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Text 1. Energy development
Energy development is the effort to provide sufficient primary energy sources and secondary energy forms to fulfill supply, cost, impact on air pollution and water pollution, and whether or not the source is renewable.
Technologically advanced societies have become increasingly dependent on external energy sources for transportation, the production of many manufactured goods, and the delivery of energy services. This energy allows people who can afford the cost to live under otherwise unfavorable climatic conditions through the use of heating, ventilation, and/or air conditioning. Level of use of external energy sources differs across societies, as do the climate, convenience, levels of traffic congestion, pollution and availability of domestic energy sources.
All terrestrial energy sources except nuclear, geothermal and tidal are from current solar insolation or from fossil remains of plant and animal life that relied directly and indirectly upon sunlight, respectively. Ultimately, solar energy itself is the result of the Sun's nuclear fusion. Geothermal power from hot, hardened rock above the magma of the Earth's core is the result of the decay of radioactive materials present beneath the Earth's crust, and nuclear fission relies on man-made fission of heavy radioactive elements in the Earth's crust; in both cases these elements were produced in supernova explosions before the formation of the solar system.
Relative cost of electricity generated by different sources
A. Fossil fuels
Fossil fuels sources burn coal or hydrocarbon fuels, which are the remains of the decomposition of plants and animals. There are three main types of fossil fuels: coal, petroleum, and natural gas. Another fossil fuel, liquefied petroleum gas (LPG), is principally derived from the production of natural gas. Heat from burning fossil fuel is used either directly for space heating and process heating, or converted to mechanical energy for vehicles, industrial processes, or electrical power generation.
Pros
- The technology and infrastructure already exist for the use of fossil fuels.
- Petroleum energy density in terms of volume (cubic space) and mass (weight) is superior to some alternative energy sources (or energy storage devices, like a battery (electricity)).
- Fossil fuels are currently more economical, and more suitable for decentralized energy use
Cons
- Petroleum-powered vehicles are very inefficient. Only about 30% of the energy from the fuel they consume is converted into mechanical energy. The rest of the fuel-source energy is inefficiently expended as waste heat. The heat and gaseous pollution emissions harm our environment.
- The inefficient atmospheric combustion (burning) of fossil fuels in vehicles, buildings, and power plants contributes to urban heat islands.
- The combustion of fossil fuels leads to the release of pollution into the atmosphere. A typical coal plant produces in one year:
ü 3,700,000 tons of carbon dioxide (CO2), could be the primary cause of global warming.
ü 10,000 tons of sulfur dioxide (SO2), the leading cause of acid rain.
ü 500 tons of small airborne particles, which result in chronic bronchitis, aggravated asthma, and premature death, in addition to haze-obstructed visibility.
ü 10,200 tons of nitrogen oxides (NOx), leading to formation of ozone (smog) which inflames the lungs, burning lung tissue making people more susceptible to respiratory illness.
ü 720 tons of carbon monoxide (CO), resulting in headaches and additional stress on people with heart disease.
ü 220 tons of hydrocarbons, toxic volatile organic compounds (VOC), which form ozone.
ü 170 pounds (77 kg) of mercury, where just 1⁄70 of a teaspoon deposited on a 25-acre (100,000 m2) lake can make the fish unsafe to eat.
ü 225 pounds (102 kg) of arsenic, which will cause cancer in one out of 100 people who drink water containing 50 parts per billion.
ü 114 pounds (52 kg) of lead, 4 pounds (1.8 kg) of cadmium, other toxic heavy metals, and trace amounts of uranium.
- Fossil fuels are non-renewable, un-sustainable resources, which will eventually decline in production and become exhausted, with dire consequences to societies that remain highly dependent on them. (Fossil fuels are actually slowly forming continuously, but we are using them up at a rate approximately 100,000 times faster than they are formed.)
- Extracting fossil fuels is becoming more difficult as we consume the most accessible fuel deposits. Extraction of fossil fuels is becoming more expensive and more dangerous as mines get deeper and oil rigs must drill deeper, and go further out to sea.
- Extraction of fossil fuels results in extensive environmental degradation, such as the strip mining and mountaintop removal of coal.
B. Nuclear energy
Nuclear fission
Nuclear power stations use nuclear fission to generate energy by the reaction of uranium-235 inside a nuclear reactor. The reactor uses uranium rods, the atoms of which are split in the process of fission, releasing a large amount of energy. The process continues as a chain reaction with other nuclei. The energy heats water to create steam, which spins a turbine generator, producing electricity.
Depending on the type of fission fuel considered, estimates for existing supply at known usage rates varies from several decades for the currently popular Uranium-235 to thousands of years for uranium-238. At the present rate of use, there are (as of 2007) about 70 years left of known uranium-235 reserves economically recoverable at a uranium price of US$ 130/kg. The nuclear industry argue that the cost of fuel is a minor cost factor for fission power, more expensive, more difficult to extract sources of uranium could be used in the future, such as lower-grade ores, and if prices increased enough, from sources such as granite and seawater. Increasing the price of uranium would have little effect on the overall cost of nuclear power; a doubling in the cost of natural uranium would increase the total cost of nuclear power by 5 percent. On the other hand, if the price of natural gas was doubled, the cost of gas-fired power would increase by about 60 percent.
Opponents on the other hand argue that the correlation between price and production is not linear, but as the ores' concentration becomes smaller, the difficulty (energy and resource consumption are increasing, while the yields are decreasing) of extraction rises very fast, and that the assertion that a higher price will yield more uranium is overly optimistic; for example a rough estimate predicts that the extraction of uranium from granite will consume at least 70 times more energy than what it will produce in a reactor. As many as eleven countries have depleted their uranium resources, and only Canada has mines left which produce better than 1% concentration ore. Seawater seems to be equally dubious as a source. As a consequence an eventual doubling in the price of uranium will give a marginal increase in the volumes that are being produced.
Another alternative would be to use thorium as fission fuel. Thorium is three times more abundant in Earth's crust than uranium, and much more of the thorium can be used.
Current light water reactors burn the nuclear fuel poorly, leading to energy waste. Nuclear reprocessing or burning the fuel better using different reactor designs would reduce the amount of waste material generated and allow better use of the available resources. As opposed to current light water reactors which use uranium-235 (0.7 percent of all natural uranium), breeder reactors convert the more abundant uranium-238 (99.3 percent of all natural uranium) into plutonium for fuel. It has been estimated that there is anywhere from 10,000 to five billion years worth of Uranium-238 for use in these power plants.
Some nuclear engineers think that pebble bed reactors, in which each nuclear fuel pellet is coated with a ceramic coating, are inherently safe and are the best solution for nuclear power. They can also be configured to produce hydrogen for hydrogen vehicles.
The possibility of nuclear meltdowns and other reactor accidents, such as the Chernobyl disaster, have caused much public fear. Research is being done to lessen the known problems of current reactor technology by developing automated and passively safe reactors. Historically, however, coal and hydropower power generation have both been the cause of more deaths per energy unit produced than nuclear power generation. Various kinds of energy infrastructure might be attacked by terrorists, including nuclear power plants, hydropower plants, and liquified natural gas tankers. Nuclear proliferation is the spread from nation to nation of nuclear technology, including nuclear power plants but especially nuclear weapons. New technology like SSTAR ("small, sealed, transportable, autonomous reactor") may lessen this risk.
The long-term radioactive waste storage problems of nuclear power have not been fully solved. Several countries have considered using underground repositories. Nuclear waste takes up little space compared to wastes from the chemical industry which remain toxic indefinitely. Spent fuel rods are now stored in concrete casks close to the nuclear reactors. The amounts of waste could be reduced in several ways. Both nuclear reprocessing and breeder reactors could reduce the amounts of waste. Subcritical reactors or fusion reactors could greatly reduce the time the waste has to be stored. Subcritical reactors may also be able to do the same to already existing waste. The only long-term way of dealing with waste today is by geological storage.
Pros
- The energy content of a kilogram of uranium or thorium, if spent nuclear fuel is reprocessed and fully utilized, is equivalent to about 3.5 million kilograms of coal.
- The cost of making nuclear power, with current legislation, is about the same as making coal power, which is considered very inexpensive. If a carbon tax is applied, nuclear does not have to pay anything because nuclear does not emit greenhouse gasses such as CO2 nor toxic gases NO, CO, SO2, arsenic, etc. that are emitted by coal power plants.
- Nuclear power does not produce any primary air pollution or release carbon dioxide and sulfur dioxide into the atmosphere. Therefore, it contributes only a small amount to global warming or acid rain.
- Raw material extraction is much safer for nuclear power compared to coal. Coal mining is the second most dangerous occupation in the United States. Nuclear energy is much safer per capita than coal derived energy.
Cons
- The improper operation of a nuclear reactor with no containment vessel can be catastrophic in the event of an uncontrolled power increase in the reactor. For example, the Chernobyl disaster in the Ukraine (former USSR) affected large areas of Europe by moderate radioactive contamination; parts of the Ukraine and Belarus continue to be affected by radioactive fallout.
- Transuranic waste produced from nuclear fission of uranium is poisonous and highly radioactive. Breeder reactors could burn this waste as fuel, fissioning transuranics into much faster-decaying fission products which stabilize at a relatively low level of radioactivity in 100–500 years, but recycling plutonium as MOX fuel in current light water reactors merely transmutes between isotopes of plutonium and offers little reduction in radioactivity.
- Without nuclear reprocessing, whole spent fuel bundles containing transuranic waste must be stored in spent fuel pools, dry cask storage, or a geological repository.
- There can be connections between nuclear power and nuclear weapon proliferation, since many reactor designs require large-scale uranium enrichment facilities.
- Some claim that uranium ore is a limited resource and estimate that current supplies will fail to meet demand in 2026, provided no other deposits are discovered. This claim is strongly disputed; also, breeder reactors would extract about 100 times as much energy from the same amount of uranium.
- Since nuclear power plants are typically quite large power plants, and are, fundamentally, thermal engines, waste heat disposal becomes more difficult at higher ambient temperature. Thus, at a time of peak demand for power for air-conditioning, a power reactor may need to be shut down or operate at a reduced power level, as do large coal-fired plants, for the same reasons.
Words to know:
1. sufficient
2. renewable
3. traffic congestion
4. terrestrial
5. insolation
6. nuclear fusion
7. the Earth's core
8. supernova explosions
9. emissions
10. carbon dioxide
11. sulfur dioxide
12. airborne particles
13. nitrogen oxides
14. dire consequences
15. light water reactor
16. breeder reactor
17. pebble bed reactor
18. nuclear fuel pellet
19. nuclear proliferation
20. underground repositories
21. concrete casks
22. nuclear reprocessing reactor
23. subcritical reactor
24. to apply tax
25. containment vessel
26. contamination
27. ambient temperature
Exercise 1. Explain the meaning of the following words and word combinations:
technologically advanced societies, unfavorable climatic conditions, fossil remains of plant and animal life, decomposition, infrastructure, waste heat, global warming, acid rain, be susceptible to smth., a rough estimate, dubious, nuclear meltdown, carbon tax, greenhouse gasses, radioactive fallout, repository
Exercise 2. Make a written translation of ‘Energy development’ part