Wednesday, November 17, 2010

Flipping on the nuclear power switch in Singapore

Nov 17, 2010
By Seeram Ramakrishna

WHILE delivering the Singapore Energy Lecture during the annual Singapore International Energy Week recently, Prime Minister Lee Hsien Loong said that nuclear power is a clean source of energy and Singapore cannot afford to dismiss the option of nuclear energy. When a member of the audience pressed him for a definite timeframe for Singapore to consider building a nuclear power plant, he quipped: 'I would say possibly during my lifetime.'

Nuclear experts from around the world, who are observing developments in the region, said that these were wise words for the following reasons:

Opting for a nuclear power plant is a long-term commitment - a 100-years decision, in fact. A typical nuclear power plant is designed to generate electricity for six to eight decades; the time needed to build, commission and decommission a nuclear reactor spans a few decades.

Countries that have harnessed nuclear energy successfully tend to meet 20-40 per cent of their respective national electricity needs from nuclear power, with the remainder from diversified energy sources including coal, natural gas, hydro, solar and wind.

Singapore's electricity need is in the range of 6,000 megawatt electrical (MWe) to 6,500MWe, and is expected to grow by 2-4 per cent annually. Going by the experience of other countries, Singapore may consider harnessing nuclear energy approximately in the range of 1,000MWe to 2,500MWe.

Over the years, the capacity of a single nuclear power reactor has increased substantially, so it is possible to benefit from the economies of scale. For instance, the most recent European Pressurised Reactor (EPR) has an electrical power output of 1,650MWe.

Though a single such reactor may meet Singapore's needs, back-up arrangements would be necessary to take care of the electricity needs during the down time of a nuclear power reactor. Finland is building an EPR in Olkiluoto with significant project delays and cost overruns for a host of reasons. The nuclear industry needs to wait for a few more years to fully assess the price competitiveness of electricity generated from such nuclear power plants.

Given Singapore's relatively modest total electricity needs, it is logical to consider small modular reactors (SMRs), whose capacities range from tens of MWe to few hundreds of MWe.

Nuclear organisations in the United States, South Korea, China, Russia, Japan and India have embarked on SMRs with objectives such as these:

# To meet the electricity needs of off-grid, remote places and smaller cities;

# To lower the upfront substantial financing burden a large reactor would entail;

# To site a nuclear power reactor below the earth's surface;

# To be nuclear-proliferation-resistant;

# To meet the enhanced safety requirements of nuclear regulators and the public; and

# To generate water and hydrogen in addition to electricity.

These features of SMRs would be attractive to Singapore, considering the densely populated and geographically limited nature of the country.

But SMRs are now in different stages of design, analysis, demonstration, and regulatory review and licensing in different countries. It would be realistic to assume that it would take another two to three decades to prove the economic competitiveness and commercial viability of SMRs.

There are other major considerations that new nuclear nations need to consider: among them, the security of the nuclear fuel supply, and the safe management of used reactor fuel.

International discussions are ongoing to provide 'cradle to grave' service for nuclear fuels. In other words, an arrangement will likely emerge for suppliers to take back the used reactor fuel.

Such an arrangement would be desired by several new nuclear nations, since they would have limited scope and abilities to develop their own full nuclear fuel cycle capabilities. However, it would take several years for such a 'cradle to grave' arrangement to emerge and become an accepted international practice.

Taking all this into consideration, it is obvious that what appeared to be a light-hearted quip by PM Lee - 'possibly during my lifetime' - was indeed a realistic assessment.

The writer is vice-president (research strategy) at the National University of Singapore.

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