Nuclear power plants
Nuclear power plants USMAN IQBAL
Nuclear Power TodayProvides almost 20% of worlds electricity (8% in U.S)69% of U.S. non-carbon electricity generation More than 100 plants in U.S.None built since the 1970s200+ plants in the EuropeLeader is FranceAbout 80% of its power from nuclear
Countries Generating Most Nuclear Power Countries Total (MW) USA 99,784 France 58,493 Japan 38,875 Germany 22,657 Russia 19,843 Canada 15,755 Ukraine 12,679 United Kingdom 11,720 Sweden 10,002 South korea 8,170
History of Nuclear Power
OriginsAfter World War II, development of civilian nuclear programAtlantic Energy Act of 19461954: first commercial nuclear power program
History1938- Scientists study nucleus of uranium 1941- Manhattan project 1942- Controlled nuclear chain reaction 1945- U.S use two atomic bombs on Japan1949- Soviet develop atomic bomb1952- U.S test hydrogen bomb1955- First U.S nuclear submarine
Early BeginningsAtomic Energy Commission (AEC) established by Congress in 1946 as part of the Atomic Energy Act
AEC authorized the construction of Experimental Breeder Reactor I ( EBR-1) at a site in Idaho in 1949
in August of 1951, criticality (a controlled, self-sustained, chain reaction) was reached using uranium
A football sized core was created and kept at low power for four months until December 20, 1951
Early Beginningspower was gradually increased until the first usable amount of electricity was generated, lighting four light bulbs and introducing nuclear generated power for the first time
In 1953, the EBR-1 was creating one new atom of nuclear fuel for every atom burned, thus the reactor could sustain its own operation
With this creation of new cores, enough energy was created to fuel additional reactors
A few years later, the town of Arco, Idaho became the world's first community to get its entire power supply from a nuclear reactor
This was achieved by temporarily attaching the towns power grid to the reactors turbines
Working principle The conversion to electrical energy take place indirectly, as in conventional thermal power plants; the heat is produce by fission in a nuclear reactor(in a coal power plant it would correspond to the boiler) and given to a heat transfer fluid- usually water(for a stander type light water reactor). Directly or indirectly water vapor-steam is produce. The pressurized steam is then usually fed to a multi-stage steam turbine. Steam turbines in western nuclear power plants are among the largest steam turbine ever. After the steam turbine has expanded and partially condensed the steam, the remaining vapor is condensed in a condenser.
Working principle The condenser is a heat exchanger which is connected to secondary side such as a river or a cooling tower. The water then pumped back to the nuclear reactor and cycle begins again.The water steam cycle is corresponds to the Rankine Cycle
Nuclear reactorsA nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. The most common use of reactors is for the electric generation and for the propulsion of ships.The nuclear reactor is the heart of the plant. In its central part, the reactor cores heat is generated by controlled nuclear fission. With this heat, a coolant is heated as it is pumped through the reactor and thereby removes the energy from the reactor.Heat from nuclear fission is used to raise steam, which runs through turbine, which is turn power either ships propeller or electrical generator.
NoteSince nuclear fission creates radioactivity, the reactor core is protected by a protective shield.This containment absorbs radiations and prevent radioactive material from being released into the environment.In addition, many reactors are equipped with a dome of concrete to protect the reactor against external impacts.In nuclear power plants, different types of reactors, nuclear fuels, and cooling circuits and moderators are sometime used.
Nuclear Fission from Slow Neutrons and Water Moderator
Inside a Nuclear ReactorSteam outlet
Steam turbine The object of the steam turbine is to convert the heat contained in steam into rotational energy.The engine house with the steam turbine is usually structurally separated from the main reactor building.
Energy Taken out by Steam Turbine
Safety valve The pressure in the reactor pressure reactive vessel at an incident, to limit upward, two independent valves are available. The pressure relief prevents the bursting of pipes or reactor.The valves in their capacity designed so that they can drive all of the supplied flow rates with little increase in pressure.
Nuclear proliferationMany technologies and materials with the creation of nuclear power program have a dual-use capability in that they can use to make nuclear weapons if a country is chose to do so.When this happen the nuclear power program become route leading to the atomic bomb or public annex to a secret bomb program.The crisis over Irans nuclear activities is case in point.
Uranium MiningThere are three main methods:
Open pit mining
In Situ Leaching (ISL)
The Case of the Olympic Dam Mine
Underground MiningOlympic Dam mine is located in South Australia
Most of the mines profit actually comes from the copper that they mine as well
Tunnels are dug into the earth, where ore is extracted
The ore is crushed into a powder, then soaked in a lake. The impurities precipitate and the rest is dried by heat.
Ya Got Trouble.
The Western Mining Corporation (WMC) is owned by BP
Lake uses an intense amount of water
Rabbit popluation has crashed as a result of drinking from the lake
In Situ LeachingWells are drilled into aquifers, the water is removed, and a solvent, such as hydrogen peroxide, is pumped in
The peroxide dissolves the uranium, and the solution is pumped back up
An ion exchange system causes the uranium to precipitate in the form of UO42H2O (uranium peroxide)
In Situ Leaching
ISL has its woesGround water supply has radioactive residues
There are ISL mines in Texas, Wyoming, and Nebraska that share the same aquifers as residents
Nucleons more tightly bound in Fission Product Nuclei Gives 200 Mev Energy per Fission
Three Mile Isle
Nuclear Plant FutureThe countries of the world are each planning their own course of nuclear plant development or declineNuclear power is competitive with natural gas It is non-pollutingIt does not contribute to global warmingObtaining the fuel only takes 5% of the energy outputPlant licenses have been extended from 20 years to an additional 20 years
Nuclear Plant FutureNewer designs are being sought to make them more economical and saferPreapproval of a few designs will hasten developmentDisposal of high level radioactive waste still being studied, but scientists believe deep burial would workBecause they are have large electrical output, their cost at $2 billion is hard to obtain and guarantee with banksReplacing plants may be cheaper using the same sites and containment vessels
Nuclear power generation does emit relatively low amounts of carbon dioxide (CO2). The emissions of green house gases and therefore the contribution of nuclear power plants to global warming is therefore relatively little.This technology is readily available, it does not have to be developed first.It is possible to generate a high amount of electrical energy in one single plant
DISADVANTAGESThe problem of radioactive waste is still an unsolved one.High risks: It is technically impossible to build a plant with 100% security.The energy source for nuclear energy is Uranium. Uranium is a scarce resource, its supply is estimated to last only for the next 30 to 60 years depending on the actual demand.