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Introduction
The use of nuclear power for generating electricity attracts hot debate today. Different groups of people are striving to balance the benefits that nuclear power brings and drawbacks that it has imposed on society. Proponents are maintaining that nuclear power is a clean form of energy as it is carbon-free. In the process of generating electricity, unlike coal and natural gas, nuclear power does not release carbon dioxide into the atmosphere, which is one of the main components of greenhouse gases. Besides, nuclear power provides a large-scale, continuous and reliable supply that can never be economically replaced by other renewable resources.

Notably, most opponents are concerned about the safety of continuous usage of nuclear power and hazards associated with it. By recalling the latest nuclear accident in Fukushima following a major earthquake and tsunami, it has led to concerns over the safe and efficient operation of nuclear reactors, especially in occurrence of disasters. All three cores melted during the first three days and the units lost the ability to maintain proper reactor cooling and water circulation functions. Due to high radioactive releases, the accident was rated 7 on the INES scale. Other than operational aspects, fear over the locational use of reactors, nuclear wastes disposal and costs for future running have raised increasing attention.

Design Controversy
In the course of operation, nuclear power plants are subject to criticisms mainly concerning their safety during the process of generating electricity. The main reason is the nuclear disasters can be caused by the defective design of the nuclear power plants.

The most recent nuclear disaster was known as the Fukushima Daiichi, dated on 11th March 2011, was caused more or less by the defective design of its nuclear reactors. In fact, the Fukushima Daiichi reactors are GE boiling water reactors (BWR) of an early (1960s) design supplied by GE, Toshiba and Hitachi, with what is known as a Mark I containment. Reactors 1-3 came into commercial operation 1971-75. Reactor power is 460 MWe for unit 1, 784 MWe for units 2-5, and 1100 MWe for unit 6.

The disaster was triggered by magnitude 9 earthquake accompanied with a mega tsunami. As a result, these led to the inability to remove decay heat in the reactor and finally the core meltdown and radioactive release from three units. The plant first experienced a station blackout due to the flooding of backup critical emergency electrical generation. Following failure of backup water injection equipment, delays in initiating injection of seawater into reactors using portable pumping equipment led to fuel overheating. Subsequently the generation of hydrogen through steam oxidation of the fuel cladding led to chemical explosions causing structural damages and radioactive materials leakage. Many people then doubt the safety of the reactor’s design.

Actually, the Mark I design Boiling Water Reactor used in the Fukushima Power Plant lacks of sufficient safety measurement and is regarded as outdated. Nowadays, the Gen III and Gen III+ improved the internal design of the reactors and include the function of passive cooling system in order to ensure maximum safety. The Passive Containment Cooling System (PCCS) can effectively cool the containment following an accident so that the pressure is rapidly reduced, and the design pressure is not exceeded. The steel containment vessel provides the heat transfer surface that removes heat from the containment and rejects it to the atmosphere. Heat is removed from the containment vessel by continuous natural circulation of air. During an accident, the air-cooling is supplemented by evaporation of water, which drains by gravity from a tank on top of the containment shield building. The positioning of this tank and the central chimney give the reactor building of the operator can flood the reactor cavity space immediately, surrounding the reactor vessel with water to submerge the reactor vessel. This cooling is sufficient to prevent melting the steel vessel wall and spilling into the containment.

Because of the technology advancement, many potential defects of reactors have already improved and it can be deemed safe. Apart from the PCCS, many technical improvements, for instance the Passive Core Cooling System and the Strong Containment Wall of EPR can minimize the risk of explosion of the reactors.

Controversy Over Operational Safety
According to the Nuclear Regulatory Commission (NRC), unplanned events resulting from nuclear power generation is divided into ‘incidents’ and ‘accidents’. Incidents referred to unforeseen events and equipment failures that occur during normal plant operation, with no release of radiation or damage to equipments. Accidents refer to offsite releases of radiation or severe damage to plant equipments. Also, the International Nuclear and Radiological Event Scale classifies (INRES) nuclear events through a ranking system of 7 levels from ‘incidents’ to ‘major accident’. Under such classifications, proponents of nuclear energy may contend that the number of nuclear accidents recorded is low. They maintained that even a major accident and meltdown as at Fukushima in 2011 would not endanger its neighbours.

However, if accidents are redefined as incidents that results in loss of human life and property damage, opponents of nuclear energy see that a very different picture emerges. According to a study by Yuka Hayashi and Andrew Morse,  no less than 76 nuclear accidents happened from 1947 to 2008. They occurred under both normal and emergency conditions, involving meltdowns, explosions, fires, and loss of coolant. It has led to costs beyond property damage, such as injury to workers and malfunctioning of reactors.

Indeed, such controversy concerns over operational safety of the nuclear power system, including technological and man-made accidents. One study conducted by the US Atomic Energy Commission described these occupational injuries and deaths were occurred during construction, operations, inspections and government functions.

For example, in August 2003 blackout on the US East Coast, reactors designed to automatically unlink from the grid and remain in standby mode went into full automatic shutdown instead. This was caused by improper maintenance of backup diesel generators, and such example suggested that relying on backup systems to respond to blackouts presents a great likelihood of failure and can create dangerous situations.

The huge technological problem that nuclear scientists face today is that nuclear reactors are very hard to turn off. Even after the nuclear chain reaction has been stopped and the reactor is shut down, the fuel continues to burn and produce heat. In the Fukushima accident, the reactor complex shut down smoothly enough, but the atomic fuel continued to burn and produce heat. Yet, with the reactor shut down, internal systems for cooling the reactor were out of order, causing the meltdown of reactor cores.

Another example that linked closely with man-made operational safety is the incident happened in Trojan Reactor in Oregon in 1999. When operators were beginning to load spent fuel into dry storage at the reactor, they found that the zinc-carbon coating intended to protect against borated water had started producing hydrogen, causing a small explosion. Follow up investigations identified that the likely causes are poor quality assessment, not following procedures and failure to document previous repairs. One laughable mistake occurred at Rancho Seco in California, where an employee accidentally dropped a light bulb into the reactor. This has led to short-circuiting sensor arrays and increase in pressure that almost cracked the reactor vessel.

No matter how well a system is designed, operator error is still a very common causal factor of system accidents. People are fallible, even those working at the nuclear power plant. As the NRC Chair once commented, a surprising lack of professionals is the root of the problem. Also, cultural differences in operations may have grave implications for plant safety and nuclear power regulations. It remains difficult to standardize approaches to management and a more practical way is to train more professionals and introduce them into the nuclear industry.

Geographical Controversy
Choosing a place for installation of nuclear power plant is far difficult compared with the classical one (coal, natural gas etc.) as there are harsher requirements as to ensure safe operation of nuclear power plant.

Internationally, countries would follow the criteria listed by IAEA  (e.g. slope gradient, water supply) and launch detailed investigation before installation of nuclear power plant. However, as there are side-effects of producing electricity through nuclear fusion technology, guarantee of safe operation environment is not enough in choosing site for nuclear plant. Reflected in recent controversy, impacts to environment and health of human are two important areas needed to consider in site selection. In debates over environmental impact and health issue, pollution is usually regarded as the fundamental concern in installation of nuclear power plant as triggering disasters in natural environment and human society. In the following, two types of pollutions: thermal pollution and tap (or ground) water pollution would be discussed with relevant examples in how it alternated site selection of the plant.

Thermal water pollution

Thermal water pollution is a common problem that found among industries and power plants. During the process of production (or energy generation), large amount of water is used for cooling purpose and would discharge back to the source of water in form of warm (or hot) water. As a result of sudden increase in water temperature, the bio-diversity is disturbed since local species (especially marine species like fish and crab) could not adapt to the change of environment. Furthermore, it would affect the food chain and lead to natural disaster like Red tide, which would influence economic activity of human society negatively. Although there are researches suggested that nuclear contributed as little as averaging about 3.7 x 10 super(11) Bq y super(-1) to thermal pollution, it remains one of the important factors in installation of nuclear power plants as numbers of pollution cases are found in the past. For examples, in Vermont of the US, the Entergy Nuclear was complained in 2008 and sent to the court for discharging up to 543 million gallons of hot water into the river, which badly affected the population of shad which already decreased 99% from 1992 to 2007 and hence the local fish industries. Moreover, in case of Lake Anna, the discharge of hot water by Dominion Virginia power had generally divided the natural environment into two parts: cool side and hot side. Apart from affecting natural species and activities of local people, it also damaged the development of tourism over the area as devaluing the environment. Despite improvement of power plant in Waterford  through installation recycle system showed success in managing thermal pollution as amount of cooling water needed greatly reduced and the fish kill rate lowered by 90%, the unsolved thermal pollution problem could not be ignored. As to achieve aim of sustainable development, site selection of nuclear power plant should consider the nearby ecosystem and impact on local economy.

Tap (ground) water pollution

Leakage of radioactive chemical is always the most perplexing issue for installation of nuclear power plant, especially after Fukushima nuclear accident which alarmed the world on potential danger of nuclear power. Hence, location of nuclear power plant became controversy because of fear of citizen towards its operation and storage of radioactive materials. In the following, the case of Exelon  would be used to analysis on that. Exelon which is one of the largest energy producers in the US, was discovered that leaving the problem of radioactive leak unsolved for 9 years in 2006. Due to improper management and damage of pipes, radioactive tritium leaked and contaminated nearby soil and water source, which affected tap water of citizens. Although researches  done afterwards showed that it would not threaten health of people as only increase the annual exposure of human from normal eating and drinking less than 1%, it could not ease worry of people towards nuclear power plant nearby.

From the above case, it is not just shown the limitation of regulation and self-censorship in terms of company responsibility, it also raised the other concerns in site selection of nuclear plant. Apart from investigation of geographical characteristic like slope gradient and existence of fault, underground situation like the existence of artificial facilities and ground water storage should also be consider as part of criteria in selection.

Controversy Over Waste Management
Radioactive wastes containing harmful radioactive material are generated mostly through nuclear power generation. Radioactive waste is dangerous to human and nature, because of the ionizing radiation released during the radioactive decay process. A proper regulation is needed in order to protect human and the environment from the wastes.

Radioactivity decreases over time, so a proper way to reduce radioactive wastes damage is to isolate and store them for a period of time until it is no longer a threat to human and nature. The decisive factor determining the duration of isolating the wastes is the physical half-life time that the various radioactive materials decay, ranging from fractions of seconds to many millions of years. Spent nuclear fuel or by-products of nuclear reprocessing are mostly high-level wastes. They must be stored for a year or more. Deep burial is needed for the high-level wastes.

However, general public still doubt about the safety level of disposal facilities of high level radioactive wastes, and that the general acceptance of them is not high. Though the amount of radiation exposure during people’s daily live may even higher than being exposed to the area near to those facilities. The lack of acceptance of nuclear power plants may actually impacts the acceptance of disposal of nuclear wastes. Indeed there are possibilities of explosion, meltdown for a nuclear power plants, but these won’t happen to the disposal of nuclear waste. People just tend to connect two things together. But to ease public’s concerns, a range of waste disposal options are suggested, though deep burial is still the method chosen by majority.

Borehole disposal is a combination of human and natural effort to achieve safe disposal of radioactive materials. Borehole facilities are usually relatively small in size at the surface, disposing the waste through a narrow diameter. The operational and construction cost of it is also low. Therefore it is a good choice when the volumes of waste are small.

Cost for Running Nuclear Energy
Nuclear power is the use of sustained nuclear fission to generate heat and electricity. Nuclear power plants provided about 5.7% of the world's energy and 13% of the world's electricity, in 2012. There are costs for generating nuclear energy and also running the nuclear plant. The construction cost of building the plant, the cost of waste disposal from running the nuclear energy and the risk for running the nuclear plant.

The construction cost of building the plant

The main cost in producing nuclear power comes from building the power plant in the first place. Building a plant is a multi-billion dollar undertaking.

According to the studies conducted by Emerson, it indicate that the deployment of a "digital power plant of the future" automation concept (Figure 1) can lead to capital, construction, and installation cost savings of $15 million to $20 million. In addition, O&M savings of $2 million to $4 million per year for the typical 600-MW to 800-MW coal-fired unit are possible.

The Cost of Waste Disposal from the Plant

There is the problem of nuclear waste disposal. The nuclear industry also produces a large volume of low-level radioactive waste in the form of contaminated items like clothing, hand tools, water purifier resins, and (upon decommissioning) the materials of which the reactor itself is built.

Both nuclear reactors and uranium enrichment facilities must be decommissioned, returning the facility and its parts to a safe enough level to be entrusted for other uses. After a cooling-off period that may last as long as a century, reactors must be dismantled and cut into small pieces to be packed in containers for final disposal. The process is very expensive, time-consuming, dangerous for workers, hazardous to the natural environment, and presents new opportunities for human error, accidents or sabotage.

The Risk of Running Nuclear Energy

There are other costs, or more exactly risks, such as the dangers of accidents and the danger of dangerous nuclear materials getting into the hands of our enemies. For example, the Japan nuclear crisis, Japan's Nuclear and Industrial Safety Agency said the radiation level at the Fukushima Daiichi nuclear power plant reached 10 millisievert per hour at one point on Wednesday morning 16th March 2011. The radioactive substances had spread in case of radiation leakage from nuclear power plants and cause a pollution which has widely spread all over the world. The significant pollution of sea water along the coast near the nuclear plant might persist, because of the continuing arrival of radioactive material transported towards the sea by surface water running over contaminated soil.

Statistics On Nuclear Power Controversy
People have always worried the leakage of radioactive substances from nuclear power plants or nuclear waste may cause severe impacts on their lives. A survey  involving 18 countries had been conducted in 2005. Less than one-third of interviewees supported the construction of new reactors. This shows that people’s feelings towards nuclear energy are negative. This is possibly a consequence of the past accidents of nuclear reactors. And after the Fukushima accident, it is likely that the result will even be lower. It is not possible to have a method that can ensure 100% safety. Therefore, the safety problems towards the public may have to rely on time to show that the technological improvement has enhanced the safety a lot.

Result of another survey indicated that people are much more supportive on building nuclear power plants if those plants are built in the areas which are far away from where the respondents lived. So it may propose that people see the benefits of using nuclear energy. They support the use of nuclear energy but worried about harming their own health.

Construction cost of nuclear power plant involves billions of dollars and a few years construction time. Because of the high cost and long period of construction, although nuclear power plant can generate electricity with a lower price than fossil fuels, little has been started by private companies as it takes too long time to get benefit. This suggests the use of nuclear energy relies heavily on governments efforts to operate.

It is worth noticed that there are other benefits of using nuclear power apart from the controversy mentioned above. Statistics3 in 2009 show 90% of carbon dioxide pollution is caused by burning fossil fuels. Since nuclear power is a source of carbon-free energy, we do not need to worry about the problem of emitting much carbon dioxide and worsen the problem of global warming.

Moreover, The World Energy Council predicted by the end of 2008, the amount of coal consumption is available for about 128 years more, and that of oil and natural gas are available for about 41 and 54 years more respectively. As a result, in order to maintain the steady electrical power supply in the long run, nuclear power has become an alternative way to generate electricity in many countries as it is the best energy source to replace fossil fuels.

Furthermore, nuclear energy produced different valuable byproducts3. The first example was the waste heat which could be used for desalination. Japan had used the heat to produce 3,000 cubic meters of potable water per day. Another illustration was the radioisotopes which could be used in medical treatments. Some of which could only be produced from nuclear reactors. This shows another positive side of using nuclear power other than generating electricity.

An estimation of 16% of the world’s electricity was generated by nuclear power. It is also projected the world’s electricity generated by nuclear power would reach 30% by 2030 and the energy consumption in the world would be increased by 33% between 2010 and 2030. This suggests that nuclear energy in the future will probably play a major role in power generation and is likely to become more and more significant.

Nuclear Development in Russia and the US
"Nuclear power is one of few means of energy production that can meet the substantially increased global demand for electricity but without the extreme atmospheric emissions, which are characteristic for fossil fuels. " At the same time, the future of nuclear power is still being debated.

There is a bilateral meeting in 2002 between Russia and US, two of the biggest consumption of energy. The motive of the meeting targeted to the future of nuclear power, energy, ecology and safety. It aims at utilizing the atomic energy for the sack of supporting the economic growth, environmental concern, improving the living conditions and preventing nuclear weapons.

A substantial increase for energy consumption is inevitable in the 21st century, especially for those developing countries, like china. It is expected that fossil fuel will continue to be the primary source of energy consumption in the next decade. However, there is an international controversy concerning the ecological consequences of the consumption of fossil fuels. "Electric power and transportation characteristically involve substantial atmospheric emissions which result in local (smog), regional (acid rain) and global (climate change) environmental degradation."

 Suggestions for Improvement of System of Nuclear Energy 

During the meeting, there are four suggestions to improve the circumstance, first increasing the efficiency of electricity production and consumption. Second, using renewable energy sources other than hydroelectric power, third development of nuclear energy and last for the carbon segregation. Beside, there is a responsibility for US and Russia to decrease the storage of the nuclear wasting for the military use.

Apart from it, it is recommended that there is a possible collaboration plan between two countries. First, setting several priority directions, it may be developing of nuclear power to fast reactors or more safety. Conducting research with different assessment methods and develop jointly. Second, may be global organization of the reactor and fuel cycle, leasing the same high-technological installment to the development countries to ensure the safety concern. Last, with regard to the human resources, it should be established some scientific-technical schools to train up some young professions in this aspect. It is foreseeable that there is much of the collaboration plans between two counties and the world, which could enhance the usage of nuclear power in the nearly future.

Conclusion
All in all, the world is in need of cleanly-generated electricity in the coming years, and the use of nuclear power for such generation has become a fundamental part of our life. Despite some dangerous and hazardous nature of nuclear energy, it is impossible to exclude the use of nuclear power for producing electricity on a large scale. So, there is an urgent need to draw preventive measures and improvements to build a safer and more efficient environment for using nuclear energy. Designs, operation and location of nuclear reactors have to be improved to withstand any catastrophic events that may be happening in the future. Also, it is of vital importance to figure out a way to disposal radioactive wastes, which is highly toxic and harmful to public health if it is left within the atmosphere. Further, a better evaluation of the costs for running nuclear energy should also be considered in the near future to maintain a balance between energy efficiency and expenses.

Reference
Paul R. Portney, ‘Nuclear Power’

The Nuclear Debate, Updated April 2012

Acton J.M. & Hibbs M, Why Fukushima was preventable, March 2012 Carnegie Paper

George P. Shultz and Sidney D. Drell, The Nuclear Enterprise - High-Consequence Accidents: How to enhance Safety and Minimize Risks in Nuclear Weapons and Reactors, Hoover Institution Press, 2011

Editor in Chief, Steven B. Krivit, Nuclear Energy Encyclopedia: Science, Technology, and Applications, Wiley Publication, 2010

“Suspected Breach in Nuclear Plant Reactor,” Weekend Today, March 26-27, 2011

Yuka Hayashi and Andrew Morse, “Japan Officials Make Gains as Nuclear Crisis Sparks Rift,” Wall Street Journal, March 16, 2011

Benjamin K Sovacool, Contesting the Future of Nuclear Power, World Scientific Publishing Co. Pte. Ltd 2011

Martin Cohen and Andrew Mckillop, The Doomsday Machine, Palgrace Macmillan 2012

AEA. 26 NUCLEAR POWER PLANT SITE SELECTION, http://www.iaea.org/OurWork/ST/NE/NEFW/documents/RawMaterials/TM%20JOR/26%20NUCLEAR%20POWER%20PLANT%20SITE%20SELECTION%203.pdf

Group fights nuclear plant's water releases, http://search.proquest.com.ezproxy.cityu.edu.hk/docview/342370389/13D780F112F65009559/8?accountid=10134

Judge: Nuclear plant's wastewater discharge was wrong, http://search.proquest.com.ezproxy.cityu.edu.hk/docview/463069187/13D78CB414478322CF6/9?accountid=10134

Foe Of Nuclear Power Station Wants DEP Removed From Pollution Case, http://search.proquest.com.ezproxy.cityu.edu.hk/docview/456712567/13D780F112F65009559/16?accountid=10134)

RADIOACTIVE LEAKS FOUND AT REACTORS, http://search.proquest.com.ezproxy.cityu.edu.hk/docview/222676474/13D79A88B664C2E02FF/20?accountid=10134

Exelon admits its fault in leak: Apologetic officials call risk minimal, http://search.proquest.com.ezproxy.cityu.edu.hk/docview/463037318/13D7CAB3B5376C5ECE8/3?accountid=10134#center

Organisation for Economic Co-operation and Development. (2010). Radioactive waste in perspective OECD Publishing

Streffer, C. (2011). Radioactive waste : Technical and normative aspects of its disposal. Berlin; New York: Springer

Wikipedia.Http://en.wikipedia.org/wiki/Radioactive_waste

Key World Energy Statistics 2012 (PDF). International Energy Agency. 2012. Retrieved 2012-12-17.

Joyce Dasch, Director, Power Marketing, Emerson Process Management

Benjamin K. Sovacool (2011). Contesting the Future of Nuclear Power: A Critical Global Assessment of Atomic Energy, World Scientific

The guardian Japan nuclear crisis, Wednesday 16 March part one

http://en.wikipedia.org/wiki/Nuclear_power#cite_note-1,

Ponomarev-stepnoi V V; Gagarinskii, A Yu; Moniz, E J; Gottemoeller, R; Poneman, D ,(2002) The Future of Nuclear Power: Energy, Ecology, and Safety, Atomic Energy 93. 5 ,

N N; Kuznetsov,(2002), The Future of Nuclear Power: Energy, Ecology, and Safety, Atomic Energy 93. 5,

Feiveson, H. A. (2009). Daedalus. A Skeptic’s View of Nuclear Energy, 138, 60-70,

Greenberg, M. R., West, B. M., Lowrie, K. W., & Mayer, H. J. (2009). The reporter’s handbook on nuclear materials, energy, and waste management. Nashville: Vanderbilt University Press,

Stieglitz, R., & Docksai, R. (2009). The Futurist. Why the World May Turn to Nuclear Power, 43, 16-22,

World Energy Council. (2010). Survey of Energy Resources 2010. Retrieved 2010, from http://www.worldenergy.org/publications/3040.asp