signed a 10-year “large-scale” uranium purchase agreement with NMMC.

In Australia, Mitsui joined Uranium One’s Honeymoon mine project in 2008 as a 49% joint venture partner. Then early in 2009, a 20% share in Uranium One Inc was taken by three Japanese companies, giving overall 59% Japanese equity in Honeymoon. In July 2008 Mitsubishi agreed to buy 30% of West Australia’s Kintyre project for US$ 495 million, with Cameco (70%). In February 2009 Mega Uranium sold 35% of the Lake Maitland project to the Itochu Corporation (10% of Japanese share) and Japan Australia Uranium Resources Development Co. Ltd. (JAURD), acting on behalf of Kansai Electric Power Company (50%), Kyushu Electric Power Company (25%) and Shikoku Electric Power Company (15%) for US$ 49 million.

In Namibia, Itochu Corporatioon bought a 15% stake in Kalahari Minerals, in March 2010, for US$ 92 million. Kalahari owns 41% of Extract Resources, which is developing the Husab project. Then in July 2010 Itochu bought a 10.3% direct stake in Extract for US$ 153 million, mostly from Polo Resources, giving it 16.43% overall in the project.

Fuel cycle – front end

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 had seven cascades each of 150,000 SWU/yr, though only one has been operating.   It has been testing a lead cascade of its new Shingata design, and is re-equiping the plant with this, to come on line in September 2011. The plant’s eventual capacity is planned to be 1.5 million SWU/yr by about 2020.  JNFL’s shareholders are the power utilities.

A new enrichment plant in Japan using Russian centrifuge technology is planned under an agreement between Rosatom and Toshiba.

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 440 tU/yr fuel fabrication facility, which started up in 1972 and has had majority shareholding by Mitsubishi Materials Corporation (MMC).  In April 2009 this was restructured as a comprehensive nuclear fuel fabrication company to supply Japanese customers with uranium fuel assemblies for pressurized water reactors (PWR), boiling water reactors (BWR) and high-temperature gas-cooled reactors (HTR), as well as MOX fuel assemblies.  It will also provide related services, including uranium reconversion from 2014.  The new shareholdings are MHI 35%, MMC 30%, Areva 30% and Mitsubishi Corporation 5%, with capital of JPY 11.4 billion.  In October it was announced that a new 600 t/yr plant using Areva’s dry process technology would be built by the company.  As part of the new partnership with Areva, MHI and Areva are preparing to build a dedicated nuclear fuel fabrication facility in the USA, with each having 50% equity.

At Kumatori and Tokai, Nuclear Fuel Industries (NFI) operates two fuel fabrication plants which have operated from 1976 and 1980 respectively.  Kumatori (284 tU/yr) produces PWR and BWR fuel, Tokai (200 tU/yr capacity) is also set up to produce HTR and FNR fuel.  NFI is also involved in a project to design MOX fuel for Areva to manufacture for Japanese power plants.  In 2009 Westinghouse bought the 52% share of NFI owned by Furukawa and Sumitomo for $100 million.

JAEA has some experimental mixed oxide (MOX) fuel fabrication facilities at Tokai for both the Fugen ATR and the FBR program, with capacity about 10 t/yr for each.

Fuel cycle – back end

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).

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 processed over 1000 tonnes of used fuel, with a Pu-U mixed product. The plant 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 operated 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.

Until a full-scale plant was ready in Japan, the reprocessing of used 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 commercial operation of JNFL’s reprocessing plant at Rokkasho-mura was scheduled to start in 2008. Used fuel has been accumulating there since 1999 in anticipation of its full-scale operation (shipments to Europe finished in 1998).

Reprocessing involves the conventional Purex process, but Toshiba is developing a hybrid technology using this as stage 1 to separate most uranium, followed by an electrometallurgical process to give two streams: actinides (plutonium and minor actinides) as fast reactor fuel, and fission products for disposal.

Rokkasho complex – reprocessing and wastes

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 (used fuel) 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.  The used fuel storage capacity is 20,400 tonnes.

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 JPY 2.4 trillion (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 confirmation of the joint industry-government formulation of nuclear policy for the next several decades.*

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.

The Rokkasho-mura reprocessing plant was due to start commercial operation in November 2008, following a 28 month test phase plus some delay at the end of 13 years construction. The intended date is now October 2012, the ongoing delay being due to problems in the locally-designed vitrification plant for HLW at the end of the line (see below).  The main plant 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 was expected to reprocess 395 tonnes of used fuel, from which it will recover 1.9 tonnes of fissile plutonium (in reactor-grade material).  In FY 2009 about 160 tonnes of fresh used fuel is expected to be reprocessed, yielding 0.9 t fissile plutonium (Puf), and apparently 425 tonnes of stored fuel, to recover an additional 2.3 t Puf.

Active testing at the new vitrification plant attached to the Rokkasho reprocessing plant commenced in November 2007, with separated high-level wastes being combined with borosilicate glass.  The plant takes wastes after uranium and plutonium are recovered from used fuel for recycle, leaving 3% of the used fuel as high-level radioactive waste.  However, the furnaces (developed at Tokai, rather than being part of the French technology) have proved unable to cope with impurities in the wastes, and commissioning is much delayed.  Finally in 2010 JNFL decided to redesign the unit to better control temperature of the molten glass, resulting in a delay to October 2012 for commissioning.

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, enough for about 80 tonnes of MOX fuel.

Mutsu storage

In 2010 Recyclable-Fuel Storage Co obtained approval to construct a facility at Mutsu in Aomori prefecture to store used fuel from Tepco and Japco nuclear plants for some 50 years before reprocessing at the Japan Nuclear Fuel plant. It is expected to take 3000 t/yr. Construction started in July 2010 and is due to be completed by 2012.

Mixed-oxide fuel (MOX)

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 2015 under the “pluthermal” program. About 6 tonnes of fissile plutonium per year (in about 9 tonnes of reactor-grade Pu) 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 has slowed implementation of the 1994 “pluthermal” program, and not until late 2009 was there a commercial Japanese reactor running with MOX.

By end of January 2010 the Nuclear & Industrial Safety Agency (NISA) on behalf of the Ministry (METI) had approved the use of MOX fuel in ten reactors, including: Takahama 3 & 4, Fukishima I-3, Kashiwazaki Kariwa 3, Genkai 3, Hamaoka 4, Onagawa 3 and Shimane-2.  This is expected to occur progressively to 2012, after modifications to the reactors to take a one quarter or one third core of MOX.  NISA permission for MOX use in Tomari 3 is pending.

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 accepted Kansai’s planned use of MOX at Takahama-3 and 4 from 2010, and Hokkaido accepted Hokkaido Electric Power’s use of MOX at Tomari-3, making a total of 11 reactors allowed to use it.  Early in 2010 Fukushima prefecture agreed to MOX use in TEPCO’s Fukushima I-3 reactor, and in July NISA confirmed this approval.

So far, Japan has received five shipments containing over two 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.

Subsequent shipments have been in the form of MOX fuel for light water reactors. The first MOX shipment 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, so that material was returned to the UK in 2002. The balance was for Tepco’s Fukishima I-3. The second MOX shipment consisted of fuel from BNFL for use in TEPCO’s Kashiwazaki-Kariwa-3 reactor. The third MOX shipment was fuel for Chubu’s Hamaoka BWR, Shikoku’s Ikata PWR and Kyushu’s Genkai PWR, and arrived from France in May 2009. The fourth MOX shipment in 2010 from France contained 12 assemblies for Kansai’s Takahama-4 and 20 for the second load at Genkai-3.

In November 2009 Kyushu Electric Power started using MOX in its Genkai-3 reactor. During a scheduled refuelling outage the company replaced about one-third of the 193 PWR fuel assemblies, 16 of them comprising MOX fuel. Shikoku Electric Power Co started Ikata-3 with some MOX fuel in March 2010, and Tepco started up Fukishima-Daiichi-3 BWR with MOX fuel in September 2010.  Kansai started using MOX in its Takahama-3 PWR in January 2011.

For its new Ohma ABWR plant, designed to run on a full MOX core, J-Power has signed a contract with Areva to supply the first three years’ fuel, fabricated from Japanese plutonium separated in France.  Areva also has MOX fabrication contracts with Chubu, Kyushu, Shikoku and Kansai.

Meanwhile, Japan’s plutonium stocks increase, with separated reactor-grade plutonium (about 65% fissile) stored and awaiting use in MOX fuel.  At the end of 2008 there was 25.2 tonnes of fissile plutonium (Puf) held by Japanese utilities overseas: 13.8 t in France and 11.4 t in UK, plus 6.6 t Puf (9.7 t Pu total) held domestically by JAEA and JNFL.  At the end of 2009 there was 10.06 tonnes Pu stored in Japan and 24.13 t stored overseas. During 2009 1.345 t Pu was loaded into Japanese reactors in MOX fuel and 1.72 t was added to storage. It is estimated that 5.5 to 6.5 tonnes of Puf will be used each year from about 2012.

J-MOX plant

In April 2005 the Aomori prefecture approved construction of the J-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 the plant started in October 2010 after a three-year delay due to revision of seismic criteria. Operation of J-MOX is now expected about March 2016, and the cost has escalated to JPY 190 billion (US$ 2.4 billion).

In November 2006 Shikoku Electric Power contracted with Mitsubishi to manufacture 21 MOX fuel assemblies for its Ikata nuclear plant using 600 kg of reactor-grade plutonium. The plutonium had been recovered by Areva at La Hague from Shikoku’s used fuel and the MOX was fabricated at Areva’s Melox plant in France and shipped to Japan in March 2009.

With the delay in construction of the J-MOX plant, several other utilities have sought MOX fuel supplies from Areva in France.

Once MOX fuel is fully in routine use in Japan, it is expected that the Japanese stockpile of separated plutonium in Europe will be used up in about 15 years, with demand being about 6 tonnes per year of fissile plutonium and output from Rokkasho only 4 tonnes Puf.

METI approved construction a used fuel storage facility for Tepco and Japco in Mutsu, at the same time as approving J-MOX. Government approval for both followed in May

Fast Neutron 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.  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 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 (electrometallurgical refining). 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 JPY 34.6 billion.

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). 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. From July 2007 Mitsubishi FBR Systems has operated 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 Vitrified Waste Storage Centre. 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, making a total of 1310 canisters. Shipments from UK started in 2010, with 1850 canisters to go in about 11 shipments.  These include an equivalent amount of HLW to avoid the need to transport greater amounts of low-level wastes (LLW). The first shipment arrived in March 2010.

In 2005 Tepco and JAPC announced that a Recyclable Fuel Storage Centre would be established in Mutsu, operating from mid 2012 with 5000 t capacity. The JPY 100 billion facility will provide interim storage for up to 50 years before used fuel is reprocessed.  NISA approved this in August 2010.

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 JPY 3000 billion (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 JPY 19 trillion, 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 were to be transferred to it and companies then refunded as required for reprocessing.

METI, with JNFL and FEPC, is seeking permission from the Aomori prefecture to build a low-level waste storage facility at Rokkasho. In particular this will be for LLW returned from France from 2013.

Decommissioning

The Japan Power Demonstration Reactor (JPDR) decommissioning program, following its closure in 1976, established the necessary techniques for the decommissioning of commercial power reactors by the Japan Atomic Energy Research Institute (JAERI). Phase I of the program started in 1981 to develop a set of techniques and Phase II was actual dismantling of JPDR over 1986-92.

The original Tokai-1 power station, a British Magnox reactor which started up at the end of 1965 and closed down in March 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 are being 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 is expected to be JPY 93 billion – 35 billion for dismantling and JPY 58 billion for waste treatment including the graphite moderator (which escalates the cost significantly).

Fugen ATR (148 MWe, started up in 1978) closed in March 2003, and JAEA plans to decommission it and demolish to clear the site by 2029, at a total cost of about JPY 70 billion, including waste treatment and disposal.  Plans for this were approved in February 2008.

Chubu’s Hamaoka 1 & 2, earlier closed for safety-related upgrades, remained shut down following the 2007 earthquake, were written off, and are now being decommissioned.

In March 2011 units 1-4 of the Fukushima Daiichi plant (2719 MWe net) were seriously damaged in a major accident, and appear certain to be written off and decommissioned.

Japanese reactors decommissioned

Reactor Type Net capacity MWe Utility Commercial operation
JPDR BWR 12 JAERI 2/65 – 3/76
Tokai 1 Magnox 137 Japco 7/66 – 3/98
Fugen ATR 148 JNC 3/79 – 3/03
Hamaoka 1 BWR 515 Chubu 3/76 – 2/09
Hamaoka 2 BWR 806 Chubu 11/78 – 2/09
Fukushima I-1 BWR 439 Tepco 3/71 – 3/11
Fukushima I-2 BWR 760 Tepco 7/74 – 3/11
Fukushima I-3 BWR 760 Tepco 3/76 – 3/11
Fukushima I-4 BWR 760 Tepco 10/78 – 3/11

JAEA is responsible for research on reactor decommissioning.

Research & Development

The Japan Atomic Energy Research Institute (JAERI) and the Atomic Fuel Corporation were set up in 1956. The latter was renamed PNC in 1967 and reconstituted as Japan Nuclear Cycle Development Institute (JNC) in 1998. 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 JPY 161 billion (US$ 1.7 billion).

At the end of 1998 JAEA’s small prototype gas cooled reactor, the 30 MWt High Temperature Engineering Test Reactor (HTTR) started up at the Oarai R&D Centre. 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.

JAEA’s Japan Materials Testing Reactor (JMTR) at the Oarai R&D Centre is being refurbished for 2011 resumption of operation, when it will produce some radioisotopes, notably Mo-99, as well as enable basic research on LWR fuel and materials, and other applications.  The JMTR was initially converted from 93% HEU fuel to 45% enriched fuel in 1991, and then to 19.8% enriched fuel in 1994.

The Reduced-Moderation Water Reactor (RMWR) being developed in Japan is a light water reactor, essentially as used today, with the fuel packed in more tightly to reduce the moderating effect of the water. Considering the BWR variant (resource-renewable BWR – RBWR), only the fuel assemblies and control rods are different. In particular, the fuel assemblies are much shorter, so that they can still be cooled adequately. Ideally they are hexagonal, with Y-shaped control rods. The reduced moderation means that more fissile plutonium is produced and the breeding ratio is around 1 (instead of about 0.6), and much more of the U-238 is converted to Pu-239 and then burned than in a conventional reactor. Burn-up is about 45 GWd/t, with a long cycle. Initial seed (all??) MOX fuel needs to have about 10% Pu. The void reactivity is negative, as in conventional LWR. A Hitachi RBWR design based on the ABWR-II has the central part of each fuel assembly (about 80% of it) with MOX fuel rods and the periphery uranium oxide. In the MOX part, minor actinides are burned as well as recycled plutonium.

The main rationale for RMWRs is extending the world’s uranium resource and providing a bridge to widespread use of fast neutron reactors. Recycled plutonium should be used preferentially in RMWRs rather than as MOX in conventional LWRs, and multiple recycling of plutonium is possible. JAERI started the research on RMWRs in 1997 and then collaborated in the conceptual design study with the Japan Atomic Power Company (JAPCO) in 1998. Hitachi has also been closely involved.

A new reprocessing technology is part of the RMWR concept. This is the fluoride volatility process, developed in 1980s, and is coupled with solvent extraction for plutonium to give Hitachi’s Fluorex process. In this, 90-92% of the uranium in the used fuel is volatalised as UF6, then purified for enrichment or storage. The residual is put through a Purex circuit which separates fission products and minor actinides as HLW, leaving the unseparated U-Pu mix (about 4:1) to be made into MOX fuel.

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 (NSC) 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 since the 1990s due to a series of accidents and scandals. The accidents were the 1996 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 (NSC) 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 JPY 200 billion (US$ 1.9 billion).

In 2007 NISA ordered reactor owners to check their records for incidents which should have been reported at the time but were not. This revealed a brief (15 minute) criticality incident during refuelling at Hokuriku’s Shika-1 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 had entailed excavation in some places to 45 metres.

In October 2008 NISA presented to the 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.  In 2009 the NSC endorsed NISA’s recommendation that units 6 & 7 be restarted.

Tsunamis are also a feature of Japan and Kuril Islands. Since 1498 there have been 16 tsunamis with maximum amplitudes above 10 metres (some much more), these having arisen from earthquakes of magnitude 7.4 to 9.0, on average one every 30 years.

A new inspection system of nuclear facilities came into effect in 2009, following deliberations on the matter since November 2005. Under the new system, the number of nuclear power plants approved for operation over 40 years can be expected to increase, starting with Tsuruga-1.

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.

In heavy manufacturing, particularly of large forgings, Japan Steel Works is generally regarded as the world leader. Other enterprises are also active in export of major reactor components.

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.

This led in 2009 to an industry-based group, the JAIF International Cooperation Center (JICC), established with government backing to support countries planning to introduce nuclear power generation, and the International Nuclear Energy Cooperation Council, a forum for the relevant Japanese government authorities and private institutes to collaborate in international aid.

In October 2010 industry and government set up the International Nuclear Energy Development of Japan Co Ltd (JINED) to export nuclear goods and services collaboratively. The new company will solicit orders for nuclear power plants from countries such as Vietnam starting their own nuclear power programs, and advise on project and infrastructure development, bolstered by legislative and financing support from the Japanese Government. A separate company will be set up to act as engineering, procurement and construction (EPC) contractor. The main company, associated with JAIF and JICC, is owned by the government (METI, through Innovation Network Corporation), nine utilities (Chubu, Kansai and Tepco being main shareholders), and three manufacturers (Mitsubishi Heavy Industries, Toshiba and Hitachi).

For Vietnam’s second nuclear power plant, METI said that Japan Atomic Power Co. and JINED would work with Electricity of Vietnam (EVN) on the project.

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.

Source: www.World-Nuclear.org

References:
OECD/NEA 1995, Japan
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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