Energy

What is Nuclear Energy?

What is Nuclear Energy?

Nuclear energy - When energy from controlled nuclear fission is used to create electricity.

What is the process?U235 is bombarded with neutrons in the core of a nuclear reactor. The neutrons cause the nucleus of the uranium atom to split into 2 smaller substances.More neutrons, and a tremendous amount of energy are released.

What is Nuclear Energy?

The release of the neutrons causes a chain reaction.

To prevent the reaction from getting out of control, control rods made of boron and cadmium absorb some of the neutrons, slowing the reaction.

What is Nuclear Energy?

The thermal energy released by the nuclear reaction superheats water in the core.

The water is pumped through a heat exchanger, causing water in another tank to boil and produce steam.

This steam turns the blades of a turbine attached to a electrical generator, producing electricity.

Inside a Nuclear Reactor

What About Nuclear Waste?

Once the fuel rods in the reactor have finished reacting, they are still highly radioactive and must be carefully stored until radioactivity levels are within acceptable limits. For U235 the half life is 700 million years!

The nuclear waste products (the new substances formed in the reaction) have varying half lives.

What about Nuclear Waste? In 1987 Congress chose a site under Yucca Mountain, a

barren volcanic mountain in Nevada, as the prime

candidate for the storage of nuclear waste. After

considerable scientific and political controversy, the

Energy Department decided (in Jan. 2002) to

recommend this as the site for storage of waste from

both military and civilian reactors. The

recommendation remained controversial, and in 2009

President Obama announced his opposition to the

Yucca Mountain site, saying "we can do a better job."

At present a Blue Ribbon Commission is re-evaluating

the problem, and is to present a report in 2011.