N UCLEAR E NERGY Environmental Science Chapter 17 Section 2

F ISSION : S PLITTING A TOMS Nuclear energy The energy within the nucleus of an atom. The forces that hold together the nucleus of an atom are more than 1 million times stronger than the chemical bonds between atoms. Nuclear fission Collisions between the nuclei of uranium atoms and neutrons that cause the nuclei to split. Releases a tremendous amount of energy and more neutrons. Nuclear bomb is an example of an uncontrolled fission reaction. Nuclear power stations control the reactions.

F ISSION : S PLITTING A TOMS

H OW N UCLEAR E NERGY W ORKS

T HE A DVANTAGES OF N UCLEAR E NERGY Nuclear fuel is a very concentrated energy source. Do not produce greenhouse gases. Release less radioactivity than coal-fired power plants.

W HY A REN ’ T W E U SING M ORE N UCLEAR E NERGY ? Building and maintaining a safe reactor is very expensive. Cost is more than $3,000 per kilowatt. Wind power at less than $1,000 per kilowatt. Natural gas plants are less than $600 per kilowatt.

W HY A REN ’ T W E U SING M ORE N UCLEAR E NERGY ? Storing Waste Difficult to find a safe place to store waste. The fuel cycle of uranium produces fission products that remain dangerously radioactive for thousands of years. Fuel, liquids, and equipment from a reactor core are considered hazardous waste. Storage sites must be located in areas that are geologically stable for tens of thousands of years.

W HY A REN ’ T W E U SING M ORE N UCLEAR E NERGY ? Safety Concerns In a poorly designed nuclear plant, the fission process can potentially get out of control. Example: 1986 Chernobyl accident. Most of the reactor’s safety devices were turned off to conduct an unauthorized test. Example: 1979 Three Mile Island in PA. Human error along with blocked valves and broken pumps. Very small amount of radioactive gas escaped.

T HE F UTURE OF N UCLEAR P OWER Nuclear fusion Occurs when lightweight atomic nuclei combine to form a heavier nucleus and release tremendous amounts of energy. Potentially safer than fission because it creates less dangerous radioactive byproducts. Difficult to achieve because of the high temperatures that must be reached for fission to take place.

T HE F UTURE OF N UCLEAR P OWER