Energy #3: Nuclear A

Energy #3: Nuclear A

Multiple Choice

Nuclear energy plants in the USA currently total ______ which are still "on-line" or active. A plant that is no longer able to produce electricity is said to be 'de-commisioned'

• 56

• 96

• 122

• 1230

There are currently (as of Oct. 2020) 56 commercially operating nuclear power plants in the USA. Most of those power plants contain 2 reactors.

There are 94 nuclear reactors---but many do not produce electricity for public consumption.

Multiple Select

The current type of nuclear power used to produce electricity require:

• a fissionable isotope

• a source of neutrons

• a controlled system

• a high density, high temperature environment

• water for cooling

Nuclear fission- the 'splitting of an atomic nucleus'

• a heavy, fissionable isotope, is needed (enough to support the reaction= "critical mass")

• the isotope must be in a controlled environment of high temperature and pressure

• to initiate the nuclear reaction, the isotope is bombarded with neutrons....which make the isotope even more unstable

• The isotope will split into lighter, less massive 'daughter' isotopes and in the process release energy in the form of heat and radiation

• Nuclear fission doesn't typically occur in nature, except as nuclear decay on a small scale

Multiple Choice

Which is true about the U-235 isotope most commonly used in nuclear fission power plants?

• the U-235 must be more concentrated than what occurs in nature

• 13-15% concentration of U-235 is embedded in pellets used within the reactors

• Uranium 238 ore is condensed into pellets

• Plutonium is the most common fissionable ingredient in pellets of a power plant

Multiple Choice

Which is NOT true about nuclear fission reactions?

• they are common in stars

• they require a critical mass of fissionable material

• they result in lighter nuclei

• they release a million times more energy that what is found in typical chemical reactions

Multiple Choice

The containment vessel houses the control rods (radioactive material) and the pressurized water

• true

• false

Multiple Choice

The heated steam next enters a _____________ which produces electricity and is then sent to transmission lines

• turbine

• condenser

• water tower

• steam generator

Nuclear Power Plants

The walls of the containment vessel are 6 ft thick (cement) . The emissions of water vapor into the atmosphere are non-radioactive. Notice that there must be an intake of water from a lake or river to experience "HEAT TRANSFER"

Multiple Select

Which are some of the "pros" to Nuclear Power Plants?

• No greenhouse gases produced

• a small amount of radioactive fuel can generate a lot of energy

• The plants can work efficiently for up to 40 years

• the control rods are easily stored

• nuclear meltdown events are easily managed

Poll

How do you feel about Nuclear Power Plants?

• I feel they are needed and safe enough

• I feel they are too risky and have more con's than pros

• Before we add more we have to solve the issue with storage of spent fuel

• we need more low cost electricity and so they are necessary

Spent Nuclear Fission Fuel

Used nuclear fuel can be recycled to make new fuel and byproducts. More than 90% of its potential energy still remains in the fuel, even after five years of operation in a reactor. The United States does not currently recycle used nuclear fuel but foreign countries, such as France, do

Spent Nuclear Fuel- ON SITE storage

• Wet Storage

• Dry Storage

Multiple Choice

For ______ years, spent nuclear fuel must be kept in containers of water, in "wet storage"

• 5

• 25

• 10,000

• 1.4 million

Spent Nuclear Fuel Repositories in the USA

• There is currently NO centralized, protected storage site for nuclear waste.

• There are currently 80 sites with stored, spent nuclear fuel in the USA

The Future of Nuclear Fission Power Plants

Following France's lead, there are changes to how spent fuel can be re-processed and used, which would ultimately reduce the amount of U-235 needed and therefore the amount of ultimate waste disposal.

Nuclear Radiation

• Is Natural and Everywhere: In Soil, Plants, Earth and in you

• However, we need to be careful with radiation from power plants to not increase our exposure

• The average US Radiation dose is 620 mrem

• Radiation is measured in millirems (mrem) and milliSieverts (mSv).

Radon Risk

• The average Radon dose in our area is 4-6

• Prolonged Radon exposure above 4 can cause cancer (esp. lung)

• Radon is heavy, odorless and accumulates in basements

• Radon removal systems are an easy solution