Tuesday, December 5, 2006

economy of nuclear power generation in Iran

Nuclear power generation has been an attractive energy source since 1950s. The economic feasibility of this sort of energy took a turn for worse in the mid 1970s. In order to answer the economic feasibility of nuclear power generation on 21st century especially for a country with the economic situation of Iran, we need to compare the cost and the feasibility of such a project, with the ones already built and operated in the United States today. Because the United States has built the most efficient and safest plant in the world, and the length of experience with such technology is the oldest. There are several facts to be considered that for one the last nuclear power plant was built in the United Stated in 1973(onclick="BLOG_clickHandler(this)" class="blsp-spelling-error" id="SPELLING_ERROR_0">Rancho Seiko, near Sacramento, California), and the same reactor was decommissioned in 1988. Since then, no nuclear power plant has ever been built or purposed for construction. On the contrary, close to ten power nuclear plants have been shut down and are in the process of decommissioning (the most recent, Zion Nuclear Power plant in Illinois).

A nuclear power plant in design and running is much different and more complex than a fossil or gas power plant. With Nuclear power plants, the cost of electricity is largely determined by capital costs (specifically, the interest charged on the money used to build the plant) and not by the fuel cost. Although this is the biggest advantage of nuclear power plant over other plants, but negligence in the operation of nuclear power plant is catastrophic to people and environment. For this reason, great care and design must be used to operate and maintain nuclear power plants. This in turn calls for placement of more economical restraint on the cost of building a nuclear power plant. Another significant drawback with nuclear power plant is the amount of radioactive waste generated by the plant, which need to be deposited and maintained for generations to come.

Although the exact details of Iran’s new power plant has not been made public, but one assumes that they are in the path of building a light water reactor fueled with natural uranium. Typical nuclear power plant with the index of US economy is at about 1 to 2 billion dollars. Therefore, the cost figure of Iran’s nuclear power plant estimated at 1.5 billion dollars is a figure that could be trusted to complete the reactor and fuel it to put into operations. Every nuclear power plant is divided into systems. A typical light water reactor is consists of almost two hundred systems, which seventy five percent (75%) of the systems are practically are safety systems. This is significant, since we are dealing with prevention of all kinds of accidents from core meltdown to the release of radioactive materials and gas into local water systems and food chains. Therefore, as a rule of thumb it is estimated that the cost of operation to be about 1% of its capital cost per year, which in most conservative estimate, it should cover the cost of routine maintenance, replacement parts, frequent testing of safety systems, payroll, and expert analysis to operate the reactor.

As for the fuel, the total, world-wide requirements for uranium over the years depend on the growth of installed nuclear capacity and on the mix of reactor types and fuel cycles that is adopted with the passage of time. It is impossible; of course; to predict accurately future nuclear electric capacity because so many uncertain factors enter into decision to construct new nuclear power plants (the growth in world population, the state of world economics, the climate of international politics – wars and other political confrontations- the availability of competing energy resources, and so on). Therefore, prediction of installed nuclear capacity made today can appear ludicrous only a few years later. In late 1970’s, several studies of uranium supply and demand have been carried out, specially in connection with the International Nuclear Fuel Cycle Evaluation exercise. One conclusion was that new resources of production would be needed before the end of century, perhaps as early as the 1990s to keep fueling the current nuclear power plants. Since precise prognostication of nuclear capacity can not be made, it has become a common practice to give projection in terms of high and low capacity projections. Therefore, the future capacity by no means guaranteed, whether sufficient uranium will be available to fuel the expanding world nuclear capacity is an issue of continuing controversy among experts.
Most of the uranium used in nuclear power plants today and up to the year 2025 will undoubtedly come from deposits that are now or could be exploited at a forward cost (forward cost is a specialized term used to describe the economic availability of uranium resources. It includes the estimated costs of developing, building, and operating uranium mines and mills at the sits of established uranium resources. It does not include the cost of exploration, the cost of money (interest charged), marketing costs, profits, and so forth, which contributes to the price of uranium. As a rule of thumb, the actual market price of uranium is twice its forward cost). The forward cost, in 1978 U.S dollars is about one hundred and thirty (130) dollars per kilogram of uranium. In twenty five years span (from 1978-2003) average salaries and prices has increased by 350 percent. Therefore, the forward cost in 2003, is roughly four hundred (450) dollars in 2003. In a light water thermal reactor, the consumption rate of uranium is about 1.23 grams per day per one megawatt of power. Therefore, in order to generate twelve hundred (1200) megawatt of power per day, one and half (1.5) kilograms of uranium per day will be needed.

Radioactive waste disposal is another challenging cost and problem facing nuclear power plants operations. Radioactive waste is classified into four categories. Two major categories are 1) High level waste consists of spent fuel, and 2) Transuranic waste generated by fuel reprocessing, and manufacturing of nuclear weapons. The vast majority of fission products are short lived, but among them there are three isotopes of Strontium (90), Yttrium(90), and Cesium(137), have half-lives of about thirty years. But the problem lies with transuranic waste, although not as much radioactive, but the half-life of its Plutonium (239) is about twenty four thousand (24000) years. In spent fuel of a light water reactor, the transuranic waste radioactivity will exceed the high level waste after approximately seven hundred (700) years. Most of high level waste is stored in liquid form in large tanks. Then the waste (the spent fuel assemblies) is placed in proper containers and buried in some pre-determined geological facilities permanently. This is the case if the fuel is not reprocessed. Reprocessing is a procedure that reduces the volume of the waste, and it will become more manageable, but at greater cost. In terms of the cost, Baltimore Gas and Electric Company which owns number of nuclear power plant had horizontal storage modules designed along with on-site facilities to store their nuclear waste. In 1989, the design and construction of casks estimated at twenty four (24) million dollars, the cost of storage at sixty two (62) million dollars, and the cost of operating and maintenance of the storage at 2.5 million dollars per year. This is not included the cost of reprocessing.

The life expectancy of a nuclear power plant is estimated to be 30-40 years (This is the period that nuclear regulatory Commission issues operating license for nuclear power plants before they go to major overhaul). In average, every nuclear power plant is in operation only 274 days out of 365 days per year ( the plant is inoperable 18 days per year for refueling, 45 days per year for repair to nuclear portion of the plant, and 18 days per year for repair to non-nuclear portion of the plant). As the case with the Iran’s nuclear power plant which is operating at 1200 Megawatt electric per year, it will produce a total of 10-13 million Megawatt during its life span. The total fuel usage for the plant is approximately 12330-16440 kilograms of uranium, the cost of the plant is fixed at 1.5 billion dollars, the cost of operation and maintenance is at best estimate 600 million dollars, the cost of waste treatment is approximately 100 million dollars. Therefore, the cost of generation of electricity per one Megawatt is roughly about 190.16 dollars, which per kilowatt is $ 0.19016.

This cost is a generation cost to utility industry. The generation of electricity in the United States and the world is in the average range of 0.014 dollars per kilowatt (1.4 pennies), which is sold to customers at average price of 0.084 dollars per kilowatt (8.4 pennies). This is in turn, when the cost of electricity in Iran is presently comparable to the world.

With the help of nuclear power, the average price of electrical generation conservatively will be almost fourteen times (14) more than what is normally costing at present time. With the progressive inflation rate in Iran, in five years, this rate will be over twenty five (25) times of the present cost to the average consumer in Iran.

Prepared by: Mehrdad Moin
Education: MS in Nuclear Engineering,

No comments: