Alternative energy options:

The many benefits of nuclear power

by Dhaneshi YATAWARA

The World Science Day is celebrated every year on November 10. Around the world, this is the favourite day of scientists and enthusiasts. This year, it will be a day for peace and development, giving us a hint of a fresh view.

A nuclear plant

Developing the fields of science and technology is an investment for any country, particularly benefiting the future generations. Though development and peace should walk hand in hand in the growing up process of a nation, many a times these concepts have clashed, as evident in world history. One of the most severe problems would arise in the field of power and energy. We are fast burning up our fossil fuel resources while the generation of power with sun rays and wind is still in the primitive stages. Around the world the demand for power and energy is sky-rocketing. How do we meet this demand? Of course, the solution is in the hands of no one else but scientists.

A perfect solution

The world needs a perfect solution to the increasing demand for power. The survival of mankind and its civilisation depends on the continued power or energy supply. Power and energy are the basics for the development and growth of the human civilisation. According to web-based reports, 14 per cent of the world energy needs was provided by nuclear power two years ago. Though power generation using nuclear power has shown no significant increase over the past two years, the tendency of many industrial countries to divert themselves towards nuclear power as an energy source has grown in leaps and bounds. As local and international experts believe, the current state-of-the-art technology would not leave room for another Three Mile Island or Chernobyl incident.

The world is now more aware and cautious of the negative effects of nuclear power.

Today, among the 30 countries that have nuclear power generation capacity, the percentage of electricity coming from nuclear reactors ranges from 78 per cent in France to two per cent in China. As of March 2008, there were 439 nuclear power plants around the world, while 35 more are under construction, latest statistics reveal. The USA has the most with 104, France is next with 59, then Japan with 55 while Russia has 31 and seven more under construction. The expansion in nuclear power generation is centred in Asia. A total of 20 of the 35 plants under construction are in Asia, while 28 of the last 39 plants connected to the grid are also in Asia.

While technology is concerned, power plants that depend on atomic energy do not operate that differently from a traditional coal-burning power plant.

Both heat and convert water in to pressurised steam which drives a turbine generator.

The key difference is the method of heating. Coal power plants generate power to heat water by burning fossil fuels, whereas nuclear power plants depend on the heat that occur during nuclear fission that emits when one atom splits in to two. Thus the reaction results in a different compound.

Uranium - 238 is the currently used raw material for nuclear power generation.

Uranium 238, better known as U-238, is commonly found across the globe. U-238 makes up 99 per cent of the uranium on Earth, while Uranium-235 (U-235) makes up about 0.7 per cent of the remaining uranium found naturally. Uranium-234 is even rarer, formed by the decay of U-238. U-238 goes through many stages of decay in its lifespan, eventually forming a stable isotope of lead; U-234 is just one link in that chain.

Uranium constantly undergoes very slow spontaneous fission. This is why the element emits radiation, and why it’s a natural choice for the induced fission that nuclear power plants require.

The decay of a single U-235 atom releases 200 MeV (million electron volts). That may not seem like much, but there are a lot of uranium atoms in a pound (0.45 kg) of uranium. So many, in fact, that a pound of highly enriched uranium, used to power a nuclear submarine, is equal to about a million gallons of gasoline.

The radioactive waste - the exhausted raw material used to generate power - has become a major problem for those countries who are converting to nuclear power as a main source of energy. The world has found a solution yet it has not shown much success, being unable to impress the concerned parties who urge a total solution. Theoretically, the atomic reaction is reversible. Thus waste can be converted to its original compound, experts say referring to the theories. How cost effective and reliable the process could be is still doubtful.

But, undoubtedly, the cost would be unbearable for developing countries like Sri Lanka. Still, do we need to dump the atomic power concept solely due to its waste material disposal problem? No need for that. As mentioned above, our scientists have proven that we can use the technology within our limits, thus developing the economy. It only needs a fresh view, standing out of the frame.

Peaceful uses

Nuclear energy for peaceful use is the novel concept the Sri Lankan Atomic Energy Authority is presently concentrating on. Sri Lanka’s Atomic Energy Authority (AEA) is in the process of exploring the possibility of using nuclear energy for future power generation, said Science and Technology Minister Professor Tissa Vitarana, addressing a recent media briefing, held to announce the start of these feasibility studies.

It was revealed at the media conference that the Ministry of Science and Technology has advised the AEA to set up a National Committee on Nuclear Power to study nuclear power as an alternative energy option. This committee which will include academics from the Moratuwa University, officials of the Ceylon Electricity Board and AEA and other experts will be formed soon. According to Ministry sources, the concept depends on the country’s thorium resource. Nearly 30 per cent of the world’s thorium resources are reported to be in the South Asian region - i.e. Sri Lanka and India. So far, thorium resources have not been tapped for power generation. According to reports India is planning to use its thorium resources for the country’s second generation of nuclear power plants. Sri Lanka’s thorium resources are found to be based along the coastal line from Kalutara to Beruwala and in the Eastern Province.

Though power generation by splitting atoms seems to be a distant dream, we have used radioisotopes, an initial stage concept in atomic power, in several instances. There are many success stories of the technology being applied in the local context during the past few years.

Tissue preservation

The Human Tissue Bank is the Model Project of the International Atomic Energy Agency (IAEA), implemented in Sri Lanka as a joint effort of the Eye Donation Society, AEA and the Ministry of Healthcare and Nutrition. In this facility all tissues are sterilised by gamma radiation at a dose of 25 kGy (Kilo Geiger). The Human Tissue Transplantation Act No 48 was passed in 1987, legalising tissue procurement and transplantation in Sri Lanka. This act has stipulated the terms and conditions under which the extraction, processing, storage, retrieval and utilisation of human tissues should be performed in Sri Lanka. It has covered all the legal requirements protecting donors, doctors and recipients.

The Human Tissue Bank is one of the successful projects of radiation technology in Sri Lanka which was supported and coordinated by the AEA. The Model Project SRL/7/003 approved by the IAEA envisages a multi-tissue bank dealing with all donor tissues including amnion, skin, bones, soft tissues (including tendons, ligaments, pericardium, fascia lata and eye sclera).

Food testing

In 2001, a food quality laboratory was set up in Sri Lanka as a project implemented by the AEA under a technical cooperation program of the IAEA.

The need for food testing came to light with the increased demand which developed during the rapid growth phase of the poultry and aquaculture sectors in Sri Lanka. With the present laboratory set-up, services are provided to broiler processors, shrimp exporters and milk producing companies in Sri Lanka. The service is also obtained by regulatory authorities including the Ministry of Fisheries and Aquatic Resources and the Quarantine Division of the Department of Animal Production and Health. Clearance for shrimp exports is provided by the Ministry of Fisheries based on the test results of the laboratory.

The Technical Cooperation Programme of the IAEA facilitate the development of laboratory infrastructure through provision of essential equipment, training for human resources development, expert missions and scientific visits. These inputs helped immensely in capacity building of the staff, and introducing modern technology for food quality assurance. The counterpart funding for implementing the program was obtained through research grants of the University of Peradeniya, National Science Foundation and Council for Agricultural Research Policy.

Since Sri Lanka’s export market depends mostly on spices, fruits and vegetables and several other food items, sterilisation by irradiating the food products adds greater value to the product, making it possible to demand a higher price. The irradiation methods do not have harmful effects on the food items, thus making them safe and effective methods to sterilise these export goods.

Livestock development

Though radioisotopes are commonly used in researches around the world, Sri Lanka has used them as a tool only in a few instances. They made a major contribution to a research done as a joint operation of the Food and Agriculture Organization and the IAEA, following the 1996 World Food Summit held in Rome.

The research done by Professor Oswin Perera and Dr. M.C.N. Jayasuriya, who were then attached to the University of Peradeniya, brought results that were extremely helpful to upgrade the livestock industry, not just in Sri Lanka, but for many developing nations.

Many of the advances which have been made in improving feeding, fertility and health of livestock in these countries would not have been possible without nuclear technologies. By using both stable and radio-isotopes, scientists have come to understand and then to manipulate for greater productivity, the biological processes responsible for growth, production, re-production and disease resistance in different types of farm animals.

“On average, livestock accounts for half of agricultural output when both their direct and indirect contributions are considered,” says Dr. M.C.N. Jayasuriya in his article `Use of Nuclear Techniques in Livestock Productivity’ published following the research.

“Secondly, they are an important component of traditional agriculture, complementing arable cropping. Their contribution to the economic welfare of the people extend beyond the traditional uses of supplying meat and milk.”

Nuclear technology is used in agriculture too

The researchers state that although nearly 80 per cent of the human population and 70 per cent of the cattle, 60 per cent of sheep and 93 per cent of goat population live in developing countries, only 34 per cent of the world production of fresh milk equivalent and 48 per cent of the production of meat are from these countries. And the role of livestock in the human food chain in developing countries is complex and significantly different from the situation in industrialised countries. First and foremost, by providing meat, milk and eggs, livestock provide a crucial source of high quality protein, minerals and vitamins, especially for children and pregnant and nursing women.

According to the researchers, the inability to feed animals adequately throughout the year is a major constraint to improving the livestock industries in developing countries though the breeds and types of livestock in developing countries are well known for their greater tolerance to environmental stresses, fluctuating levels of nutrients and resistance to diseases.

As Dr. Jayasuriya explains in his article, the impact of using isotopic techniques has been most visible in the area of developing feeding strategies for farm animals. For example, isotopic markers have been used in the development of feeding strategies for ruminant livestock such as cattle, buffaloes, sheep and goats. Both radio active (14C, 125I, 51Cr) and stable (15N) isotopes have been used as `markers’ to understand how micro-organisms in the rumen or the fore-stomach of cattle, buffaloes, sheep and goats digest grass and other forages and how the energy, protein, minerals and vitamins produced from these feeds are used in building body tissues or producing milk.

“With the development of highly sensitive immunoassay methods, in particular radioimmunoassay (RIA) using 125I or 3H, it is now possible to measure these hormones which circulate in blood and other tissues such as milk. The measurement of the reproductive hormone progesterone in blood or milk in particular has been valuable for monitoring the reproductive function of the females of most domestic animals. Progesterone produced in the ovary reflects the sexual activity of the animal.

By measuring the level of progesterone using RIA, it is possible to determine when animals are ready for breeding, diagnose pregnancy at the early stages or diagnose non-pregnancy so that animals can be bred again without losing productive lifetime, check whether animals have been correctly inseminated, detect reproductive disorders and devise corrective measures to overcome them. RIA has been highly effective in the more advanced embryo transfer programs.

“Immunoassay methods can also monitor meat and other food products for potentially harmful substances and therefore safeguard their quality,” the researchers state.