Nuclear Power

Dylan WaybrightKendall CaminitiGina RaimondoSusan Ellington

Paige Urbanovsky

Our topic is covering the discussion of Nuclear Power. It is the world’s biggest source of emission-free energy. Nuclear power plants produce no controlled air pollutants, like sulfur and particles, or greenhouse gases.

Around 20% of electricity generated in the U.S comes from Nuclear power. In the last 40 years, not one single fatal accident has came up, but on the other hand, many people die in coal mining accidents, such as 10,000 Americans dieing every year from pollution relating back to coal. Gina R.

American Nuclear Power Plant

A coolant transfers heat from the reactor core to a steam

generator, where the heat turns water into steam. The steam drives turbines that produce

electricity before being pumped back to the reactor.

Paige U.

Concept of Fission

• The fission process results in the release of large amounts of energy.

• An element must have a reasonably long half life.

• Last, an element must be available in suitable quantities.

Dylan W.

Chain Reaction

• A chain reaction occurs when a fission reaction takes place producing neutrons which then act in creating a new fission reaction. This process will continue and make the amount of fission in a block material grow rapidly.

• The average fission reaction produces 2.3 neutrons.

Dylan W.

Critical Mass

• Critical mass is the smallest amount of fissile material needed to sustain a nuclear chain reaction.

Dylan W.

Elements Capable of Undergoing the Process of

Fission• Elements that are commonly used in

reactors are Uranium-235, Uranium-233, and Uranium-233.

• Other elements that have never been used to make energy but are known to fissile are Plutonium-239, Neptunium-237, Curium-244, Americium-24.

• All elements on the periodic table above 83 are known to be capable of fission.

Dylan W.

What Makes an Element Capable of Fission?

• An element must be in the region of the binding energy curve where a fission chain reaction is possible (i.e. above Radium)

• An element must have a high probability of fission on neutron capture.

• An element must release two or more neutrons on average on fission.

Dylan W.

Nuclear Submarines

A controlled nuclear reaction generates the heat which turns water

into the steam that drives the submarines engine.

Paige U.

http://10.200.10.53/videos/11876/chp898115_700k.asf

Paige U.

Breeder Reactors

Fast breeder reactors use fast neutrons produced by fission without slowing

them down as in the thermal reactor.

Paige U.

Controversies surrounding nuclear power

• Nuclear power is considered cleaner than coal.

• Mining Uranium is not clean.• Transportation is risky.• The accident in Chernobyl resulted in

fatality.• Radioactive waste is generated during the

production of electricity by nuclear power plants.

• Possibility for weapon production by a terrorist group is at risk.

Susan E.

Advantages of Nuclear Power

• Nuclear Power is better for the environment.

• High electricity can be made from a little amount of fuel.

• Small amount of waste.

Kendall C.

Disadvantages of Nuclear Power

• Nuclear waste is very dangerous.• High risk in using nuclear power.• Energy for Nuclear power comes

from Uranium which is a scarce element

• It takes a lot of time to build a nuclear power plant.

Kendall C.

Positive and Negative

http://10.200.10.53/videos/643/chp1711_700k.asf

Kendall C.

What happened at Chernobyl and Three Mile

Island?Chernobyl:• At exactly 1:21 am on April 26, 1986 in

Chernobyl, the No. 4 reactor exploded.• Operators circumvented safety systems to

conduct a test. • A steam explosion at lifted the 1000-ton

upper reactor cover, allowing all the water in the core to escape.

• A second explosion occurred and burning graphite and hot core material started about 30 fires.

Susan E.

Three Mile Island:• Accident took place at reactor TMI-2.• At 4 AM March 28, 1979 a minor

malfunction occurred shutting down water pumps in the secondary loop.

• Backed up water pressurized in the primary loop and the temperature increased.

• PORV released pressurized steam into the holding tank.

Susan E.

What Caused the Accidents?

Three Mile Island:• PORV should have closed off after steam

built up • Warning light never turned on.• Backup safety mechanisms were activated.• Operator opened up valves. • Tons of steam and hot water accumulated

in PORV.

Susan E.

Three Mile Island:

• Operator noticed temp. of steam 2 ½ hours later and shut off the PORV backup valve.

• Radioactivity in primary loop was 350 times the normal level and alarms went off.

• Radioactive gases leaked and the system exploded, increasing temperature and pressure.

• 15 hours later the situation was put under control.

Susan E.

Aftermath of these catastrophesEffects of Three Mile Island:• 250,000 gallons of highly radioactive water

were released from the pressure relief valve system.

• Pennsylvania had serious health & environmental risks.

• Half of the power plants core melted and the core partially disintegrated.

• Changes in government, nuclear power plan for emergencies, trained operators, and disposal of radioactive materials.

• Little has been done for safer fuel alternatives, such as solar energy.

Susan E.

Effects of Chernobyl:• 240 people were hospitalized after the first day• Air flow in the damaged reactor building fed a

fire in the graphite in the core. • About 12 megacuries of radioactivity were

released on the first day. • Temperatures and emissions increased after

April 31. • The fire was extinguished on May 6 after about

52 megacuries had been released by the fire.• 31 fatalities and 209 were treated for poisoning.

Susan E.

Why water and where does it end up?

• Water is used as a moderator and a coolant in nuclear power plants.

• The large amount of water that is taken from rivers, streams or lakes harms the aquatic life.

• When the water goes back into the rivers it also hurts the aquatic life.

Kendall C.

Summing up the main ideas of nuclear power, we now understand that it is the world’s biggest source of energy. As for equipment involved with nuclear power, the heat in a steam generator turns the water into steam, also Nuclear generators allow nuclear submarines to drive longer, faster, and deeper. In the chemistry outlook, the fission process results in the release of large amounts of energy, and critical mass is the smallest amount of fissile material needed to sustain a nuclear chain reaction. Looking back at the history of nuclear power, the major catastrophes were Three Mile Island and Chernobyl that had major effects afterwards. At Chernobyl, the No. 4 reactor exploded and at Three Mile Island, a minor malfunction occurred. Last, the water in the Nuclear Power plants used as the moderator and the coolant. I am sure you found out a lot of things you did not know about Nuclear Power and Nuclear Power Plants.

Gina R.