6.6 Nuclear Energy Flashcards
What is Nuclear Fission
A neutron is fired into the nucleus of a radioactive (unstable) element, such as Uranium. Nucleus breaks apart and releases lots of energy (heat) + more neutrons that break more nuclei apart, releasing more energy (chain reaction)
What does Radioactivity refer to
Radioactivity refers to the energy given off by the nucleus of a radioactive isotope (Uranium-235)
Difference between Radioactive nuclei decay and nuclear fission
Radioactive nuclei decay, or breakdown and give off energy (radiation) even without fission; nuclear fission just releases tons of energy all at once
What is Radioactive Half-Life
Radioactive Half-Life = the amount of time it takes for 50% of a radioactive substance to decay (breakdown)
Ex: ½ life of Cobalt-60 isotope = 5.27 yrs.
In 5.27 yrs, ½ of a Co-60 sample would be
Gone (decayed)
Same electricity generation process as with FFs, just uranium fission to heat water into steam
Heat →Water into Steam → Steam turns a turbine → Turbine powers generator → Generator produces electricity
What are Control Rods in a Nuclear Power Plant
are lowered into reactor core to absorb neutrons and slow down the reaction, preventing meltdown (explosion)
What are Water Pumps for in a Nuclear Power Plant
brings in cool water to be turned into steam and also cools reactor down from overheating
What is the Cooling tower for in a Nuclear Power Plant
allows steam from turbine to condense back into liquid and cool down before being reused (this gives off H2O vapor)
Why is Nuclear Energy NONRENEWABLE
No air pollutants (PM, SOx/NOx) or CO2/CH4 released when electricity is generated; mining of uranium & plant construction still release GHGs
Only gas released from elec. gen. is water vapor (which is technically a GHG, but stays in atm, very briefly)
Spent Fuel Rods:
used fuel rods remain radioactive for millions of years & need to be stored in lead containers on site @ Nuclear PP
Mine tailings:
leftover rock & soil from mining may have radioactive elements that can contaminate water or soil nearby
Water Use:
nuclear PPs require lots of water and can deplete local surface or groundwater sources
Thermal Pollution:
hot water from PP released back into surface waters can cause thermal shock (decreased O2 & suffocation)
Nuclear Meltdown Impacts:
Contaminated soil: radiation can remain in soil and harm plants and animals in the future (genetic mutations)
Radiation spread: radiation can be carried by the wind over long distances, affecting ecosystems far from the meltdown site
What happened in the Three Mile Island
partial meltdown due to testing error; radiation released but no deaths or residual cancer cases
