11.2 Nuclear Energy Unit 11: Energy May 25, 2009 Unit 11: Energy

Nuclear Fission Nuclear energy is the energy that exists in the nucleus of the atom. Splitting the atom releases energy. July 31, 2019 Unit 11: Energy

An intact 235U Nucleus is about to be struck by a neutron.

When struck by a neutron, the 235U nucleus splits, forming new elements. Releasing neutrons and energy.

3. The released neutrons, Strike other 235U nuclei.

The nuclei split and release neutrons and energy.

Nuclear Power Nuclear fission releases a lot of energy. An uncontrolled release of energy is an atomic blast. July 31, 2019 Unit 11: Energy

Controlled Reaction Nuclear power works to heat energy. The heat of the energy is what causes the water to heat and turns the turbine. Nuclear energy is a very rich source of energy. July 31, 2019 Unit 11: Energy

How a Nuclear Power Plant Works 2. Superheated water is pumped to a heat exchanger, which transfers the heat of the primary circuit to the secondary circuit. 4. Steam is directed against a turbine, setting it in motion. 5. The turbine sets the generator in motion, generating electricity. 3. Water in the secondary circuit flashes into high-pressure steam. 1. Energy released be the nuclear reaction heats water in the pressurized circuit to a very high temperature.

Advantages of Nuclear Energy Uranium is the most common nuclear fuel. One gram (the weight of a paperclip) produces as much fuel as 3.5 metric tons of coal. Power Plants can go years without refueling. Nuclear power plants do not give off greenhouse gases. July 31, 2019 Unit 11: Energy

Disadvantages Nuclear power produces radioactive waste. Each nuclear power plant must store its own spent fuel. Nuclear power is expensive. Large Complex Many safety guidelines July 31, 2019 Unit 11: Energy

Chernobyl On April 25 1986 5:23 p.m. eastern time a reactor at the Chernobyl plant, Ukrainian Soviet Socialist Republic, exploded. More explosions and fire sent a plume of highly radioactive fallout into the atmosphere and over a large geographical area. Four hundred times more fallout was released than had been by the atomic bombing of Hiroshima. Chernobyl http://www.youtube.com/watch?v=5HLkD57pJhY July 31, 2019 Unit 11: Energy

Energy Sources Nuclear fusion is the process by which charged atomic nuclei join together to form a heavier nucleus. It is accompanied by the release of energy. The fusion of two nuclei with lower mass than iron (which, along with nickel, has the largest binding energy per nucleon) generally releases energy while the fusion of nuclei heavier than iron absorbs energy; vice-versa for the reverse process, nuclear fission. In the simplest case of hydrogen fusion, two protons have to be brought close enough for their mutual electric repulsion to be overcome by the nuclear force and the subsequent release of energy. July 31, 2019 Unit 11: Energy