Nuclear power to generate energy: Is it feasible?

Dr Mathu H Liyanage

The feasibility of preventing or at least mitigating global warming by adopting nuclear power has ignited the debate on the use of nuclear energy in the wake of Japan’s spectacular explosion at the Fukushima Daiichi nuclear plant caused by the ferocious earthquakes in recorded history and the three-foot tsunami wave

Global warming is caused by nature itself as well as man-made problems. One natural cause is the release of methane gas, a greenhouse gas, from arctic tundra and wetlands. The other is caused by the earth going through a cycle of climate change which lasts about 40,000 years.

The man-made problems such as pollution caused by burning fossil fuels made of organic matter, coal or oil, generating greenhouse gas CO2 (carbon dioxide), and releasing of methane into the atmosphere by mining coal and oil, do the greatest damage. Population is yet another factor. More people means more food, tilling of more land for food, rearing of animals such as cows, sheep, goats on farmland for manure and dairy products increase methane in the atmosphere considerably. It also involves more methods of transport, motor vehicles and railways.

We breathe out CO2, and trees which convert CO2 to oxygen are felled (deforestation) as more land is prepared for agriculture and for building houses and articles of furniture. These activities build up the methane gas to significant levels. Besides, carbon dioxide and methane are released as a result of decay of food, vegetation and paper dumped in landfills and when sewage wastes break down. Many industrial processes such as cement and liquid natural gas production, and coal mining produce or emit a variety of greenhouse gases. The first five countries ranked as the great polluters by 2007 emissions are: See table 1

The conventional or traditional energy sources consist primarily of coal, natural gas and oil formed from decaying plant and animal material over hundreds of thousands to millions of years.

Most of them are burned to produce energy through power plants and automobiles. In fact, conventional sources of energy made the Industrial Revolution possible, starting with the textile industry in the 18th Century and the modern society.

The most significant characteristic of these energy sources is that they are non-renewable and would be reduced to zero over the years. The renewable energy, on the other hand, is energy that comes from natural resources such as sunlight, wind, rain, tides and geothermal heat which are naturally replenished or renewed.

It is interesting to note that during the five-year period, 2005 to 2009, worldwide renewable energy capacity grew at rates of 10 to 60 percent annually for most technologies. See table 2

It is reported that in 1908, about 19 percent of global final energy consumption came from renewables, 13 percent from biomass (plant material) used for heating, 3.2 percent from hydroelectricity while new renewables like modern biomass, biofuels (bioethanol - an alcohol made by fermenting the sugar components of plants mostly from sugar and starch crops) and biodiesel made from vegetable oils, animal fats or recycled greases, small hydro, wind, solar and geothermal - the energy is obtained by tapping the heat of the earth from the deep earth’s crust in volcanically active locations.

To be continued