NUCLEAR CHEMISTRY

Chapter 21

February 26, 2009

Nuclear Chemistry in Everyday life:

1. Nuclear Power Plants• FPL uses nuclear power to

generate 18% of Florida’s energy needs

• Locations: Turkey Point, St. Lucie, Crystal River

• All located near water for reactor cooling purposes.

TYPES OF ENERGYother than Nuclear• Fossil Fuels (oil, coal, natural gas)

• Solar (sunlight)

• Bioenergy (power from plant material)

• Electric Power (electric power via coal) 50% in USA

• Hydrogen (clean like electricity made from renewable energy like solar, geothermal, wind)

• Hydropower (water power) Hoover Dam

• Geothermal (heat from within Earth)

• Fusion (plasma)

• Wind

Nuclear Energy

20% of all energy generated in America today is nuclear energy

Only method in use today is through nuclear fission, though other methods might one day include nuclear fusion and radioactive decayAll utility-scale reactors heat water to produce STEAM, which is then converted into mechanical work for the purpose of generating electricity or propulsion.

Nuclear Energy

Nuclear Energy

• Nuclear power can come from the fission of uranium, plutonium or thorium or the fusion of hydrogen into helium.

• Today it is almost all uranium. The basic energy fact is that the fission of an atom of uranium produces 10 million times the energy produced by the combustion of an atom of carbon from coal.

• Natural uranium is almost entirely a mixture of two isotopes, U-235 and U-238. U-235 can fission in a reactor, and U-238 can't to a significant extent. Natural uranium is 99.3 percent U-238 and 0.7 percent U-235.

Nuclear Fission (the splitting of atoms creates tons of energy)

The problem with NUCLEAR Power

• The used reactors are radioactive.• If an accident happens, radiation

will travel through the air to surrounding areas.

• Ex: Chernobyl Disaster of 1986

The 1986 Chernobyl Accident Reactor #4 overheated due to a design flaw!

Disaster responsible for 4,000-200,000 deaths• hydrocephalus -abnormal accumulation of cerebrospinal fluid

(CSF) in the ventricles, or cavities, of the brain. • Birth defects caused by radiation from nuclear blasts• Radiation traveled over 300 square miles

YES

• Chernobyl is back in business today with reactors 1, 2 and 3.

• Reactor 4 remains closed

GEIGER COUNTER

GEIGER COUNTER

This is as close as the authorities would allow us to reach reactor number 4 without protective suits. Even so, we were only allowed there for a maximum of 5 minutes as the Geiger counter in my hand shows that 3 times the amount of radiation from a normal chest x-ray was shooting through us!

1986 Chernobyl (Ukraine)

Film Badge- shows how much radiation exposure a person has been exposed to in a nuclear power plant.

Nuclear Chemistry in Everyday life:2. Nuclear Medicine-Radiology-Dyes (radiotracer injected or

swallowed)-CT, MRI, Xray, Chemotherapy-Radioactive Iodine (I-131) treatment-Thyroid issues

Nuclear Medicine imaging are used to:

• analyze kidney function • visualize heart blood flow and function• scan lungs for respiratory and blood flow problems • identify blockage in the gallbladder • evaluate bones for fracture, infection, arthritis and

tumors • determine the presence or spread of cancer • identify bleeding into the bowel • locate the presence of infection • measure thyroid function to detect an overactive

or underactive thyroid • investigate abnormalities in the brain

Nuclear Medicine imagingMRI (magnetic resonance imaging)

Nuclear Chemistry in Everyday life:

3. Smoke DetectorsUse Americium-241 to detect smoke.

(alpha radiation)

Nuclear Chemistry in Everyday life:

4. FOOD IRRADIATIONRadiated foods have a longer shelf

life than normal.Gamma ray radiation preserves

foods. Meats, fruits, veggies.

Food Irradiation

• Are irradiated foods safe to eat?Yes. Just as pasteurization makes milk safer, irradiation makes meat and poultry safer by reducing the numbers of harmful bacteria and parasites. Irradiation is an important food safety tool in fighting foodborne illness.

Food Irradiation

• Are irradiated foods safe to eat?

Until recently, only irradiated dried spices and enzymes were marketed in the United States. In January 1992, irradiated Florida strawberries were sold at a North Miami supermarket. Sales of irradiated products are ongoing in several grocery stores. Poultry irradiation began commercially in 1993.

Irradiation of food has been approved in 37 countries for more than 40 products. The largest marketers of irradiated food are Belgium and France (each country irradiates about 10,000 tons of food per year), and the Netherlands (which irradiates bout 20,000 tons per year).

Food Irradiation

• Are irradiated foods safe to eat?

Food Irradiation

• Symbol on foods that have been irradiated: the RADURA (comes in any color!)

Nuclear Chemistry in Everyday life:

5. Pest-Control IrradiationRadiation vs Pesticides

Gamma radiation sterilizes pests.No reproduction will occur.

DDT-Bald Eagle- 1970’s

Nuclear Chemistry in Everyday life:

6. Archeological DatingHow old are dinosaur bones??How long as a body been

decomposing?Using Carbon-14 dating these

questions can be answered.

Archeological Dating

-Carbon-14 (in living tissue) is compared to the ratio of Carbon-12 (in decomposing tissue) by mass gives an estimated time of death.

-Half-life (t1/2) = when half of a substance has decomposed or radiated.

-Carbon-14 has a t1/2 = 4,700 years

Nuclear Weapons

• 7. USA is the only country to use nuclear weapons on another country.

• EIGHT countries have nuclear weapons• Britain, China, France, India, Pakistan,

Russia, United States, North Korea (Israel??) (Iran is seeking nuclear weapons)

Nuclear Weapons

• Hiroshima and Nagasaki

• USA drops Atomic Bomb on Japan on August 6, 1945

Hiroshima Today

Hiroshima Today

• Not radioactive because bomb burst in air allowing the ground to be virtually radioactively free.

• This is unlike Chernobyl which made non-radioactive material (like the soil) in the ground radioactive…hence taking longer time to dissipate

Hiroshima 1945

Hiroshima TodayPlace MAZDA is manufactured

Hiroshima Today

Alpha, Beta, Gamma

Electromagnetic Spectrum

EM Spectrum

LOW

ENERGY

HIGH

ENERGY

R O Y G. B I V

red orange yellow green blue indigo violet

Sites to View

• Power Plant Timeline• http://

www.animatedsoftware.com/poifu/poifu.swf

• http://www.colorado.edu/physics/2000/bec/temperature.html