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RADIATION AND THE PRODUCTION OF ENERGY
It must be obvious to everyone that it requires energy just to live. Energy from the sun keeps the earth warm, enables plants to grow. The burning of coal, oil, or natural gas produces electricity which, in turn, heats, lights, and air conditions our homes; cooks our food; and operates our television receivers. Petroleum is required to run our automobiles, trains, and aircraft. Name any necessity or luxury of life, and it will require energy to make that item, to operate it, and to maintain it. The more technically advanced the country and the higher the standard of living, the more energy will be demanded.
Energy needs are greater today than yesterday, less than tomorrow, and are roughly in proportion to the size of the population. Somehow this message must penetrate our thinking. Even as this is written in June -- before the Washington summer has really started -- we have twice run out of electrical energy, and our operating voltage has had to be lowered (usually referred to as a "brownout") to prevent a complete power failure and "blackout" because of overloading our local electrical supply system. For a day or two, now and then, this is a tolerable but risky expedient. However, it can be harmful to much of our precious electrical equipment and cannot even be considered as a possible long-range remedy to our power shortage. The brownout lowers the power requirement by only four or five percent -- barely enough to keep the circuit breakers from tripping.
3-1 Electrical power needs of the future. At the current rate of growth, our population will increase another four or five percent in roughly five years, and this will use up the energy that was saved by lowering the voltage. Unless we are in a much more secure energy situation at the end of those years, we will be in deep trouble. As soon as the words "energy shortage" are mentioned, a substantial part of our population volunteers its standard series of answers to all energy problems. A few of these will be noted so as to prepare a background for appropriate answers in the discussions to follow.
Some of the more practical suggestions are given below.
In addition to the various uncertainties touched upon above, the public should be aware that many years of planning are required are required for the completion of any kind of power plant. The construction of an electricity-producing power plant, from drawing board to power on the line, may take as much as ten to twelve years, not counting the additional time that may be is lost because of protests by an often misinformed public. This "not in my backyard" (NIMBY) phenomenon has thwarted plans for all sorts of facilities, including solar, oil, coal, and nuclear power plants.
We are now facing numerous localized power shortages, and yet, for all practical purposes, we have no new central station plants for producing electricity on the drawing board. THINK ABOUT IT!
3-2 The nuclear alternative. It is possible that the development and control of nuclear power for the generation of electricity has been achieved just in time to save the world, for quite a while, from disastrous impacts of unbounded population growth and the depletion of naturally occurring raw materials.
The production of electricity through nuclear reactors is now a proven economic source of energy, and in this country, can be done with complete independence from foreign sources of raw materials and outside political influences. Nuclear-produced electricity has proven to be a godsend to smaller, developing countries as well to those with developed technological economies. For example, as of the early 1990's, England, whose supply of coal is dwindling, has 37 nuclear power plants and 1 more in development. Canada is making extensive use of nuclear-produced electricity in spite of having ample deposits of coal. France, a country with very limited coal or oil, is working towards a goal of producing approximately 80% of its electricity in its nuclear power plants. As of 1990, it was meeting 75% of its demand with nuclear generation.
The operations of nuclear power plants themselves in this country give off no toxic emissions of either a chemical or a biological nature. While guardedly accepting the statements just made above, the general attitude of the public seems to be, "yes, but ---", and then they raise a series of questions which have to be answered. Providing understandable answers to these questions has been one of the objectives of this book. Answers to most of the usual questions are given below, and most of these answers are based on very firm and well established facts. Any areas of uncertainty in the mind of this author, will be noted.
As already shown on the pie chart, the average annual radiation exposure to members of the U.S. public resulting from the generation of electricity by nuclear power, is in the order of 0.3 millirem, This is only about a tenth of one percent of the average exposure from the naturally occurring radiation to which everyone in the public is subject. It includes the entire nuclear power program, involving the mining, milling, and refining of the uranium for fuel, construction of the fuel elements, operation of the power reactor, handling and transportation of low- and high-level nuclear wastes, fuel reprocessing, and the ultimate disposal, storage, or recycle of waste materials.
3-3 Wastes from nuclear power generation. The most frequently voiced objections to nuclear power relate to the disposal of the radioactive wastes resulting from plant operations. Knowledgeable people recognize this as an important factor, but one for which satisfactory solutions exist. The fact that the public is inadequately informed about energy generally, and radiation in particular, has substantially contributed to the present impasse regarding nuclear waste control and disposal.
Parenthetically speaking, the handling and disposal of any waste material, be it of industrial or household nature, is always a matter of great contention even when radiation or radioactive materials are in no way involved. Most practical disposal plans for all types of community wastes attempt to minimize the transportation distance between the sources of the waste and its ultimate disposal site. The problem is almost always aggravated by growing amounts of non-biodegradable waste in the form of plastics.
There are basically two forms of radioactive waste which have to be considered. The first of these is the so-called "low-level waste", which comes from industrial processing, hospitals, laboratories, and similar facilities. The second is "high level waste" which is primarily made up of the used fuel elements that must be replaced periodically in operating power reactors, These elements are currently being held in storage at each reactor site.
3-3.1. Transportation of nuclear wastes. The first problem with either kind of waste involves transportation from the point of origin to point of storage or disposal. Means of containment and movement, as well as the integrity of the containers, have been adequately tested under the most serious and extreme accident conditions. Small-lot shipments are most likely to be made by specially designed trucks used on the general highways. There have been a few accidents involving these shipments, but in the few cases where the containers were disrupted, the escape of radioactive material was minor and sharply limited to the site of the accident -- generally within a circle of less than 50 feet radius. There has been no appreciable escape of gaseous or airborne particulate radioactive material. The extent of any spill can be quickly and positively determined by radiation instrumentation carried with the shipment. The general impact of such a spill would normally be many times less than that of the rupture of a single railroad tank car of any of many kinds of toxic chemicals, common incidents which sometimes require mass evacuations. The probability of release of radioactive material in such highway accidents is extremely small, and should not be considered an impediment to the use of nuclear reactors of any type and power.
The transportation of used reactor fuel rods involves much more complex engineering problems, but it is believed that all of these problems have been adequately identified, examined, solved and tested. The fuel rods are contained in heavily constructed steel cylinders, lined with many inches of lead, sufficient to prevent any appreciable amount of radiation passing through the container walls to the point of exposing anyone standing immediately next to it -- including the truck crew. This system has been tested, at least twice, by placing a fully loaded cylinder upon a multi-axle, flat bed trailer, placed immediately across a railroad track at a grade crossing. From a short distance away, two large-sized diesel-electric locomotives, assisted by several rocket engines, were driven into the side of the nuclear fuel tank and trailer, striking it at a speed in excess of 100 miles per hour. The tanks were thrown a considerable distance and high into the air, but failed to develop any leakage or structural damage. Radioactive gas contained in the dummy load failed to escape anywhere. The locomotives fared less well.
3-3.2 Storage of nuclear wastes. The last step in the waste disposal chain is that of permanent storage - most probably underground. To meet this challenge the National Academy of Sciences was asked to set up a special group to examine the total problem and to recommend any needed solutions. This prestigious group included some of the world's leading geologists, hydrologists, mining engineers and authorities on earth science. After several years of study, they designated twelve storage locations in the United States, located at various depths underground and in various kinds of rock, earth, or salt. One of the prime requirements was that in the event of leakage of any of the storage containers, radioactive contamination could not seep into the underground water supplies upon which the population must depend. The twelve sites were arranged in the order of highest certainty of security, extending over a period of 100,000 years.
The waste material will be stored in a series of tunnels, located at levels from several hundred to several thousand feet below the surface, depending upon the ground-water conditions. The radiation safety requirements, specified by the Environmental Protection Agency, are that levels of radiation that might extend up through the earth to the surface, must not exceed one percent of the annual radiation level of the natural background at the boundary line of the site under which the material is stored. The Department of Energy extended this, beyond the EPA requirement, to levels not exceeding a tenth of one percent of the natural background radiation levels at the surface. Incidentally, on the average, this would amount to a possible exposure of somebody living on the surface, above the storage site for one year, to a level of less than four-tenths of a millirem. This is less than the daily variation in the background levels at any point on the earth.
Here, it must be realized that the designers of this storage program have extended their requirements far beyond any practical experience of man. Testing the accomplishment of the required objectives can be carried out at any time, quickly, and easily, with existing instrumentation. It does, however, represent the culmination of an enormous amount of study and past experience bearing directly on the problem. Final judgment of the achievement of the goals, is ultimately made by the informed scientific and engineering community.
It has been asked why we do not wait until we can carry out the necessary experiments to prove, rather than just predict, the security of the storage plan. The shortest conceivable time, in which to carry out a reasonably conclusive test, would be on the order of two- to three-hundred years. By that time all of our supply of oil would be gone, and more than half of the coal that we now believe available to us would have been consumed. When we change our time-frame to thousands or tens of thousands of years, we have to consider the possibility, however remote, of major earthquakes and earth movements, the covering of at least the northern part of the United States by a glacier, and even a collision between the earth and a huge meteorite that could demolish half of the country. Recognizing this long term uncertainty and the short-term possibilities for change in the next few hundred years, disposal site designs provide for the storage of radioactive material in such a manner that, if there develops some leakage of a serious nature, the radioactive material can, if necessary, be removed either temporarily or permanently to permit examination and rectification of the cause of the problem.
The answer to the question of long-term, high-level waste storage is that we have, as of today, identified sites believed suitable for holding the waste resulting from seventy years operation of all the American reactors in being and predicted for the future.
The first site has been selected, a tuff-rock deposit in Nevada -- Yucca Mountain -- and, after considerable political wrangling, environmental and engineering studies are proceeding. Decisions as to which of the sites will be used are generally non-technical, political issues It is hoped that this book will help allay many genuine fears by providing a better understanding by the public of the overall radiation safety issues involved in radioactive waste management.