Nuclear plants: Interesting power option for Singapore

Carlo Vitanza, Julian Kelly & Seeram Ramakrishna, For The Straits Times 16 Jul 10;

LAND-SCARCE and deprived of energy resources, Singapore is constantly on the lookout for the best options to ensure its long-term energy security.

Devoid of energy resources such as coal, oil, gas, hydro, wind, tidal, geothermal and biomass power, Singapore finds its options narrowed down to: enhancing energy efficiency across the spectrum of users, electrification of the transport sector as well as adopting climate-neutral energy sources.

Opting for a mix of energy sources as opposed to relying on a single source makes for a smart energy security strategy. Hence, it is logical for Singapore to consider an energy mix of natural gas, waste-derived energy, solar energy and nuclear energy.

Singapore generates nearly 80 per cent of its electricity from natural gas and a small amount from converting waste.

Singapore has recently focused on solar energy. Within a short span of three years, the country has nurtured solar energy research, as well as nursed a flourishing solar industry, remarkably well. Given its often cloudy conditions and limited space for deploying solar panels, and considering best-performing solar panel technology, Singapore can tap solar energy anywhere in the range of 10 to 20 per cent of its total electricity demand.

Singapore can supplement the above options with nuclear power. Given its situation, nuclear energy poses an interesting option.

Nuclear power plants are known for their ability to supply large amounts of base-load electricity. Japan, South Korea, China and India are pursing nuclear energy successfully.

The key concerns of policymakers and the public are cost competitiveness of nuclear energy, safety and security of a nuclear power plant, and the national approach towards handling long-term hazardous waste in the form of radioactive, spent nuclear fuel.

The economics of nuclear energy is very much dependent on where the power plants are sited and who builds them. Safety and security aspects of a nuclear power plant are extra-sensitive in the case of Singapore as it is a densely populated, geographically small city- state in close proximity to neighbouring countries.

Given Singapore's physical limits, siting small nuclear power units on offshore barges, or even futuristically, inside rock caverns under the seabed, are interesting options.

There are many examples of nuclear power plants using seawater for secondary cooling purposes. We wish to point out that the 20-megawatt OECD Halden nuclear reactor is sited inside a mountain in Norway. The Halden reactor has been operating successfully for five decades - since 1959 - and supplies steam to a paper mill next door. One of the authors of this article has his house on top of this mountain.

The Halden reactor project also provides avenues for fuel and material testing, and lends itself to studies on how the interaction between people, technology and organisation influences safety operations. The OECD Halden reactor's capacity is small by commercial standards: the energy output of a commercial nuclear power plant ranges from 10 to 80 times the capacity of the Halden reactor.

Concerns over the safe disposal of spent nuclear fuel are real, but technology in this area is fast advancing.

Nuclear power plants use uranium, or a combination of uranium and plutonium, as fuel elements to produce energy for electricity generation. The spent fuel discharged from a nuclear power plant contains fission products as well as minor actinides, both of which are radiotoxic, with half-lives extending to many thousands of years, and obviously a source of public concern.

Nuclear power plants may, however, use a combination of thorium and plutonium as nuclear fuel. These generate lower amounts of the longer-lived minor actinides, and make for better waste management. Efforts are also under way to burn minor actinides using accelerator-driven systems and fast reactors.

The continued, safe operation of the Halden nuclear plant, sited near residential areas and an industrial paper mill, suggests that nuclear reactors can be creatively and safely located in a densely populated country. Hence, we are optimistic that there is scope for Singapore to tap nuclear energy to ensure its long-term energy security and provide a sustainable living environment.

Dr Carlo Vitanza is head of marketing and development, OECD Halden Reactor Project, Norway. Dr Julian Kelly is chief technology officer, THOR Energy, Norway. Professor Seeram Ramakrishna is vice-president (research strategy), National University of Singapore.