Reactor Pressure Setpoints/Actuations and Bases Flashcards
What happens at an RPV pressure of 60 psig?
RCIC system isolates
What happens at an RPV pressure of 135 psig?
RHR Shutdown Cooling isolates
What is the significance of an RPV pressure of 785 psig?
Tech Spec safety limit: With the reactor steam dome pressure < 785 psig or core
flow < 10% rated core flow: THERMAL POWER shall be < 23.8% RTP.
With the reactor steam dome pressure > 785 psig and core
flow > 10% rated core flow: The Minimum Critical Power Ratio (MCPR) shall be > 1.10
for two recirculation loop operation or > 1.11 for single recirculation loop operation.
What happens at an RPV pressure of 807 psig?
MSIV isolation
What happens at an RPV pressure of 926 psig?
Low-Low Set SRV B21-F051D closes
What happens at an RPV pressure of 936 psig?
Low-Low Set SRV B21-F051C closes
What happens at an RPV pressure of 946 psig?
Low-Low Set SRV B21-F051G and 3 other Low-Low set SRVs close
What is the significance of 1025 psig?
Normal operating pressure at 100% power
What happens at an RPV pressure of 1033 psig?
Low-Low Set SRV B21-F051D opens
What happens at an RPV pressure of 1040 psig?
High pressure alarm
What is the significance of 1045 psig?
Tech Spec 3.4.12, Reactor Steam Dome Pressure, shall be < 1045 psig. Restore within 15 minutes.
What happens at an RPV pressure of 1065 psig?
Reactor Scram
What happens at an RPV pressure of 1073 psig?
Low-Low Set SRV B21-F051C opens
What happens at an RPV pressure of 1083 psig?
) Reactor Recirc Pumps downshift to slow speed. Reactor Recirc Pumps will trip off if 25 seconds elapse and APRMs are not downscale. 2) ARI initiates 3) Feedwater runback if 25 seconds elapse and APRMs are not downscale.
What happens at an RPV pressure of 1103 psig?
Low-Low Set SRV B21-F051D opens to initiate the Low-Low Set logic
What happens at an RPV pressure of 1113 psig?
9 SRVs open in relief mode, 4 of which are Low-Low Set
What happens at an RPV pressure of 1123 psig?
9 SRVs open in the relief mode
What happens at an RPV pressure of 1165 psig?
8 SRVs open in the safety mode
What happens at an RPV pressure of 1180 psig?
6 SRVs open in the safety mode
What happens at an RPV pressure of 1190 psig?
5 SRVs open in the safety mode
What is the significance of 1250 psig?
RPV design pressure
What is the significance of 1325 psig?
RPV Steam Dome pressure safety limit per Tech Spec 2.1.2
What is the significance of 1375 psig?
Peak pressure at the bottom of the Reactor Coolant System based on 1325 psig in the Steam Dome
What is the basis for the RHR Shutdown Cooling isolation at 135 psig?
Prevent RHR Pump seal damage (135 psig corresponds to a saturation temperature of 365F)
When is the MSIV isolation at 807 psig active?
With the Mode Switch in RUN
What is the basis for the Reactor Scram at 1065 psig?
Prevent exceeding the ASME max design pressure
How do 1325 psig in the steam dome and 1375 at the lowest level in the Reactor Coolant System relate to each other?
The Reactor Coolant System design pressure is 1250 psig. ASME code allows for a maximum pressure transient of 110% which is equal to 1375 psig. 1375 psig at the lowest point in the Reactor Coolant System is equivalent to 1325 psig in the Steam Dome.
What is the most limiting component in the Reactor Coolant System in regards to pressure?
Reactor Recirc suction piping is rated for 1250 psig
