Nuclear Energy Flashcards
When was nuclear fission discovered and by whom?
in 1939 by Lise Meitner and Otto Frisch
What is the most common type of nuclear fission?
Uranium-235
Is uranium-238 fissionable?
no
What are the products of a uranium-235 fission reaction?
Barium-144 (not always), Krypton-89, a few neutrons, around 200 MeV, and gamma rays
What causes a fission reaction?
a slow-moving neutron (its impact)
Can fast neutrons be captured by a uranium nucleus?
No
A single fission event can yield over ____________ times the energy of the neutron which triggered it
200 million times
If a fission reaction will sustain itself, it is said to be __________
critical
What is critical mass?
the mass of U-235 required to produce the critical condition
A fission chain reaction produces what?
intermediate mass fragments that are highly radioactive
What’s another name for fusion reactions?
Thermonuclear reactions
Fusion reactions only take place when the nuclei have large amounts of ________
thermal (kinetic) energy
What amount of energy is released by the fusion of one helium nucleus?
25 MeV
The fusion of deuterium and tritium requires a temperature of approximately __________
40 million Kelvins
What produces more energy per mass, fission or fusion?
Fusion
What country produces most of the enriched uranium for the nuclear reactors in the western world?
USA
How many nuclear reactors are there worldwide?
443
Where has there been nuclear reactor “disasters” (3)?
Three mile island, chernobyl, Japan
What are two types of light water reactors?
Pressurized water reactor (PWR) and boiling water reactor (BWR)
T or F: In light water reactors, it is necessary to enrich the uranium fuel
True
Pressurized water reactors contain how many tonnes of uranium fuel?
200 tonnes
How many loops do pressurized reactors have?
two
What is placed between uranium rods, in PWRs?
cadmium rods (control rods)
What is able to spin the turbines in PWRs?
pressurized steam
