Once, the President of the United States of America (1954) proudly declared that his country had found a way to end the global energy scarcity forever. The US nuclear developer Lewis Strauss commenting on the bold declaration made by their President said, as a result of the commercial availability of enormous and infinite energy sources in the decades to come, the market economy may be faced with problems related to energy costing. It manifested the high hopes, both politicians and scientists have had placed on nuclear energy.
As students we have learnt that the physical world consists of matter and energy. The early world recognised heat energy (fire, solar), kinetic energy (moving objects) and potential energy (special positioning of objects) and in the late 19th century scientist ‘Becquerel’ discovered radioactivity. Thereafter, it was proved (by Maxwell) that electro-magnetism could produce radiation and solar energy too has radiation. Rays like x,α,β,ɤ and cosmic waves have also been identified.
It was Albert Einstein who ended the dichotomy between matter and energy proving that matter could be converted to energy and vice versa (1913). Later Italian scientist Enrico Fermi experimentally proved that matter could be destroyed and energy could be produced by way of dividing atomic nuclei- (1931).
According to Einstein’s famous relationship, energy = mass x (speed of light) 2, enormous, theoretically infinite energy could have been produced, converting mass into energy. The first atomic bomb (both Fermi and Einstein were involved with) in 1945 and the first submarine powered by a nuclear reactor (1949), proved the fact that humans could use that enormous energy source.
To us, terms such as radiation and radioactivity very often carry cautionary notes. It is natural as long as we could hear about the horrible calamities of Hiroshima-Nagasaki (1945), nuclear power plant accidents in Three Mile Island - USA (1979), Chernobyl – Ukraine (1986) and Fukushima, Japan (2011). However, radioactivity is everywhere and it is a natural phenomenon from sunlight to X-rays.
Radioactivity is a natural phenomenon which is created by properties of certain unstable atoms that could spontaneously transform into other atoms, while emitting radiation. These unstable radioactive atoms could be found in human bodies, biotic forms including food and in natural environments. (Water, soil and atmosphere).
Radioactivity is being measured using unit Becquerel (Bq) and the unit of measurement of biological effect on humans is called Sievert (Sv).The safety level for humans, against exposure to radioactivity should be less than 1 milli Sv (10-3 Sv). In France this level is 2.4 msv.
After the discovery and identification of radioactivity, there was a human tendency to use it for various purposes such as power generation, chemistry and biology (study of cells etc.), geology and archeology (carbon dating), agriculture and medicine (new varieties, treatments) and in industry (sterilising medical equipment, conserving foods, fractures and leakage detection etc.)
When radioactivity is used, it needs to be handled with utmost care, for it may cause damage to biotic forms. High energy radiation may cause ionization. In solar cells (photovoltaic), it generates electricity, but in human cells, it may destroy or kill them or change its chemicals and hence biological characters (creating cancer cells), or deform them and create malfunctioning the biological process, thereby creating deformation (blindness) for generations to be born. However, all radiation waves do not cause this ionization. Non-ionization waves like our radio waves, normal solar waves, mobile phone waves, power system waves and X-rays may not cause harmful effects to human body.
All use of radioactive materials produce radioactive waste which means substances that cannot be reused or reproduced which require special management.
For example, in France where nuclear power usage is 80 percent, the per capita nuclear waste is 2 kg, whereas industrial waste is 2500 kg, household waste is 365 kg and carbon emission is 11,000 kg. Although the volume is small, its effects are far more dangerous than other waste.
As far as the nuclear club of countries are concerned, (the US, France, the UK, Russia, India, China and Japan etc.), only 4 per cent of nuclear waste is generated from applications on industry and medicine whereas 96 percent waste comes from power generation, defence and research related activities
There is a concept called half life cycle in radioactivity. That means for a certain time period, radioactive materials decay down to half the level of radioactivity, naturally and that process may lead to new substances which are stable and harmless in nature. The time period for this process may differ from a fraction of a second to decades and it may be used properly to make clocks and dating archeological artifacts etc.
So when we dispose radioactive waste, we have to thoroughly consider the amount of high level elements and their life cycle, disposal structure, the packaging of waste and the geology of the site (which acts as natural barriers). In that sense, contaminated milk powder or open dumping of decayed-down radioactive elements in the Maharagama cancer hospital site may give rise to serious health concerns. However, it has to be noted that civil nuclear applications are a comparatively less dangerous activity. Also, in this regard, one may ask about electricity or heat generation, using nuclear power.
Energy is the lifeline of modern society and the most demanding commodity. During the period between 1950 - 2010, the value of petroleum products had been raised at a rate more than that of gold! Fossil fuels (oil, gas, coal and shale) now comprise 82 per cent of global energy consumption (13 Gtoe-2012) and there are two constraints to this consumption trend.
Most of the fossil fuel resources would exhaust by 2050. Burning of fossil fuels increases global warming and it would reach a dangerous level (20 C) by 2035.
The world population reached the 7 billion mark in 2012 (200 years ago it was 1 billion) and it is estimated that it would reach 8.4 billion in 2030 and 9.3 billion in 2050. (Average growth rate per annum is 0.8 %). Human per capita energy consumption rate is faster than that of the population growth. (Modern information age humans consume 130 times more energy than stone age human beings or their basic biological energy needs.) In 2012, global energy consumption is 13 Gtoe and it is predicted to be 17 Gtoe by 2030 and 22 Gtoe by 2050. (Average growth rate is 1.8% per annum.) In case of electricity demand, the maximum demand in 2012 was 13 Tw and it would be raised to 17 Tw in 2030 and 30 Tw in 2050. (Average 2% growth)Supplying energy while preserving the environment could be the greatest challenge human beings are now faced with. Can nuclear energy be a sustainable solution to that uphill challenge?
The nuclear fuel still used is uranium (uranium-235). Commercially available reserves are 5.3 mn tonnes and it is capable of producing energy for another 100 years. One important aspect of nuclear energy is that fuels can be produced enriching existing materials. Now fast reactors are introduced to use isotope U-238, experiments are being done to use thorium which can be enriched to U-233. (Sri Lanka has a huge thorium deposit.) Waste too can be reprocessed to produce fissile materials like plutonium. The new breeder reactor can breed its own fuels! So quantity-wise, nuclear fuels can be produced for another 100-200 years. Now experiments are being carried out to use another way - Nuclear Fusion – by combining the hydrogen isotope and producing energy (like in the Hydrogen bomb).
Although the processing of fuel and building plants produce carbon emission, in the case of nuclear chain reaction which produces heat and electricity, there is no carbon emission and hence no global warming.
New technologies are being developed rapidly like waste reprocessing and - SMARTsmall scale (100 mw) reactors (Korea). However, due to high capital cost, high tech operation, perfect infrastructure facilities, high capable human resources, stringent regulations and international law, accidents-leakages in plants discourage the world to accept nuclear energy as a suitable fuel option. Any country, including Sri Lanka, should carefully measure the benefits and constraints when they enter the nuclear arena. However, knowledge and research on this field must be carried out because one day (if possible) crises on global energy might be solved by this tiny atomic world.