Executive Summary
The report focuses on nuclear accidents, their causes, and consequences with significant attention to Three Miles Island, Chernobyl, and Fukushima disaster. The stress is made on the role of engineers in the accidents and the application of engineering ethics. The major finding of the report is that it was negligence in following the safety rules and procedures that led to the accidents. The primary recommendation of the report is that embracing ethical behavior might help prevent similar disasters and minimize their consequences. Challenges faced in providing the required information were mostly presenting it in a compact form without missing any details. It was overcome by producing only the key facts about the catastrophes.
Introduction
Purpose of the Report
This report on nuclear meltdowns analyzes three differing industrial accidents from various countries to ascertain if the appropriate appliance of engineering procedures would have impacted these accidents differently. Through the examination of these disasters, this report aims to provide preventative recommendations through varying engineering practices that aim to alleviate the effect such disasters may cause.
Background of the Report
In recent times, the industrial revolution has seen a shift in paradigms, as many within the industry are opting for large-scale machinery and chemical production over the conventional hand production method (Landes, 1969). This poignant transition has contributed to remarkable increases in the rate of production and consistent growth in the economy; however, it has also increased the rate of industrial based accidents and the severity of such incidents (Lindert & Williamson, 1983).
One of the accidents that have originated from this significant shift would be nuclear disasters. Nuclear accidents are considered one of the most severe industrial related accidents to have occurred as its effects surpass mere direct casualties to inducing more long term detriments to anyone within a large radius. Additionally, it also damages the environment and other life forms. A case study of previous nuclear accidents allows a richer understanding of the causality of such incidents and relatively aids in developing systematic procedures in preventing and mitigating the effects of such calamities.
There are three nuclear accidents studied in this report, which, in chronological order, are:
- Three Mile Island accident in Pennsylvania, United States of America.
- Chernobyl disaster in Ukraine (then Ukrainian SSR).
- Fukushima Daiichi nuclear disaster in Fukushima, Japan.
Scope of the Report
The report aims at providing an in-depth understanding of nuclear power plants, the factors of causation and the effects stemming from the aforementioned nuclear accidents, the role engineers play in such accidents, effective preventative measures that may be implemented in current power plants and operational procedures that may be employed to diminish the effects of such accidents. This report will emphasize the technical details in relation to the accidents which shall not affect the opinion pertaining to the power plant, the controversy surrounding nuclear power, legislative procedures, the operational impacts and the technical details on the chemical process of nuclear fission which is unrelated to the previously named accidents.
Technical Details on Nuclear Power Plants
Nuclear power plants became popular because of the transition towards the extensive use of alternative sources of energy. They use energy from atom-splitting to produce heat. The major element of any nuclear power plant is the nuclear reactor that has a core located in the center composed of nuclear fuel. Uranium and plutonium are the most suitable materials to be used as nuclear fuels. The process of atom-splitting is complicated because sometimes, it is impossible to predict the reaction.
The primary danger of the process is the control of the chain reaction. There are several systems of control including control rods (neutron-absorbing materials at put in or withdrawn from the core during the reaction), coolers (water, graphite or heavy water), and containment designed to protect both the reactor from external intrusion and the outside world from possible internal malfunctions. There are some primary types of reactors exploited, such as light and heavy water reactors, gas-cooled reactors, fast neutron reactors, and light water graphite reactors.
The major reason for most neutral accidents is the melt of core resulting from the inability of coolers to deal with the heat produced inside the reactor’s core once the reaction was stopped by control rods. In this case, fuel rods begin to melt through the containment and reveal radioactivity to the outside worlds (Matson, 2011). It is what caused all three disasters – Three Mile Island, Chernobyl, and Fukushima Daiichi nuclear power accidents.
Because of the technical complexity and potential horrifying consequences of similar accidents, it is vital to involve high-skilled engineers in the process of construction and operation of the nuclear plants and prevention of accidental nuclear occurrences. The primary role of engineers is to make sure that all safety rules and regulations are followed and making check-ups with the aim of assuring the safety. It should be stressed that because the types of the reactors and the coolers are different, engineers have a moral responsibility to know well how to operate them and continuously improve their knowledge and skills.
Three Mile Island Nuclear Generating Station
Nuclear station consists of two units, one operational and one decommissioned after the disaster. The both exploit a pressurized water reactor capable of generating 852 megawatts of electrical energy.
Chernobyl Nuclear Power Plant
Power station operated four graphite-moderated reactors with a capacity of 1,000 megawatts of electrical power each. Todays, they are all inactive.
Fukushima Daiichi Nuclear Power Plant
It is a nuclear power station consisting of six units using boiling water reactors of differing electrical power generating capacities from 460 megawatts to 1,100. All six units were partially of totally damaged.
Nuclear Disasters – The Timeline & Causation
Three Miles Island Accident (Level 5)
It occurred on March 28, 1979, in the second unit. At the time of the accident, the reactor was operating at 97% capacity. There was a malfunction in the second cooling circuit that made the temperature of the primary cooler rise. To deal with the challenge, the pilot-operated relief valve (PORV) opened automatically to cool down the temperature by adding cold water but it did not close automatically as it was supposed to, so the cooling water drained to pressurizer making the control of pressure in the core impossible. With the lack of cooling water, the reactor core was not covered with the cooler that resulted in partial meltdown.
The primary concern is that the operators did not know that the PORV has not closed automatically because their indication panel did not show any problems in the system except for the high pressure in the pressurizer, and they did not have an instrument to check whether the PORV is closed. The operators managed to take control over situation once they analyzed the data and found out that PORV was open (it took them more than 2 hours from 4 am to 6:18).
Closing the valve, they ended immediate emergency, and by late afternoon they restored pressure. However, the problem was in the hydrogen bubble that formed while the reactor core was uncovered. It took operators two days to remove it by opening and closing the valve in the pressurizer and four days in general (from March 28 to April 1) to deal with the accident (Walker, 2005).
It should be noted that the primary causes of the accident were the malfunction of the pump that was supposed to keep the water flowing and the lack of instruments and knowledge of the operators to find out whether the valve was closed. Routine inspection showed that every part of the reactor was functional, but to carry out another one during the accident itself the operators had to open and close the valve, and they did not do it, so it took more time to take control over the situation.
Chernobyl Disaster (Level 7)
The accident took place on April 26, 1986. It was considered to be the worst nuclear plant disaster in history with the heaviest economic, environmental, and health consequences up to 2011 Fukushima Daiichi nuclear plant accident. The disaster began at the unit 4 reactor. It was as well a nuclear meltdown resulting from steam explosion and fire in the reactor building. The most aggravating part of the accident is that the explosion blew the reactor roof open and released vast amounts of radioactivity into the outside environment (Saygin, 2011).
The nuclear reactor at Unit 4 was meant to be closed on April 25 for carrying out the experiment, and the accident resulted from these experiments that were planned prior to the maintenance shutdown of the reactor. There was a plan of gradual decreasing the power of the unit and stabilizing its power. The primary condition of the experiment was that the required level of energy was reached before the beginning of the test.
Because energy decrease turned out to be steeper than planned, the operators were ordered to withdraw the absorbing rods to the nuclear reactor core with the aim of keeping to the initial plan of the experiment. As they withdrew the control rods, it led to the quick increase of the reactor power. It led to higher temperature of the cooler in the lowest sections of the core. It was a dangerous state of the nuclear reactor, and the experiment was to be stopped, but the operators did not realize that the situation was hazardous, do they continued the test.
Understanding that the reactor power increased, the operator decided to insert the absorber rods back, but because of technical malfunction the rods were not inserted. Even as the operator cut them off, it turned out to be late, so the experiment resulted in the drastically high reactor power that led to two massive explosions blowing off the roof and destroying the wall of the reactor building (Malko, n.d.).
Fukushima Daiichi Nuclear Disaster (Level 7)
The accident was primarily caused by the earthquakes and tsunami on March 11, 2011. They led to the equipment malfunction and the disaster itself. The primary concern was the water coolers that ceased operating as the result of earthquake and inability to fix them because of flooding in one of the nuclear plants buildings. It was solved by constant supply of water as a cooler and building confinements to minimize the release of radioactive particles into the atmosphere.
Routine Inspections
These three accidents were the most disastrous in the history of the nuclear industry. Nevertheless, they proved that nuclear power is one of the safest alternative resources of energy because except for Chernobyl there were no human victims dying from direct exposure to radiation in the territory of the power plant. Moreover, they highlighted the significance of the routine inspections. The particular scenario for all three accidents was failing to follow the safety rules.
So, they stressed on the operator’s responsibility for the safety of the society. What changed since the first two accidents is the harmonization of the International standards on nuclear power station construction and operation. Making them higher helps lift the overall level of safety because they imply the use of the newest technologies and equipment and diverse control systems to maintain the safety and prevent the release of radioactive particles into the atmosphere.
Nuclear Disasters – The Impact & Consequences
Direct Casualty & Injury
Three Miles Island Accident
There were no instances of direct casualty and injury because the core meltdown was insignificant and the radioactive particles were not released into the atmosphere.
Chernobyl Disaster
There were 30 immediate deaths that raised to 56 within the next few weeks resulting from injuries during the explosion and exposure to excess amounts of radiation and gases in the building of the nuclear reactor. Most of the victims were nuclear station employees and firemen. They suffered from the acute radiation syndrome. There were also 600 hundred employees and emergency workers affected, 134 of them with acute radiation sickness.
Fukushima Daiichi Nuclear Disaster
There were no deaths related directly to radiation exposure because most of deaths are because of the earthquake and tsunami.
Indirect Casualty & Long Term Health Effect
Three Miles Island Accident
There were no significant health effects of the accident. There were many studies aimed at determining the connection between the accident and the level of cancer mortality but all of them prove that it is either extremely weak, or there is no link at all (Walker, 2005). Nevertheless, the decision to conduct voluntary evacuation of the local people was made with the special stress on moving pregnant women and children within the 20-mile radius.
Chernobyl Disaster
The consequences of the accident were intimidating. First, it led to evacuation, so, more than 336,000 people from Ukraine, Russia, and Belarus left their homes and were forced to look for a new permanent place of residence. The primary impact on health is increasing the risk of cancer and the level of cancer mortality, especially thyroid cancer.
Fukushima Daiichi Nuclear Disaster
It led to the increase in risk for cancer and higher level of cancer such as leukemia, thyroid and breast cancers, etc. There were no other effects because of the immediate evacuation. As for now, more than 1,500 people died from radiation-related cancer.
Environmental Effect
Three Miles Island Accident
This accident did not have significant impact on the environment, because not too much iodine was released into the atmosphere and almost all radioactive particles remained inside the reactor.
Chernobyl Disaster
The impact of the accident is mainly seen through the mutations in plants and animals not to mention the fact that the soils in the territory are not suitable for agriculture because the food grown on them is dangerous.
Fukushima Daiichi Nuclear Disaster
Environmental effects are similar to those of Chernobyl leading to mutations in plants, animal, and fish.
Economical Effect
Three Miles Island Accident
Primary economic impact derived from the need to conduct investigation and clean up the local territory. As the result, this accident cost amounted to $1 billion for cleanup more than and $2,4 of property damages.
Chernobyl Disaster
The economic effect of the Chernobyl disaster goes down to the increase in governmental spendings on dealing with the consequences of he accident. It should be stressed that up to 5 percent of the state budget is devoted to Chernobyl-related programmes such as helping the liquidators and those affected by the disaster and maintaining the safety of the plant by building up the confinement around the Fourth reactor.
Fukushima Daiichi Nuclear Disaster
More than $100 billion of compensation to those affected by the disaster and losing more than 30% of country’s energy potential are the primary economical effects of the accident.
Nuclear Disasters – The Engineers’ Role
Three Miles Island Accident
The engineers’ role was to conduct routine inspection and make sure that all parts are functional. The operators conducted all necessary inspection prior to the accident, however, they demonstrated the lack of knowledge and qualification during the accident itself. Failing to analyze the data to detect whether the PORV was open might be attached to the account of emergency and the fact that the instruments in the control room showed that it was close. Even though the operators did not have necessary instruments, they should have demonstrated more problem-solving skills and orientation as the occasion required and analyzed the data earlier. However, as the whole they managed to take control over situation fast enough, so the consequences of the accident were not that aggravating.
Chernobyl Disaster
The role of the engineers was crucial in this accident. In fact, their actions were what led to the explosion in the reactor and the blowing off the reactor building roof because they neglected the safety rules and regulations. Being aware that the initial condition of the experiment, i.e. the necessary level of the reactor power, was not reached, they decided to carry out the experiment at any cost that turned out to be to high. It should be said that it was not the first experiment of this type, and all previous were failed. So, it would have been better to give up the idea of carrying it out or, at least, control the process and stop it at the initial stage.
Fukushima Daiichi Nuclear Disaster
Initially, the role of engineers is in building the plant. Because Japan is located in the seismic zone, it was not recommended to develop its nuclear industry. Nevertheless, this recommendation was ignored. The building was constructed as seismic stable, but in 2011, earthquake turned out to be too strong. Moreover, road quality is poor, that is why it was difficult for the rescuers to get to the place of emergency.
Preventative Measure & Reduction of Impact
Preventative Measure
The primary way to prevent the accident is through embracing engineering ethics and behaving ethically. First and foremost, specific attention should be paid to safety. It would be ethical of engineers to check their workplaces, equipment, and projects for safety and work only with and on such that comply with all the safety rules and regulations and function perfectly, making sure that materials are of best quality and safe (Sivarethinamohan, 2010).
Second, ethical behavior of engineers can help in preventing accidents through carrying the duties thoroughly, being accurate, and working only in the excellent condition of mind and body. This condition sounds unreal, but the professional engineers should do their best to put it to practice. Next step is assuming broad responsibility (Johnson, 2015). It is the responsibility not only for the lives of engineers themselves but also realizing that every their action could have a direct or indirect effect on the members of their society and their safety.
It implies taking responsibility for every little step in the working place and informing people and the respective organizations of any serious problems or accidents while conducting the project. Finally, ethical behavior can be useful in preventing accidents if the construction firms do not strive for cutting operations cost by ignoring the quality and safety standards, but, instead, realize that doing their job qualitatively will benefit them more than the money they managed to save.
Reduction of Impact
There are to ways for reducing the impact of the nuclear power plants accidents – ethical and constructional. Ethical behavior implies sharing the information about the accident with the audience and relevant organization so that they know that they are in danger and are ready for the consequences. Next, it means not precluding the investigation process and being responsible for the mistakes.
As of the constructional approach, it implies surrounding the reactor with the shelter to reduce the release of the radioactive particles into the atmosphere. Moreover, it includes steps taken during the process of construction such as making confinements more reliable, providing effective escape routes and additional support structures to walls as well as insulate the building.
References
Johnson, C. E. (2015). Meeting the ethical challenges of leadership: Casting light or shadow. (5th ed.). Thousand Oaks, CA: SAGE Publications.
Landes, D. S. (1969). The unbound Prometheus: Technological change and industrial development in Western Europe from 1750 to the present. Cambridge, New York: Press Syndicate of the University of Cambridge.
Lindert, P. H., & Williamson, J. G. (1983). English workers’ living standards during the Industrial Revolution: A new look. The Economic History Review, 36(1), 1-25.
Malko, M.V. (2002). The Chernobyl reactor: Design features and reasons for accident. In T. Imanaka (Ed.). Recent research activities about the Chernobyl NPP Accident in Belarus, Ukraine and Russia (pp. 11-27). Kyoto, Japan: Kyoto University Research Reactor Institute.
Matson, J. (2011). What happens during a nuclear meltdown?Scientific American. Web.
Saygin, H. (2011). Major nuclear accidents and their implications for the evolution of nuclear power. In S. Ülgen (Ed.). The Turkish model for transition to nuclear power (pp. 53-85). Istanbul, Turkey: EDAM.
Sivarethinamohan, R. (2010). Industrial relations and labor welfare: Texts and cases. New Delhi, India: PHI Learning Private Limited.
Walker, J. S. (2005). Three Miles Island: a nuclear crisis in historical perspective. London, England: The University of California Press.