At this point, there was little chance that the reactor would disastrously explode again. Attention now turned to long-term containment of the radioactive wastes produced by the Chernobyl accident. Highly radioactive debris was buried in over 800 temporary burial sites, diminishing the immediate risk to the population of Ukraine, but potentially endangering future generations and the long term health of underground aqueducts. By the end of 1986, the extremely radioactive reactor core was encased in a large concrete-and-steel “sarcophagus” (”Chernobyl Accident”). This sarcophagus was built–using the remaining structural components of the unit four building for support–as a series of rising sections completely enclosing the reactor area. In addition, a huge concrete partition was erected to separate the unit four building from the adjacent unit three complex. Finally, over three hundred sensor devices have been embedded in the entombed reactor to monitor internal temperature and radiation levels (”Nuclear Power” 73-75).
After the Chernobyl disaster, the international community became increasingly concerned with older “Soviet-designed nuclear power reactors operating without basic safety features such as emergency core cooling systems, protective structures to contain radioactive releases in the event of an accident, and skilled personnel” (GAO/N8IAD-92-28 4). Chernobyl has increased international debate about making the International Atomic Energy Agency s standards of safety mandatory for all nuclear powers. However, as most nations–including the United States–do not want national sovereignty infringed by international organizations, adoption of new standards and their enforcement have been severely limited (GAO/N8IAD-92-28 4).
While several measures have been devised to clean-up the immediate effects following the Chernobyl disaster, the most important issue–that of ensuring safe nuclear power for the future–has yet to be addressed. Nuclear power advocates must realize that another Chernobyl disaster may be the total death knell for practical uses of nuclear energy for at least the next generation. Therefore, engineers, scientists, and politicians must ensure that all new nuclear reactors meet highly stringent safety requirements, while old, obsolescent reactors are quickly and systematically retired from active service. As the scientific community has come to a general consensus that the world will soon be plagued with acute fossil fuel shortages, the most immediate solutions appear to lie with nuclear power. Ironically, the most long-term solution to the energy needs of the world also appear to lie with an advanced yet highly different form of nuclear energy. In the next section, a few of the most promising nuclear technologies will be mentioned.
One of the most promising nuclear technologies that could be implemented almost immediately is the so-called “inherently safe” nuclear reactor. In this type of reactor, the core is built below the ground, next to a large source of water. Therefore, if an accident were to occur, the core could instantly be flooded, preventing a Chernobyl-type explosion or a Three Mile Island type meltdown. Also, a reactor of this type would use negative power-reactivity feedbacks to keep it working in normal operating parameters. This means that if there were a leak in the reactor, the loss of water would cause fewer neutrons to be absorbed by the fuel elements, causing the overall power output of the reactor to reduce. In this way, as coolant decreases, the power output of the reactor automatically adjusts to a safe level. This contrasts with the positive power-reactivity feedback systems in the RBMK reactor type used at the Chernobyl plant. When the plant began to lose coolant, it increased power, causing a massive and uncontrollable explosion (”Energy Conversion”).
The energy that powers the sun is the ultimate goal for nuclear physics: fusion. In a nuclear fusion reactor, two light elements–usually two different forms of hydrogen, deuterium and tritium–are combined to form a single, heavier element. In the process, however, some of the mass of each light particle is directly converted to energy. Because matter contains so much energy per unit of mass, a self-sustained nuclear fusion reactor would provide mankind with a virtually limitless supply of energy. Moreover, hydrogen the most likely candidate to power a fusion reactor is the most abundant element in the universe and is readily available for a nuclear reactor. However, a self-sustained fusion reaction has proven extremely difficult, mainly because fusion requires that a plasma of several hundred million degrees Celsius be held at a distance away from the reactor walls at a density sufficient to allow the plasma to be self-sustaining. In other words, the plasma must have enough average transitional kinetic energy to kindle a fusion reaction in particles ejected sometime after the initial ignition. Fusion has been successfully demonstrated in the laboratory despite the fact that it currently takes more energy to start fusion than can be obtained from the short pulses the reactors operate in (Knief 506-510).
Conclusion
In this incredible era of expanding knowledge and technology, man has been blessed with the power to create and destroy with unbelievable efficiency and ruthlessness. But with power comes responsibility, a responsibility all too neglected by even the most astute and learned within society. Because disasters such as Chernobyl are the pinnacle of long chains of carelessness, they serve to highlight this neglect and show how apparently infallible technologies can go disastrously wrong. Though Chernobyl was a tragedy in the worst sense, it forced a complete reevaluation of the nuclear industry and may prevent further such accidents. However, history has shown time and time again that man has an incredibly short memory and usually reverts back to old-habits, regardless of the cost. It can only be hoped that the next century will be dominated by people of vision; those who would dare to dream the impossible, and then make it reality. These people must embrace nuclear fusion as the only energy source capable of providing humanity with a long term solution to its energy requirements. The old fears, hatreds, and ignorance of nuclear power must be erased, paving the way for a future dominated by this clean, awe-inspiring source of energy
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