back to radiation | rat haus | Index | Search | tree

( ASCII text format )

The following is mirrored with the permission of Earthlife Africa from its source at:

An introduction to the
Pebble Bed Modular Reactor (PBMR) programme

From the perspective of the Earthlife Africa Campaign of the Johannesburg and Cape Town branches

Nuclear Energy Costs the Earth
Contents: page 1:

What is the PBMR programme?
What is a Pebble Bed Modular Reactor?
Do we need PBMR?
Export potential?

Contents: page 2 :

Nuclear Power and Climate Change
Policy and Process
Renewable Energy & Socio-economic considerations
Additional material


Earthlife Africa (ELA) has, as part of a wide range of activities, campaigned against nuclear power and weapons since being founded over ten years ago. Recently Johannesburg and Cape Town branches have focused on the squandering of public money on development of a 'new' generation of reactors.

The Pebble Bed Modular Reactor programme (PBMR) within Eskom not only enjoys the benefits of a history of intensive state subsidy for nuclear power, as part of the apartheid governments weapons programme, but also of continuing disproportionate funding allocations, a lack of coherent energy policy and questionable application of law. The solar and wind energy resources available in South Africa are sufficient to provide for all our energy needs many times over. The development of new nuclear power plants is unjustifiable on any terms, but particularly when judged as an energy strategy for South Africa, rather than solely as a speculative investment opportunity. The PBMR programme is designed to capitalise on previous subsidisation and an energy industry that continues to ignore full social and environmental costs of energy generation, such as impacts on human health and the environment.

Proponents also misrepresent the possible role of nuclear power in climate change mitigation. Eskom chooses to talk publicly only of the initial "reference module" that they are trying to push through, yet the projected foreign exchange and employment benefits that are used to gain political support are based on the production of at least 216 reactors, including 11 for local use, "by the year 2016" (Ref 1) Possibly 30 more export units in that year have also been factored in. In an earlier article programme manager David Nicholls in Nuclear Engineering International suggested a third of all units would be for local construction.

Ref.1 - Official letter from Eskom PBMR programme, to ELA, August 1999
What is the PBMR programme?

This depends on who is asked and who is asking, variously:

  • a study; a reckless gamble;
  • the most promising avenue, internationally, for the nuclear industry to retain a stake in the energy market; a major obstacle to sustainable development;
  • a bid by special interests to achieve job security . . .

The following is an extract from the Eskom website:

One of the areas that is being investigated under this [Integrated Electricity Planning ] programme is a nuclear power technology based on German work with High Temperature Gas-cooled Reactors (HTGR) from the 1960s to the 1980s. In order to evaluate this option Eskom has identified a variant of this reactor type called a Pebble Bed Modular Reactor (PBMR) to generate the technical and commercial data for the study.

It is deceptive to refer to the current activities as a "study" - Eskom themselves admit to having spent over R90 million, by the end of 1999, on this project. We have not been able to ascertain whether this includes the many international sales / promotion trips, which presuppose a positive outcome from a supposedly objective process to determine the desirability of pursuing this contested option. The total cost of starting the first "reference module" reactor was anticipated, by the proponents, to be in excess of R 1 300 million:

  • "Future total cost estimates":
  • Total Development Cost: R 442,5 Million;
  • [plus] Fuel Plant Capital: R87,4 Million;
  • [plus] Power Plant Capital: R 688,0 Million;

    Please note that the precise allocation of costs to development versus capital, as shown above, is still to some extent under debate within our organisation. Also please note that the above expenditures and estimates are based on 1999 Rands and do not include for CPA (future inflation), Interest During Construction, cost of Forex Cover [mandatory] and possible PBMR Company overheads during construction of the Reference Module." (Ref.1)

Eskom declines to give a breakdown of its spending according to the energy source (or `carrier'), either in the area of research and development or of project spending. However it is clear that nuclear alone is receiving more financial support than all renewable energy sources combined (we subscribe to a growing body of opinion that does not consider large dams to be a renewable resource). The proponents are playing on government's desire to capitalise on past investment (as in the White Paper Ref. 2) to justify throwing good money after bad and to pre-empt inclusive and balanced consideration of alternatives.

Timing estimates for the programme have varied since the programme was initiated in 1993 but the most recent estimate on record appears to be: "Building of the plant is planned to start in 2001 while cold and hot operation of the plant is planned for 2003 and 2004." Ref. 3 [Hot operation is when the nuclear reaction reaches the level at which electricity supply may start.]

Ref 2 - White Paper on Energy Policy for RSA (
Ref 3 - Tony Stott at a meeting with Cape Metropolitan Council, 15/11/99


What is a Pebble Bed Modular Reactor?

From the Eskom website:

The PBMR, being purpose-designed for electricity generation, is inherently different from the Pressurised Water Reactor (PWR), the most common type in the world today [e.g. Koeberg]. It uses helium (a gas) to cool the reactor core and drive the turbines. The fuel is based on a ceramic coating of very small enriched uranium dioxide fuel particles (silicon carbide coated particles of less than 1 mm diameter) embedded in a graphite matrix. The fuel is proof against damage up to 1 600 degrees C and will not melt below 3,500 degrees C. The net result is a design which, if the unit is kept below a certain size (about 100 MW), cannot exceed the temperature where fuel damage and radioactive release could occur, even with no external cooling. The plant is therefore considered inherently or "walk away" safe. This limits the size of the plant but avoids the need for highly reliable, diverse and redundant safety systems that are used to ensure adequate safety on current reactor designs.

The fuel-bearing graphite balls would circulate through the reactor core in a so-called `pebble-bed' system. 100MW(megawatts) is about one tenth of the capacity of one of Koeberg's two reactors, which together generate less than 5% of South Africa's electricity.

It is anticipated that power stations will consist of clusters of 5 to 10 reactors - hence the term `modular'. The relatively low power density of a gas-cooled reactor and the small scale are factors that will tend to drive up the cost of the PBMR.

Eskom hope that the relative simplicity of the design and the modularity of the system will allow for the realisation of the economies of mass production. For units following the reference module, under mass production conditions, Eskom's own estimations of costs per kilowatt hour vary from 1.7 to 2.43 US cents. (Ref 4) Analysts at Massachusetts Institute of Technology's Nuclear Engineering Department estimate the cost to be 4.27 US cents , using the same assumed capacity factor and annual capital charge [the "discount rate" by which the programme effectively borrows at only 6% interest].

According to the MIT study Eskom is targeting a capital cost of $1000/kW for a 10 module plant, which would translate into $100 million per reactor unit - this target, equivalent to over R600 million, is slightly less ambitious than the figure of R400 million used by Eskom in local presentations.

An account of the history of HTGRs and why the USA, the UK and the Germans, from whom Eskom procured designs, abandoned attempted applications, has been written by S. Thomas of Sussex University.
In relation to the last operational reactor of this type in Germany he writes: ". . . the plant remained closed on the orders of the safety regulator because of concerns about safety and the unwillingness of the various owners of the plant, including the federal government, to continue to provide subsidies to operate the plant. In 1990, the plant was permanently closed and is being decommissioned."

Anticipated commercial structure of PBMR (Ref.1): "Four separate companies are in the process of being formed, as follows:

  • PBMR Holding Company, which will be a holding company for the following three additional companies
    • PBMR TechCo, the company creating the plant designs
    • PBMR FuelCo, the company manufacturing the PBMR fuel
    • PBMR PlantCo, the company erecting the plant in accordance with TechCo's designs,

with the real internal rate of return for the respective companies being as follows:

    • PBMR TechCo: 15 %;
    • PBMR FuelCo: 37 %;
    • PBMR PlantCo: 29 %.

Ref 4 - A. C. Kadak, The Politically Correct Reactor, Nuclear Engineering Dept. MIT, 1999

The extravagant claims of possible national benefits in foreign exchange and employment are based on a desk-top input-output analysis of a base case scenario, in the absence of meaningful socio-economic analysis. All other arguments put forward to justify the nuclear programme are backward-looking, of the less-bad-than-previously variety, that seek to avoid comparison with the obvious attractions of renewable energy.

Many of these attractions are so simple and untechnical (e.g. wind and sunlight are free) that many `experts' and technocrats manage to ignore them. Furthermore in the current artificially imbalanced energy industry most of the advantages of renewably sourced energy do not translate into capital return on investment.

The emissions from coal-fired power stations are appalling, the impacts on worker health in the mines is unacceptable, the enormous transmission distances of the South African grid are undesirable . . . but no litany of the problems of present practice, that nuclear apologists so readily produce, can of itself justify the use of nuclear power or support for this programme. The same applies to advances in reactor safety and efficiency over previous reactors, even if all the claims are borne out. That a project promises to have advantages over previous practice does not mean that it is the best choice for the future.



By focusing on a relative reduction of risks associated with reactor design and of the magnitude of waste produced, proponents gloss over ongoing problems and impacts of the entire nuclear fuel chain, including uranium mining and enrichment (whereby it is made more radioactive), fuel production, handling and transport and long-term storage of fuel that is spent, i.e. at the end of its useful life.

Indeed, there have been problems in the past with particle design and manufacturing, leading to release of radioactivity from the particles.

According to Eskom work is already underway on producing the fuel in South Africa. The nuclear industry perpetuates the myth that there is such a thing as a "safe" radiation dose, based on its contention that evidence of direct links between low levels of exposure and health effects is not absolutely conclusive. This despite extensive and growing evidence from scientists such as Rosalie Bertell (Ref 5).

The claiming of benefit-of-the-doubt for polluters is inconsistent with the precautionary principle enshrined in our national legislation. The observation that certain kinds of radioactivity occur naturally does nothing to justify creating new sources of radioactivity.

Internationally there is still no accepted method for disposal of long-lived highly radioactive waste, although there is growing consensus that the most responsible strategy is monitored storage above ground, where the integrity of containers is easily checked. These wastes will always pose a risk to future generations.

Also, it would not be impossible to make an atomic weapon from the 5% or more of Plutonium 238 that the high burn-up rate would produce in spent fuel.

Ref 5 - Rosalie Bertell, PhD, GNSH, (President of the International Institute of Concern for Public Health & Editor in Chief of International Perspectives in Public health), The Ecologist Vol.9 No.7

Do we need the PBMR?

Estimation of future electricity demand is an uncertain affair and Eskom's predictions of when demand will exceed supply have been revised over recent years, from 2005 to 2010 and possibly beyond.

South Africa's present generation capacity is almost 40 000 MW, yet the highest peak demand to date was 28 300MW.

While the rate of economic growth is a significant variable, the nature of that growth will also be decisive and the actual timing of a need for greater generation capacity will depend largely on the extent to which current wasteful practices are perpetuated.

Even given hoped-for economic growth, energy efficiency programmes could considerably defer the need for new generation capacity. Eskom themselves dropped their energy use by 34% from 1991 to 1997 at their MegaWatt Park headquarters by using Demand Side Management (DSM) (Ref 6) -- i.e. efficiency measures. Despite extensive overseas precedents showing that efficiency measures reducing use by 20 to 35 % can be achieved at negative cost (i.e. also saving money) , particularly in industry, Eskom's DSM efforts are directed primarily at domestic consumers and the research budget for the field in 1999 was a paltry R10.7million.

Ref 6 - Daily News June 4, 1999.

Export potential?

Critical to the motivation and success of the programme is a market for the export units but while proponents claim that ". . . interest is already being shown by a number of countries including the U.K., China, Indonesia, Morocco, Egypt and Tunisia."(Ref.1), there are no committed customers.

Furthermore it seems safe to assume that if they can persuade any party to sign a letter of intent to purchase, it will contain preconditions relating to the projections of proponents being borne out in practice. The majority of nuclear power projects have a history of actual costs and lead-times (time for development) far exceeding original projections, sometimes more than doubling.

In the USA no new plants have been built for over 20 years and all 41 existing orders have been cancelled since 1974. Japan has recently lost much enthusiasm for nuclear power, not least due to a number of accidents. China has indicated that it will only pursue nuclear power if it can be subsidised through mechanisms under the United Nations Framework Convention on Climate Change.

As the history of cost and lead-time over-runs, the full extent of impacts on human and ecological health, the inadequacy of regulations, safety procedures and risk assessments and the impossibility of determining a `safe' level of radiation exposure are becoming more widely recognised, the market for new nuclear power is unlikely to improve. (See S. Thomas for more detail)

Next page >>

back to radiation | rat haus | Index | Search