nuclear energy at a crossroads. benefits reactors generate electricity without adding to global...

Nuclear energy at a crossroads

Benefits

• Reactors generate electricity without adding to global warming/air pollution.

• Small amt. of U gives off large amts. of energy

• 150 lbs. of U 235 = 30 000 000lbs TNT

• U.S. has more energy in known U reserves than coal or gas.

Pool type breeder reactor

Problems

• Reactors and nuclear missiles create radioactive waste with very long half-lives

• Plutonium is highly toxic

• Waste must be stored safely for at least 20 000 years

Canister burial deep underground

Low level waste

• Source: medical procedures, research, cleanup materials.

• 10 years in storage = 100 X less radiation

• May be removed later to landfills.

Maxey Flats storage facility, KY

High level waste

• From N power plants and N missiles

• Material takes

720 000+years to decay

• Best option: deep burial underground

• Prevents escape into air or ground water.

Yucca mountain, NV

Disposal options

Why not………..

• Bury it under the ocean floor?

too expensive

• Blast it into space?

too expensive, could leak into atmosphere, could explode on takeoff

• Recycle it?

already being done

Transmutation/ recycling N fuel

• Changes high level waste to elements w/shorter ½ lives

• Breeder reactor: spent fuel is reprocessed to convert Pu to U for reuse

• Hybrid reactor: uses neutrons to convert U to smaller, less toxic elements (experimental)

Fast breeder reactor, Japan

The H bomb

• Exploded 1952 on Eniwetok island, S. Pacific• 9+ countries now have nuclear weapons.

Nuclear proliferation

• N power plants/ U refineries create Plutonium that can be used to make N bombs.

• When a country builds a N power plant, it causes international concern.

• Are they using it for electricity, or for war?

Fast breederreactor

US Peacekeeper nuclear missile

1954 H bomb

Humans have unlocked the power inside an atomWhat we do with that power is a question we must all ask and answer for ourselves.

‘Bravo’ Hydrogen bomb crater, 1956 Bikini atoll