1039 GW Power Plant Equivalent 104 Nuclear 100 Hydro = 204 Clean Energy Remaining 53.3… 39 Wind 11 Biomass 2.5 Geothermal 0.8 Solar 407 Natural Gas 316 Coal 56 Oil 2.7 Methane = 781.7 GW from Fossil Fuels

1039 GW Capacity in the US 10.010% Nuclear 39.172% Nat. Gas 9.625% Hydro = 19.6% Clean Energy Remaining 5.130%… 3.754% Wind 1.059% Biomass 0.241% Geothermal 0.077% Solar 39.172% Nat. Gas 30.414% Coal 5.390% Oil 0.260% Methane = 75.236% from Fossil Fuels

How Nuclear Power Plants Work

Uranium Is Mined and Refined Uranium is mined from the earth through surface, underground, or solution mining. In the United States, nearly all uranium is solution mined. A solution is injected into the uranium ore deposit then pumped out. The uranium then is separated from the solution. Uranium also is obtained as a by-product in the production of phosphate, sulfur, vanadium, copper and gold. After the uranium is mined, it must be refined through further processing.

Uranium Ore  Uranium hexafluoride  Gas  Solid Drums of uranium ore concentrate are shipped to a conversion plant, where they will be cleansed of impurities and converted to uranium hexafluoride, shown here in cylinders. The uranium hexafluroide is heated to become a gas, then cooled and condensed to a solid.

Enrichment Concentrates the Uranium Isotope These are uranium centrifuges—one method of enriching uranium. Uranium contains two kinds—or isotopes—of uranium. The enrichment process concentrates the isotope that is most useful in energy production. Enriched uranium will operate a nuclear power plant, but is not concentrated sufficiently to make a nuclear bomb.

Uranium Is Formed Into Hard Ceramic Pellets Finally, the uranium hexafluoride is shipped to a fuel fabricator, where it is manufactured into solid ceramic pellets, about the size of the end of a finger.

Fuel Rods Filled With Pellets Are Grouped Into Fuel Assemblies The pellets are inserted into long metal tubes called fuel rods. The fuel rods are made of zirconium—which resists heat, radiation and corrosion. The rods are bundled together into fuel assemblies, which are placed in the reactor.

Nuclear Energy Comes From Fission When a nuclear power plant starts up, neutrons are released. When they strike the uranium atoms in the fuel pellets, the atoms split—or fission.

Heat Produces Steam, Generating Electricity Turbine Generator Steam produced Electricity This process continues in a chain reaction, producing a great deal of heat. It is this process—creating heat through the splitting of atoms—that turns water to steam. The steam is moved from the reactor to turn the turbine-generator, which makes electricity. All radioactive water stays within the reactor system and is not released into the environment.

Nuclear Energy Comes From Fission When a nuclear power plant starts up, neutrons are released. When they strike the uranium atoms in the fuel pellets, the atoms split—or fission.

PRESSURIZED WATER REACTOR (Westinghouse)

Pressurized Water Reactor

BOILING WATER REACTOR (General Electric)

PRESSURIZED WATER REACTOR (PWR) BOILING WATER REACTOR (BWR)

Boiling Water Reactor

Nuclear Power Plants in PA Beaver Valley (PWR) Limerick (BWR) Peach Bottom (BWR) Susquehanna Steam Electric Station (BWR) Three Mile Island (PWR) (All sites have two reactors, although the Unit 2 reactor at TMI was dismantled after its malfunction – March 28, 1979)

Westinghouse AP1000 Control Room

Westinghouse AP1000 Control Room

Safety Is Engineered Into Reactor Designs Containment Vessel 1.5-inch thick steel Shield Building Wall 3 foot thick reinforced concrete Dry Well Wall 5 foot thick reinforced concrete Bio Shield 4 foot thick leaded concrete with 1.5-inch thick steel lining inside and out Reactor Vessel 4 to 8 inches thick steel Reactor Fuel Weir Wall 1.5 foot thick concrete Nuclear power plants use a series of physical barriers to make sure radioactive material cannot escape. In today’s water-cooled reactors, the first barrier is the fuel itself: the solid ceramic uranium pellets. Most of the radioactive by-products of the fission process remain inside the pellets. The pellets are sealed in zirconium rods, 12 feet long and half an inch in diameter. The fuel rods are placed inside a large steel reactor vessel, with walls 8 inches thick. The vessel is surrounded by 3 feet of concrete shielding. At most plants, a leak-tight steel liner covers the inside walls of the containment building. The containment building is a massive, reinforced concrete structure with walls 4 feet thick.