Exam 3-Chapter 15 Flashcards
high and low doses of radiation (what they do)
high-prevent cell division/radiation sickness/prevents the replacement or repair of blood, skin, or other tissues. can cause death immediately or in days or mos. Low doses can damage DNA, cells can form malignant tumors or leukemia/damaged eggs or sperm=birth defects/effects can go unseen 10 to 40 yrs/weakened ammune system, mental retardation, cataracts.
nuclear reactors usually fission or fusion and why
fission because is uses less energy and uranium is naturally occurring in earth’s crust
what is the difference between nuclear fission and fusion
fission uses less energy/a large atom of one element is split into two atoms of different elements. Fusion uses more energy/two small atoms join to form a larger atom of a different element.
compare/contract nuclear and coal power plants
Both 1000 MW-coal emits 7 mil tons of CO2, 300,000 tons SO2, 100 times more radioactivity released than nuclear, accidents can kill people or lead to fires. Nuclear has no CO2/no acid forming pollutants/low levels of radioactive waste gas/BUT 250 tons highly radioactive wastes require storage and disposal. Accidents can range form minor to catastrophic.
why is coolant so important in reactor
LOCA-loss-of-coolant accident. loss of this water would stop fission, then fuel core overheating. that’s why they have backup coolants.
why is there opposition to nuclear power
distrust of technology that has potentially catastrophic accidents and can cause cancer. arguments of extreme safety fall apart when accidents occur/problems with waste disposal/plants targets fro terrorism/high construction costs
is nuclear energy renewable
it is not renewable
difference/fuel rods and control rods (about)
fuel rods contain uranium dioxide pellets loaded into long metal tubes and placed close together to form a reactor core. Control rods are inserted between fuel elements. they are neutron absorbing material. they control the chain reaction in the reactor core (inserting and removing these rods starts and controls the chain reactions.
what is nuclear energy
the objective is to control nuclear reactions so that energy is released gradually as heat. heat energy produced by nuclear plant used to boil water and produce steam which drives turbogenerators
elements used for fission and fusion
fission-uranium 235. fusion hydrogen-2 and -3, and helium
what is half-lives
amount of time for half of the radioactive isotope to decay. uranium 235 700 million yrs for half to decay (uranium 238 half life is 4.5 billion years)
where does nuclear energy come from
by fission (splitting uranium-235) in reactor core
benefits and drawbacks of nuclear power
clean energy source. There are risks of plant meltdowns where radiation exposure occurs. A lot of safety precautions have to be put in place, but never for sure.
how do we generate electricity from nuclear power
fission occurs in reactor core where fuel rods are submerged in water. Water slows neutrons and causes a chain reaction in uranium-235. control rods regulate the reactions. water heated by fission in primary loop but doesn’t boil because it’s pressurized. heated water in secondary loop is boiled causing steam, the steam drives turbines and generates electricity
