Miscellaneous Flashcards
Fuel costs thumbrule
$100k per 0.01 w/o
Enrichment change vs burnup thumbrule
0.1 per GWD
Reactor power equations
Q=UA*(Tcen - Tbulk)
Q=mcP*dT
SG power equations
Q=UA*(RCS Tavg - Tsteam)
Q=m*(hsteam - hfeed)
Average lifetime of prompt and delayed
Prompt: 2e-5 s
Delayed: 13 s
Beta, Beta-bar, Beff
Beta: fraction of delayed n of given isotope
B-bar: weighted avg of isotopes weighted by fraction of fissions of that isotope
B-eff: I * B-bar
Power vs time using SUR or period
P = Po * 10^(SUR * t) P = Po * e^(t/period)
Equation relating SUR and period
SUR = 26.06 / period
Why is it best to set the gamma comp voltage shortly after shutdown?
Delayed neutron Groups 2-6 decay away after ~20 min.
The half life of Group 1 results in a period of -80 s.
SUR = 26.1 / period = -0.3 DPM
i.e. the neutron flux is decreasing at -0.3 DPM
SUR equation using point kinetics
SUR = 26.06 * lambda * rho / (Beff - rho)
How long for EQXE after a change in power?
Increase / decrease: 50 hours
Trip: 70 hours
When does xenon reach peak / valley after change in power?
Increase: 3 hours to valley
Decrease: 6 hours to peak
Trip: 9 hours to peak
3, 6, 9 up, down, shutdown
What are the design bases for the PZR and SD systems? (with rods in auto)
Allow the following without a trip:
- Load change at +/-5% / minute
- Step change of +/-10%
- Step load rejection of 50% (40% SD, 10% rods)
Define reactivity
The fractional departure of Keff from criticality
SDM definition
Instantaneous amount by which the reactor is or will be subcritical at N-1 and 557
