28 May 2007 - 09:22
  • News Code: 105721

In October 2006, leading electricity companies from around the world issued a report titled “Powering a Sustainable Future“. They urged governments to start favoring low-carbon sources of electricity like nuclear, solar and wind power.

The members of the International Atomic Energy Agency (IAEA) have already stated their desire to maintain nuclear power as an energy option for the future. This articles focuses on the special type of nuclear reactor known as the Pebble-Bed Modular Reactor (PBMR). To my mind this is more suitable for developing nations.


Types of Reactors

In 1956 the world’s first industrial nuclear power plant was constructed at Colder Hall, in the United Kingdom, that used Gas-cooled Reactors to generate 180 megawatts. The advanced gas-cooled reactors (AGR) was the next version of the Gas-cooled Reactors. Boiling water reactor (BWR) is a simple design that helped to achieve the economic breakthrough in electricity generation in the United States of America. The most common reactor model in operation is Pressurized Water Reactor (PWR). The second most prevalent type is Boiling Water Reactor (BWR). The next reactor type is the Pressurized Heavy Water Reactor .The Graphite Moderated Boiling Reactor is a Russian product that in 1986 faced an accident. Pebble Bed Modular Reactor (PBMR) is another type of modern reactor that gained the attention of the developing nations such as China and South Africa.


Splitting Atoms

Everything around us is made up of atoms. An atom is extremely small and about hundredth of a millionth of a centimeter. Each atom has at its centre a nucleus consisting of protons and neutrons. Electrons orbit the nucleus. Nuclear power is the energy that can be found in the core (nucleus) of an atom. There is a huge energy in the atom that binds all its particles together. By releasing those binding energies of the atoms, nuclear reactors make power. Nuclear reactors split atoms to release those binding energies. This splitting process is known as nuclear fission. The fuel widely used by nuclear reactors to split atoms (nuclear fission) is uranium.



A nuclear reactor is a machine that produces heat in a controlled manner. Its heat makes steam and the steam turns blades of the turbine of the generator to produce electricity. And, here we are discussing the Pebble Bed Modular Reactors (PBMRs), which are becoming popular in the nuclear power industry. Three decades ago, the PBMR was built at Julich Nuclear Research Centre in Germany. But, only recently, it re-emerged as a promising energy outfit. What makes the PMBR technology so special is its safety features that prevent reactors from melting down or exploding like Three-Mile or Chernobyl nuclear plants. The nuclear fuel (uranium) in its spheres cannot become too hot to melt the casing and escape. Other types of reactors use water as a coolant (water contains flammable oxygen). But, PMBR is cooled by helium.


China, South Africa

China heavily relies on eco-unfriendly and unsustainable energy sources--fossil oil and coal. Now using nuclear energy China intends to increase power output from 8 700 to 36 000 megawatts. Therefore, it is planning to produce small commercial Pebble Bed plants (195 megawatts). As a bold step, researchers at the Tsinghua University in collaboration with the Massichte Institute of Technology (USA) is developing an advanced model of Pebble Bed Reactor that is more suitable for developing countries where more villages and small and medium industrial sites are situated in remote areas.

South Africa is the only well established nuclear power in Africa. It has two nuclear reactors at Koeberg nuclear complex. They produce 6% (1 800 megawatts) of the country’s electricity and sell about 200 megawatts to Namibia. Now South Africa has begun to build a 165 megawatt Pebble Bed Modular Reactor at Koeberg.


Clean Energy

Global demand for energy will grow by more than 50% by 2030 and IAEA cautions that the world energy crunch needs innovative and green technological breakthroughs. The Southern African Development Community (SADC) agreed at a meeting in Harare, on April 25 2006, to implement short-term power generation projects that will add 6 700 megawatts to the regional power grid. However, the prevailing climate change on the continent can harm those projects. Dr Kevin Scott, a researcher at the South African Institute for Agricultural Engineering, recently said the following: “We used to have good rains, but the rains are now disappearing. We should expect more droughts.“

Based on these realities, governments should look at nuclear power as a clean and essential tool to power their nations. Even countries such as Brazil, which is blessed with fossil oil reserves, hydropower and alternative fuel with ethanol, has planned to build four nuclear power plants. This means developing nations keep high hopes in clean and sustainable energy sources.



When the global economies grow, all nations will demand more power to run and sustain their households and industries. However, there is a world of energy around us. The challenge is using these energies in a viable way technologically, economically and environmentally. Hence, developing nations can use green and sustainable new power products such as Pebble-Bed Nuclear Reactors to leapfrog their economic growth and reverse the poverty of their people. Monish Gunawardana Windhoek



News Code 105721

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