I have been graced with another insightful guest blog entry from Claire Scoggin, director of the Wiess Energy Hall at the Houston Museum of Natural Science. The Good the Bad the Energetic: Part 2 In a previous blog entry we discussed what questions we need to ask in order to effectively compare the different sources of energy being presented to us as alternative to oil. As an example I have chosen nuclear energy to analyze. Nuclear Energy Analysis Q: Is it used for electricity or transportation A: Electricity Q: What per cent of our power comes from this source today? A: The United States has 104 commercial nuclear reactors which produce about 20% of our national electricity. There are about 400 nuclear reactors in the world with 33 reactors under construction and 94 ordered. Q: What are the processes involved? A: Nuclear energy is used to produce electricity in much the same way that all electricity is produced - heat energy is converted into mechanical energy, which generates electricity. A large plant generates about a million kilowatts of electricity. The Nuclear Fuel Cycle Nuclear energy has 4 main processes: 1. The uranium ore is extracted from the mine. 2. Conversion, enrichment and fabrication processes prepare the uranium for use in the plant. 3. Inside the power plant, uranium atoms are slowly and carefully split apart in a process called fission, which releases heat energy. This heat energy is used to boil water in the core of the reactor to produce steam. The steam then powers the turbine which in turn generates electricity. 4. Spent uranium in the U.S. is currently stored at the power plant. The U.S. government is trying to build an underground site for storage of the radioactive materials. This Nuclear Simulator Game looks like fun! Q: If the source is for electricity, will it steadily supply the base load or is it intermittent? A: Nuclear energy is continuous so it easily supplies the base load. Nuclear plants are difficult to shut down and restart so they are not used as “peak load” plants. Q: What are the resources required to supply the fuel on a continuous basis (fossil fuels, biomass, biomass, wind, solar etc)? A: Resource: Uranium or any combination of thorium and uranium. Known uranium sources are expected to last the world for about a century at the current rate of usage. Availability of resource: Uranium is found in rocks and is abundant worldwide with the largest deposits in the Rocky Mountain regions of North America. It requires about 200 tonnes (440,800 pounds) of U308 per year to keep a large nuclear reactor running. Cost of resource: In 2008 the average cost of uranium UX-U3O8-SPT per pound was $106.90 and expected to be $91.90 in 2009. The cost of the fuel is not a major factor in the price of electricity produced by nuclear power plants so a sharp rise in the cost of uranium would have a small effect on the cost of the electricity. Procedures for producing resource: Uranium is mined by removing the ore, or rock, from the ground in underground or open pit mines. Then the rock is taken to uranium mills where the uranium is taken from the rock by leaching with a variety of chemicals. The uranium is made into cakes that are yellow so they are called “yellow cake." Our relationship with the nations providing the resource if a high percentage cannot be provided domestically Since uranium is easily mined in the U.S. we can assume that we will not have problems with obtaining the resource. Current and future global competition for resource Uranium is also mined in other mountainous regions around the world so competition will not be a problem. Q: What is the cost of production - per KWH produced? A: Once the reactor is built, the cost of generating electricity from a nuclear plant is about 0.4 cents a kilowatt-hour. Another estimate of 2.86 cents per KW- Hr includes the cost of building the plant, feedstock, waste disposal projected costs and decommissioning costs. It does not include interest on the money borrowed to build the plant. Q: What is needed to produce electricity from this source? A: The following is a list of what is needed. Front end costs to build electricity production facility Nuclear power plants are relatively expensive to build and the cost may have doubled in the past 2 years to $5-10 billion for a one reactor plant to as much as $24 billion. The need to use special materials and to incorporate sophisticated safety features and back-up control equipment raises the cost of building a nuclear power plant significantly higher than for coal or gas-fired plants. Once the plant is built the operating cost is much the same. It is estimated that new reactors would cost up to $6,000 per kilowatt of capacity to build. Time required to build facility It is said to be possible to build a facility in 4-5 years and 2 more for licensing and approvals. Most believe the numbers are double that. Are building materials domestic or foreign? Nuclear power plants are built of mostly concrete and steel which are easily available although the economic growth of India and China is rapidly increasing its demand. Other resources required to process Most nuclear plants are built on the shores of oceans, lakes and rivers in order to use the water to absorb the heat left after powering the generator. The amount of water needed varies according to the design of the plant but it is huge amounts of water, most of which is reused. Some estimates are 4 million gallons of water a day. Ability to shut down and restart plant Nuclear plants are very difficult to stop and restart. Every 1-2 years most reactor must be shut down to be partially refueled. Maintenance – speed of equipment deterioration The Nuclear Regulatory Commission will license a plant for 40 years. After that they can renew their license or decommission the plant. Decommissioning means shutting down the plant and taking steps to reduce the level of radiation so that the land can be used for other things. The NRC requires that the decommissioning process can take no more than 60 years. Personnel needed and training involved A nuclear power plant employs about 1,000 people. Engineers and technicians for reactors require 4-5 years of training. Universities are re-establishing nuclear training programs and bachelors degrees and the PHD programs. Cost to rebuild and how often this will be necessary. A nuclear power plant is expected to last for about 40 years. New technologies are making it possible to prolong that time. Q: Are there geographic limitations? A: Most types of nuclear plants are built near a large water source in order to use the cooler water to chill the hot water used to produce steam. Q: is the resource near the market and distribution facility? A: Uranium mines are not near the nuclear plants so the ore must be transported long distances by highways, trains or waterways. Containers have been designed to carry dangerous nuclear materials that are capable of withstanding enormous impact. Look for Part 3 soon which, will cover the environmental effects of nuclear energy.