Practise balancing fission equations, calculating energy from mass or binding-energy changes and analysing neutron multiplication, criticality, control and reactor energy transfer.
This question is in two parts. Part 1 is about energy resources. Part 2 is about thermal physics.
Part 1 Energy resources
Electricity can be generated using nuclear fission, by burning fossil fuels or using pump storage hydroelectric schemes.
In a nuclear reactor, outline the purpose of the
heat exchanger.
(allows coolant to) transfer thermal/heat (energy) from the reactor/(nuclear) reaction to the water/steam;
Must see reference to transfer.
moderator.
reduces speed/kinetic energy of neutrons; (do not allow "particles") improves likelihood of fission occurring/U-235 capturing neutrons;
Fission of one uranium-235 nucleus releases 203 MeV .
Determine the maximum amount of energy, in joule, released by 1.0 g of uranium-235 as a result of fission.
( 203 MeV is equivalent to) 3.25×10−11 J;
6.02×1023 nuclei have a mass of 235 g/ evaluates number of nuclei;
( 2.56×1021 nuclei produce) 8.32×1010 J/ multiplies two previous answers;
This question is about nuclear power production.
Outline the reason why fuel enrichment is necessary for the fuel used in a commercial nuclear reactor.
U-235 is (much) more fissionable that U-238 / U-238 is a good absorber of neutrons / U-238 removes neutrons from the reaction / U-238 cannot produce a chain/sustainable reaction;
(naturally occurring) uranium (ore) contains more U-238 (atoms) than U-235 (atoms) / very little U-235 in ore;
in fuel enrichment, U-238 is removed / the percentage of U-235 is increased / the ratio of U-235 to U-238 is increased / amount of U-235 increases;
This question is about energy sources.
A small island is situated in the Arctic. The islanders require an electricity supply but have no fossil fuels on the island. It is suggested that wind generators should be used in combination with power stations using either oil or nuclear fuel.
A nuclear reactor requires both control rods and a moderator to operate. Outline, with reference to neutrons, one similarity and two differences in the function of each of these components.
control rods absorb neutrons;
moderators slow down neutrons;
both affect the rate of reaction;
both rely on the neutrons colliding with their atoms/nuclei;
Must see reference to collision/interaction for fourth marking point.
5. Part 1 Thermistor circuit