The Engineering Challenges of the 21st Century
As the world moves towards prosperity through advancement in science and technology, a reliable and cheap source of energy remains a concern to most governments. This is because energy forms an integral part of the production process that leads to economic, social and political prosperity of a nation.
With increasing competition for the scare energy resources around the world, most governments are threatened by a situation of low productivity. It is evident that the fossil fuel reserves are almost being depleted due to their non renewable nature. This has led to shortages and consequently high prices of energy products such as petroleum.
In response to this situation, most developed countries such as Japan have tuned to the use of alternative technologies to generate power for their production. Nuclear power generation has particularly been used by most developing countries to supplement their energy sources. The choice of this technology is attributed to its great potential in producing large amount of energy.
Besides, the long run costs associated with it are relatively low. However, nuclear power generation has been found to be a very dangerous process if not well implemented. Equipment failures in nuclear power plants have in the past resulted into accidents with serious repercussions on human beings and the environment. In March 2011, an accident occurred in Japan’s Fukushima Duiichi nuclear power generation plant.
The accident occurred after an earthquake and tsunami caused a series of equipment failures in the nuclear power plant. The accident led to lose of lives, contamination of the environment with radioactive materials and evacuation of thousands of Japanese from their homes. Currently, the government of Japan is still grappling with the effects of the accident.
Drawing from the experiences associated with the Chernobyl nuclear power plant accident in Europe, this paper highlights the lessons that the Japanese government can learn in regard to its nuclear disaster. The experiences in terms of the effects and the response measures used in the Chernobyl nuclear power plant accident can be considered by Japan to help it address the consequences of the Fukushima nuclear disaster.
The Benefits of Nuclear Power Plants
A nuclear power plant is made of many materials which are typically radioactive. These materials facilitate the production of energy for human life. Constructing a nuclear power plant involves technological building and Civil Engineering. A nuclear power plant is very useful, but it is also very dangerous when it explodes.
The Terrible Accidents from Nuclear Power Plants
When a nuclear power plant accident involves the breakdown or melting of the viselike portion of the fuel rods in the core of a nuclear reactor, a large amount of radioactive materials get leaked into the natural world (Sevon, T. 2005). Such accidents are complicated and have multiple causes (Clery, D.2011). In order to reduce the damages associated with them, it is important to have a plan for preventing nuclear explosions.
Prevention of Nuclear Explosion
In order to prevent the leakage of the hazardous radioactive matter, the concept of defense-in-depth is used in modern nuclear power plants (Sevon, T. 2005). As Clery, D. 2011 says, the reactors’ design philosophy now is “defense-in-depth”. This concept involves the use of different technologies and duplicate systems that can not or should not all fail at the same time.
There are many steps or levels of defense-in-depth. Level one of the defense-in-depth involves prevention of failures. However, when the failures still occur, the situation is supposed to be arrested by level two of the defense-in-depth. Level two prevents the failures from evolving into accidents. If this step is not successful, level three of defense-in-depth is used to control the accidents in order to protect the fuel rods from being damaged.
Level four of the concept focuses on accident management by preventing the leak of radiogens into the environment. When these four defense levels fail, level five will help to reduce the effect of the emissions (Sevon, T. 2005). The concept of defense-in-depth supports the prevention of nuclear disasters. Building a second shelter will also be helpful in preventing emissions.
Effects of Chernobyl Disaster and Follow-up Containment
The horrible accident at Chernobyl nuclear power plant occurred 25 years ago. However, the serious consequences of the Chernobyl nuclear disaster are still a major problem for the world. Some areas near the plant, especially Russia, Belarus and Ukraine were substantially contaminated by the large quantities of radioactive materials released from the reactor.
Some of the radioactive materials remained radioactive for a long time and polluted agricultural areas, urban areas, forests and water in the affected countries. Lots of radioactive materials were deposited on the surface of buildings and roads by radioactive rain in urban areas. Radionuclides thus corroded and damaged the buildings and roads.
In agricultural areas, radioactive materials were deposited directly on plants. This damaged huge agricultural land in parts of Belarus, Ukraine, Russia and others parts of Europe. Many grazing animals eat the contaminated plants and became affected. Soil quality was also affected by the radio active materials.
However, the good information is that the level of radioactive materials decreased quickly after the accident due to weathering. Radioactive materials such as caesium destroyed the ecosystem and balance in the forest. The animals and plants in the forest were particularly polluted. This included the forest products like mushrooms and berries. Radioactive materials also contaminated rivers and lakes. Many aquatic animals absorbed radioactive materials quickly, leading to their destruction.
For the 10 days following the accident, the ruptured Chernobyl reactor continued to release 80 tons of radioactive materials and polluted more than 200,000 km2 in Europe. At present, the surrounding environment has not yet fully recovered. Environment researchers said it will take 800 years to eliminate the pollution.
After the accident, Chernobyl Shelter Fund (CSF) was set up in December 1997 to help finance the Shelter Implementation Plan (SIP). The SIP sets out the tasks to be executed for the successful covering of Chernobyl’s unit 4.
The Shelter Implementation Plan will transform the existing temporary structure into a secure and environmentally sound system. Because radioactive materials have long radioactive half-life, they pose great danger to human beings and the environment if their spread is not controlled.
The purpose of “Sarcophagus” was to seal off Chernobyl’s reactor 4 in order to limit the release of radioactive materials and decrease the radioactivity level to normal. The fundamental of “Sarcophagus” was to pour concrete and chemistry materials on the soil and to build a thick concrete-enclosed shield above the destroyed reactor (figure1).
The chemistry materials were used to absorb neutrons and to release CO2, thereby separating O2 and radioactive materials. “Sarcophagus” could seal off the destroyed reactor completely hence reducing some risks. This project cost 14.24 million US dollars. Moreover, many construction workers died after absorbing radioactive materials during the implementation of this project. Thus it can be seen that the government of Ukraine paid a huge price for solving the problems brought by Chernobyl disaster.
The environmental effects of Chernobyl disaster can be seen as the most devastating and long lasting. The initial effects of radioactive fallout were followed by generations of medical problems such as leukemia, thyroid cancer, birth defects, radiation sickness, psychological consequences and genetic defects. To examine these effects, they should be separated into environmental and health consequences.
Reactor 4 released radioactive gases and fuel particles for ten days after the initial explosion. This had a major effect in Europe with the damaging effects being felt mostly in Ukraine, Russian Federation and Belarus. These nations experienced the greatest amount of fallout which contaminated everything including lawns, walls, buildings, plants, animals, roads and squares. The dry areas initially experienced the greatest damage as compared to the wet areas which had the radiation seep through the soil.
There was an immediate contamination of milk and green vegetables within the first two months of the explosion. Consequently, there was as an increase in thyroid cancer, especially in children. However, the effects of these radioisotopes were short lived as their half-life was approximately 9 days. The most unstable and dangerous radioisotopes released were too low to be considered a concern.
The most persistent problem is within the forests. The continued recycling of the ecosystems has allowed the radioactive isotopes to remain within the systems without being contained. Even though there has been a decline in the levels of the radioactive isotopes, it is believed that the problem will last for several decades.
The health consequences that followed Chernobyl disaster can be seen as the most devastating outcome of the explosion as they were long lasting and had the worst effect immediately and after.
Thyroid cancer was the most significant health concern associated with Chernobyl. It was a major outbreak which directly affected all exposed to the radioactive materials and was subsequently passed on to next generations. Even though this problem was initially regarded as a non-Chernobyl related incident by the Scientific Community, it was later reanalyzed as a direct effect of Chernobyl.
There is little knowledge on how radiation causes this health concern. However, as Baverstock (2006, p 1313) states “because of the slow growth of the tumor, it is premature to assume that even lower death rate for current Chernobyl-related cases will be maintained, particularly for cases yet to occur”. An “older age at onset can be associated with a less favorable prognosis” (Baverstock, 2006, p 1313).
Another health consequence was radiation sickness which was more imminent affecting about 150 workers at the time with about 28 dying within a relatively short period, followed by another 20 afterwards. The psychological consequences were quite horrendous.
As Baverstock (2006) claims, they arise from an understandable fear of exposure to an unknown amount of an intangible but potentially dangerous agent, fear for exposed children, mistrust of reassurances from the authorities, and for hundreds of thousands of people, the consequences of forced evacuation from home and land.
For some, the stress from these experiences has precipitated psychological illness; for others, an increased consumption of alcohol and cigarettes; and for still others, dietary changes to avoid perceived contamination.
Some deaths from suicide, cirrhosis, or lung cancer could be regarded as indirect consequences of the accident and the subsequent measures taken. Whatever the view the nuclear industry may have about the irrationality of these consequences, they are real and have an important impact on public health, and so deserve greater attention. (p.1313)
The genetic consequences on workers are still not fully understood due to the limited knowledge. The consequences of leukemia and birth defects have been strongly linked to Chernobyl. However, little evidence and data to support these claims has allowed these issues to go unanswered and left in the dark.
From the above discussion it is apparent that nuclear power generation is a reliable source of energy. However, due to the complexity of the chemical processes involved and the characteristics of materials used, nuclear power generation has turned out to be very dangerous.
Failure to observe safety standards or even natural disasters such as earthquakes can lead to serious nuclear power plant accidents. Such accidents usually have far reaching effects to human beings and the environment due to the release of radioactive materials following the explosion of nuclear reactors.
Of great concern is the fact that it takes several years and significant amount of financial resources to handle such situations. Technical assistance is usually very important in addressing the effects of nuclear accidents. Given the commitment of the affected governments and the advance technology used in response to the Chernobyl nuclear power plant accident, its effects have since reduced significantly.
Consequently, the government of Japan can borrow a leaf from Chernobyl nuclear power plant accident experiences in order to effectively respond to the effects of the Fukushima nuclear accident. The concept of defense-in-depth will particularly be very useful to the government of Japan for its future nuclear power plant constructions. The concept if fully implemented can help in reducing nuclear power plant accidents or the aftermath of such accidents.