Nuclear Power Plant How A Nuclear Reactor Works

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Nuclear Power Plant How A Nuclear Reactor Works

Nuclear Power Plant How A Nuclear Reactor Works

Pressurized Water Reactor - Nuclear Power Plant

Pressurized Water Reactor - Nuclear Power Plant

A. Main Parts of a Nuclear Reactor 1. Fuel • Pellets stacked in long

A. Main Parts of a Nuclear Reactor 1. Fuel • Pellets stacked in long metal tubes (fuel rods). These arranged in bundles in the reactor with space between them for control rods. 2. Moderator • Slows down neutrons so they have a greater probability of colliding with another uranium atom. Usually water or graphite.

A. Main Parts of a Nuclear Reactor (continued) 3. Control System • Control rods

A. Main Parts of a Nuclear Reactor (continued) 3. Control System • Control rods are filled with substances that absorb neutrons (boron or cadmium). These help control the rate of the reaction. 4. Heat Removal System • The reactor must be cooled to prevent overheating and melting of the core. Heat is carried away by water and used for steam production. 5. Radiation Shield • Thermal (steel) shield protects the walls of the reactor vessel from radiation damage. A concrete shield protects the workers from radiation.

B. Disposal Of Nuclear Waste 1. When most usable uranium has fissioned, the “spent”

B. Disposal Of Nuclear Waste 1. When most usable uranium has fissioned, the “spent” fuel assembly is removed from the reactor. 2. Until a long term storage facility is operational (Yucca Mountain, NV? ), “spent” fuel is stored in water pools at the reactor site. 3. Water removes leftover heat and serves as a radiation shield. Underground disposal of radioactive waste (in Finland) Typical water pools for nuclear waste storage

C. Nuclear Meltdown 1. Refers to melting fuel in a reactor when there is

C. Nuclear Meltdown 1. Refers to melting fuel in a reactor when there is an inability to remove heat effectively. 2. Causes include a loss of coolant in the system and/or failure of the reactor to shut down when faulty. 3. If a meltdown does occur, a release of radiation occurs only if there is a major failure in the containment structure (pressure, fire, explosion).

C. Nuclear Meltdown (continued) Chernobyl disaster • Ukraine (Soviet Union), 1986 • Worst nuclear

C. Nuclear Meltdown (continued) Chernobyl disaster • Ukraine (Soviet Union), 1986 • Worst nuclear power plant accident in history • 31 people died during the accident itself, but more people suffered long-term effects like cancer and deformities

C. Nuclear Meltdown (continued) • Fukushima Daini Nuclear Power Plant • Japan, March 2011

C. Nuclear Meltdown (continued) • Fukushima Daini Nuclear Power Plant • Japan, March 2011 • Occurred after the power plant was hit by a tsunami • Although no fatalities were reported after the incident, over 300, 000 people had to evacuate the area, and almost 16, 000 died due to the earthquake and tsunami