Japan to steer its own course for Generation-IV reactors

Friday, 12 October 2007 Despite being a member of the Generation-IV International Forum (GIF), Japan is taking its own initiative in developing new reactor designs based on present ones, for deployment about 2020.

The Ministry of Economy, Trade and Industry (METI), the Federation of Electric Power Companies (FEPC) representing eleven utilities and the Japan Electrical Manufacturers' Association - have announced that they would begin full-scale development of next-generation light water reactors (LWRs), as a national project, starting in 2008 and targeted at becoming international standards. Eight years will be needed to complete the basic designs, at a cost of JPY60 billion ($520 million) in combined private and public funds. One BWR design and one PWR design, each with 1700-1800 MWe of electric output, will be developed.

Having worked on feasibility studies for such next-generation LWRs since 2006, the three decided to move to full-scale development, taking into account the increased demand for replacement reactors in Japan that is expected to start around 2030 - which is the GIF timeframe, and expected growth in the world market.

They have agreed that manufacturers - Toshiba, Hitachi-GE and Mitsubishi - should take the initiative in the project and include the next-generation LWRs to be developed in their primary reactor line-ups, while the eleven electric power utilities involved cooperate actively from their positions as principal users. To help this along, the Japanese government will take special actions toward ensuring necessary budgets while developing an environment conducive to international activities.

The major concepts guiding the project include the following:

• The use of at least 5% enriched fuel in reactors (the first time ever in the world) to substantially reduce the amount of used fuel and attain the world's highest availability factor.
• The use of base-isolation technology to enable a standardized plant without regard to site conditions.
• The development of new materials and water chemistry to allow an 80-year plant life and substantially reduce radiation exposure during routine maintenance work.
• Substantially shorter construction periods through the adoption of innovative construction technology.
• The simultaneous realization of the world's highest levels of safety and economy through the optimal combinations of passive and active systems.
• State-of-the-art digitalization of operations, simultaneously improving availability factors and safety.

Atoms in Japan reported that in the period 2008 to 2010 conceptual designs will be addressed and elemental technologies will be developed, in order to assess the feasibility of the plant concepts. The results would then be evaluated by mid-2010, leading to a decision on whether, when and how to take forward the designs into full development.

METI will also develop standards for the new reactors as work proceeds and will liaise with Japan's safety authorities.

In parallel with this, Japan is part of GIF which is developing six reactor technologies which the participants believe represent the future shape of nuclear energy. These are selected on the basis of being clean, safe and cost-effective means of meeting increased energy demands on a sustainable basis, while being resistant to diversion of materials for weapons proliferation and secure from terrorist attacks.

In general the six systems under consideration by GIF are quite different to current mainstream reactors. Most employ a closed fuel cycle to maximise the fuel resources and minimise high-level wastes to be sent to a repository, which is in line with Japan's long-standing policy. Three of the six are fast reactors and one can be built as a fast reactor. Only one GIF system is a light water reactor and an evolutionary development of most of today's Generation-II types.

In February 2005, five of the GIF participants signed an agreement to take forward research and development on the six technologies. Canada, France, Japan, UK and the USA agreed to undertake joint research and exchange technical information.

The new Japanese project seems to be aimed at filling a perceived gap between the third-generation designs now being built and the Generation-IV fast reactor designs which Japan sees as coming into commercial use about 2050. In April 2007 the government designated Mitsubishi Heavy Industries as the lead player in developing a new generations of fast reactors.

A total of eleven utilities will participate in the project, including nine members of FEPC (all except the Okinawa Electric Power Company), plus the Japan Atomic Power Company (Japco) and the Electric Power Development Company (EPDC or J-Power). Participating manufacturers are Toshiba Corporation, Hitachi-GE, and Mitsubishi Heavy Industries. The three parties will establish a consortium-like organization to implement the project, and are now working toward that.

Further information 

WNA's Advanced Nuclear Power Reactors information paper
WNA's Nuclear Power in Japan information paper