GFES Flashcards
Why do we adjust the synchroscope for rotation slowly in the fast direction with incoming voltage slightly higher than running voltage?
Higher Frequency and a slightly higher voltage ensures the generator will pick up the load
What is the equation for Calculated Thermal Power?
CTP = Qsteam + Qblowdown + Qambient + Qletdown
- Qmakeup - Qfeedwater - Qrcp - Qpzr
What is Differential Rod Worth?
The change in REACTIVITY PER UNIT change in rod position
Slope of the IRW curve
What is Integral Rod Worth?
The change in REACTIVITY PER TOTAL change in rod position
Sum of DRWs between initial and final rod positions
Point to point
What adds the most positive reactivity following a Rx Trip?
FTC - bc of drastic change in fuel temp
What is a prompt neutron?
A neutron w a life of 10E-14 seconds or less
What is a delayed neutron?
A neutron life of ? 10E-14 secs
Avg 12.5 seconds
Which type of neutrons are Rx Power decreases more limited by?
Delayed neutrons
What are the pump laws?
Flow Rate : Pump Speed
Discharge Head: Pump Speed ^2
Pump Power: Pump Speed ^3
1 in HG is = to how many psi?
0.491 psi = 1”Hg
1 ft of water = how many psi?
0.433 psi = 1 ft H20
What are the indications of a dead headed pump?
Lower Flow
Low Amps
Pump will over heat
What are the indications of Pump Run Out?
High flow
High amps
What are the indications of Cavitation?
Low Flow
Amps Fluctuate
Pressure Fluctuates
1 psi = how many feet of water?
1 psi = 2.3 feet of water
What kind of stress is the result of a heatup?
Compressive stress due to inner wall heating up faster than the outer wall
What kind of stress is felt during a Cooldown?
Tensile Stress due to the inner wall cooling down quicker than the outer wall
Once the PRT pressure rises to the point that the rupture disc ruptures, what happens to PRZ PORV Outlet Temperature?
Lowers from the saturation temp for 100 psig to the saturation temperature for containment pressure
At the EOL, what type of reactivity do MTC and FTC add?
Both add negative reactivity at EOL
Explain how a lowering temperature in containment affects indicated PRZ Level.
PRZ Level has a wet ref leg DP indicator.
As temp in containment (ref leg) lowers, it becomes more dense, and weighs more. This means the level in the pressurizer indicates lower for the same initial value
Explain how indicated PRZ Level is affected if containment temperature rises. Assume RCS Pressure and Temp remain constant, and that actual level does not change in the PRZ.
Density lowering in the reference leg causes indicated PRZ Level to read higher than actual level.
With a negative MTC, how will a raise in steam flow affect reactor power?
Rx Power will increase to a new, higher value.
The increase in steam flow lowers RCS temperature which adds positive reactivity due to the negative MTC.
What happens to Differential Rod Worth over core life?
Becomes more negative (worth more) due to a lower boron concentration and a shift in radial flux
Flux shifts to the outer portion of the core, so more rods are exposed to a higher flux
What equation is used to determine break flow for a given pressure?
Break Flow : Square Root of DP
Final flow / initial flow : Square Root of (final pressure / initial pressure)
If power is lowered by emergency boration with no rod movement, what will happen to axial power distribution?
Shifts toward the top of the core, where Xenon production will be less
