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How does using a lower feedwater flow than actual when calibrating COLSS safety channels affect VOPT?
It makes the VOPT less conservative.
When do COLSS safety channels become out of service due to ICIs?
If enough ICIs fail, COLSS is declared out of service.
What does COLSS Power Limit Margin compare?
Smoothed plant power vs the most restrictive of licensed power, DNBR POL, and LPD POL.
What happens in COLSS if Tcold decreases?
Plant power (JCPCAL) increases, then calibration to JSCALOR brings it back to the original value.
What happens to tilt in COLSS if a CEA slips into the core?
Tilt increases because ICIs detect the flux shift.
How does COLSS interpret a CEA drop into the core?
COLSS assumes the entire group dropped.
What happens to the LPD Power Operating Limit if CEAs are inserted into the core?
LPD POL decreases.
What happens to DNBR and LPD POL if pressurizer pressure decreases?
DNBR POL decreases; LPD POL is unaffected.
What happens if feedwater temperature fails low in COLSS calculations?
JSCALOR increases, affecting other calculated powers.
How does a more negative ASI affect the DNBR Power Operating Limit?
DNBR POL decreases.
What inputs are used for the COLSS NKBDELT calculation?
Tcold and Thot.
What is the functional difference between COLSS and CPC?
COLSS provides indications and alarms; CPC provides protection and reactor trips.
What happens if blowdown is secured but constants remain in COLSS calculations?
JCPCAL will initially be lower and will decrease further after about one hour.
What happens to NKBDELT if RCP differential pressure decreases?
NKBDELT increases.
What happens if blowdown is secured but constants remain in the JSCALOR calculation?
The JSCALOR calculation becomes non-conservative.
How are COLSS input failures detected?
Failures are sensed by both the Process Computer (PC) and the Core Monitoring Computer (CMC).
What flow parameter does COLSS use in DNBR calculations?
Volumetric flow rate.
