2022 MCQ Flashcards
What is the KE of a fission neutron?
2 MeV
What is the KE of a thermal neutron?
0.023 eV
What is the energy release on U235 fission?
200 MeV
What is the energy of burning an carbon atom?
20 eV
What is the energy required to displace an atom in a metal lattice?
20 eV
What does probabilistic safety analyse?
How likely different accident sequences are.
Following a loss of coolant accident, a typical PWR fuel element will reach the fuel melting point (in the absence of any cooling) after typically
500 seconds
What does deterministic safety analysis address?
Consequences of accident sequences
What might be used as the coolant and the moderator in a plutonium-breeding reactor?
Sodium, no moderator at all
What reactor type is considered best suited to support the production of hydrogen?
HTGR (High temperature gas cooled reactor)
What is not a claimed feature of SMR?
Thermal efficiency
Which of the following is the least significant factor in the economic assessment of nuclear power:
Electricity Price
Thermal Efficiency
Discount Rate
Decommissioning costs
Decommissioning costs
What is the I-131 equivalence of Cs-137?
1TBq of Cs-137 = 40 TBq of I-131
How does the atomic mass vary when it undergoes fission?
Increases by one (neutron captured)
How to calculate neutron number density of core containing mixture?
Calculate individual neutron number density then multiply by volume ratio (make use of RVE)
What is k_infinity calculation?
SUM: v(i)n(i)sigma_f(i)
DIVIDED BY
SUM: n(i)*sigma_a(i)
Does K_infinity inform criticality status?
No
What value informs the criticality status?
multiplication factor (k)
How can the multiplication factor (k) be calculated from k_infinity?
six sigma formulation
k_infinityP_FNLP_TNL
What is the most important of the following factors that influences the difference between coolant temperature and clad temperature in a typical PWR in normal operation?
coolant density
What is a subchannel?
Channel between pins
Nuclear cogeneration systems for district heating schemes use
Waste water/steam from the turbine exit
The fuels in a ‘commercially viable DT fusion reactor comprise of:
Deuterium and Lithium
A prototype fusion reactor is able to maintain an ion density of 6E+20 ions/m3, at a temperature of 150E+6 K for 0.01 seconds. Which one of the following statements is true?
Would fail to reach ignition
What material does not exhibit swelling?
Ceramic MgAl2O4
In a supercritical water-cooled reactor, the coolant is
light water at 230 bar
What is the equation for intensity?
I = I_0 * exp(-urhox)
True or false: Delayed neutrons are relatively rare, but extend the average neutron lifetime enough to make the reaction controllable.
True
A U238 nucleus undergoes neutron capture, followed by beta-decay, and then a subsequent additional beta decay. The resulting nucleus is
Pu239
If the control rods of a nuclear fission reactor are fully inserted, the nuclear chain reaction will, in normal circumstances,
shutdown
What nuclear reactor type does not use a steam generator?
BWR
In a PWR in which a large break loss of coolant accident occurs,
the core depressurizes and the liquid water flashes to steam which exits through the break
Which of the following would not be good for providing shielding from neutrons and why?
Boron
Gadolinium
Beryllium
Carbon
Beryllium, smallest atomic mass
How long does fuel remain in a PWR core?
5 years
What is an advantage of natural circulation?
Reduced cost
Does not rely on power source
List the following in order of decreasing fissile number density:
Natural uranium metal
U238 metal
Pu239 metal
UO2 made from natural uranium
UO2 made from pure U235
Pu239 metal
UO2 made from pure U235
Natural uranium metal
UO2 made from natural uranium
U238 metal
List the following in ascending order of core coolant exit temperature:
AGR
Gas cooled fast reactor
PWR
PWR
AGR
Gas cooled fast reactor
