With global warming, increasing energy demand and security of supply concerns it is no wonder there is much talk of a nuclear renaissance. PEi reports the latest developments of the South African Pebble Bed Modular Reactor project.

David Flin and Robin Rowshangohar

Much of the world switched the lights off on nuclear power generation 20 years ago, leaving it tightly tucked up in extensive legislation that put off most from rousing it from its slumber to face another morning refreshed and raring to go. It has been a long 20 years and now, as power players prepare to wake up to the increasingly louder calls for a nuclear comeback, one company plans to lead the market with a nuclear energy product that will take more than a stream of red tape to tire.

South Africa’s Pebble Bed Modular Reactor (PBMR) Company is confident that it is at the forefront of developments, with firm orders from its national government for some 4000 MW of PBMR capacity. Hoping to build on this momentum, the company, supported by the UK’s Nuclear Industry Association, decided to host a one-day conference in London to outline progress on the project.

January was indeed an excellent time to be holding the conference, as issues of climate change were regularly hitting the headlines, and the UK government had just announced that it would be preparing a new energy review. With major uncertainties over the price and security of supply of gas, especially from Russia at the time of the conference, there wasn’t a better time or place to be discussing the next generation of nuclear reactors.

Causing a sensation

The South African government was clear and categorical in its support for the project, lending confidence to the viability of the project. One aspect that was of particular interest to the South African government was that the PBMR project would provide work in key areas of the economy, and that it would make use of nuclear skills within the country helping to develop these skills still further. From a domestic demand point of view the South African government also took account of the geography of the country, with most of the coal reserves in the north far from the coast, and significant growth in power demand on the coast. South Africa also has large reserves of uranium, making the case for the nuclear option quite compelling and it is easy to understand why the government has already placed an order for 24 reactors.

The main power system as contained within the citadel
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PBMR said it was this initial order that had made the project economically viable. It enables it to justify a fully commercial fuel supply and maintenance support organizations. It will also bring the large component cost within a manageable range. The order from the government has enabled PBMR to begin construction of a pilot fuel plant in Pelindaba. The project is designed to prove that fuel manufacturing is sustainable on an industrial scale. A crucial second phase of this development has recently been contracted to Thermtron Projects, a South African design house, which will design the coated particle production facility.

With the project given credence with the supporting infrastructure currently being put in place, conference attendees were more eager to note the two features being specifically highlighted as attractive selling points of the PBMR:

  • Modularity
  • Process heat applications.

The modularity makes the PBMR suitable for use in developing countries, where grid networks may be unable to sustain large central power of 1000 MW. Modules can be added as appropriate, enabling development of the grid to proceed in tandem with development of generation capacity. Big target markets for this application are considered to include Brazil, China and India. Modular units also provide greater operational flexibility, and are better able to balance supply and demand.

Another positive selling feature presented by PBMR for the reactor is the fact that the modules are relatively small in size and can be used to replace the very early commercial reactors that are now being decommissioned or have been decommissioned. For example, the Magnox reactors in the UK are at such a stage of their life that the UK is having to address the question as to what will replace these units. The PBMR reactors offer one possible solution to that question. According to the company, the smaller size also allows for more rapid construction times and greater benefits from economies of scale.

Not so cold

Perhaps less immediately obvious as an advantage of the PBMR is its high temperature operation, enabling it to be used to provide process heat or steam for large industrial applications. This makes it a cogeneration application, and while it is unusual, to say the least, to discuss nuclear cogeneration plants, that is exactly what is being offered. The pilot plant is set to produce 165 MW of electricity and 400 MW of thermal energy through its helium cooled reactor with direct cycle high temperature gas turbine. There are a number of applications where this process heat could be useful, including:

  • Hydrogen production. Producing hydrogen from fossil fuels does nothing to reduce CO2 emissions and protect the environment
  • Producing syngas from natural gas
  • Oil sands recovery and processing
  • Cogeneration at large refineries and petrochemical plants
  • Converting coal to liquid fuel.

The main drivers in these markets are the cost of natural gas and petroleum, the desire for energy security and diversity, the elimination or reduction of CO2 emissions, and meeting the growth in energy demand.

Safe and sound

Safety is a key issue for any nuclear power plant that wishes to be part of the next generation. As the world prepares to remember the 20th anniversary of the Chernobyl nuclear disaster, the industry and the possible consequences of its use will come under increased scrutiny. This could work to PBMR’s advantage, however, as it has recently invited and welcomed a multi-national team under the leadership of the International Atomic Energy Agency to conduct an independent review of its safety culture. In late February and early March up to 250 randomly selected PBMR team members were interviewed with the aim of measuring the set up against world best practice and highlighting areas for improvement. With no active system for emergency shutdown the company maintains that the PBMR product is inherently safe and as such it has a small safety zone enabling it to be sited close to the point of use.

Most Generation IV reactors are due to be commercially available by 2030; the PBMR is likely to be more than a decade in advance of this. The first commercial unit is due to be in commercial operation by 2014.

Fuel element design for the PBMR
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Construction of the pilot plant will begin in September 2007 at a site near South Africa’s only existing nuclear power station, Koeberg on the Western Cape. The project will also see the development of a helium test facility and a heat transfer test facility. Full fuel loading is expected to take place exactly three years after construction starts in September 2010 and the plant will be handed over to South Africa’s state owned utility, Eskom a year later in 2011.

The current shareholders, South Africa’s government, the International Development Council and Westinghouse, which acquired the 15 per cent holding of British Nuclear Fuels Ltd in March this year, are confident that there product will enjoy the benefits that being “first to market” will bring. When it enters commercial production as a product by 2014 at the latest, the PBMR Company expect to be able to deliver six units per year, three of which will be sold to Eskom and three of which will be available to the international market.

When the PBMR enters operation it will be the first fourth generation nuclear energy reactor the world has seen and it should at least make the world sit up and ponder a new day, not reach for the snooze button and drift off into another dream about an ideal solution.

PBMR timescale

1990: Germany decides to discontinue work into High Temperature Reactor (HTR) development. Memorandum of Understanding for technology transfer agreed in September between Germany and South Africa.
1993/4: The South African utility Eskom starts a small R&D project with a budget of a “few thousand Rand”. Secured technology licence.
2000: Detailed feasibility study starts.
2001: The South African government decides to support the project. PBMR Ltd forms to make it a commercial reality.
2002: Detailed feasibility study completed.
2004: South African Minister of Public Enterprises, Alec Erwin, states the government’s intention to produce 4000-5000 MW of power from PBMRs in South Africa.
2005: Business plan developed for commercial units. Contracts with all major suppliers in place. PBMR major design finalised.
2006: Environmental Record of Decision due.
2007: Site construction of pilot project to start.
2014: First commercial units available, with Eskom buying three units per year.
2016: Export of first units. PBMR plans to sell six units per year.