General Flashcards
What cladding is used in AGRs (Advanced gas cooled reactor)
Stainless steel
What gas is used as the coolant is AGRs
Carbon dioxide
What is the order of temperature magnitude for the coolant, fuel and cladding along a cooling channel
Fuel > Cladding > coolant
Equation for total power generated in cooling channel
P = mdot c (Tco - Tci)
co coolant out
ci coolant in
Form of non dimensional temperature equation in terms of Tci Tco and T
θ = 2 ((T - Tci)/(Tco- Tci)) - 1
Coolant temperature at mid channel equation
Tc1/2 = 1/2(Tci + Tco)
For what shape does the minimum volume bare core occur
Spherical
Flux equation for spherical geometry
Flux = A/r sin Br
Assumptions used in the reactor kinetics equations (for the lumped models of the behaviour of a source free reactor)
No spatial variation in behaviour
In real life the reactor core is highly heterogenous
Only one type of precursor
In real life there are a large number of them with varying production rates and half lives
Any potted in in hour equation graph
P = -λ
ρ = Λp + β
What does the prompt jump approximation assume
That the neutron population remains in equilibrium with the precursor population
Why is restart impossible impossible for a period after shutdown
As the Xe population will rise, peak then fall. For a period it will be sufficiently high that peak activity loss to axe poisoning will be greater than the excess reactivity available (from the control rods)
Fuel utilisation equation for M batch cycle
B = MTm where Tm = steady state batch time
What ICRP stands for
International commission on Radiological Protection
3 criteria laid down by ICRP
Don’t adopt practice unless risks are outweighed by the benefits
Exposures kept as low as reasonably achievable
Dose equivalents to individuals can’t exceed certain values
Methods of protection against external radiation (3)
Time, distance, shielding
Purpose of dose limits
To prevent: short term effects (burns), long term effects (cancers) and genetic effects.
What is the dose limit for registered radiation workers
20 mSv/yr
Assumptions on which dose limits are based
No threshold dose exists and any dose involves a proportionate risk of cancer
Doses received on separate occasions act cumulatively
Equation for the shield flux (flux at the edge of shielding)
φ’ = φ e^[-αd)
Φ unshielded flux
α attenuation coefficient
d distance
Equation that helps you find the criticality condition
α^2 + β^2 = Bm^2
Alpha and beta found by solving each variable in the differential equation.
How to derive the in hour equation
Take Laplace transforms (variable p) of both the reactor kinetics equations, substitute for co and substitute for c bar to get a an equation just in n
Then to take inverse transforms need to reduce to partial fraction form, which means setting denominator to zero, then equation pops out with density on one side.
