COLSS: Core Operatng Limit Supervisory System Flashcards
What is the basis for the COLSS DNBR POL?
Assures that the worst AOO wont cause DNBR < 1.34.
What is the basis for the COLSS LDP POL?
13.1 kw/ft assures that 2200F Tclad is not exceeded on a LOCA = assures that fuel wont melt.
What is used to calibrate the excore NIs?
JSCALOR
What is COLSS made up of?
CMC and PC: both run identical programs simultaneously and can drive either meter in the Control Room (CMC is normally connected)
How are the inputs divided up between the CMC and the PC?
The same inputs go to both computers
What must be done if COLSS is lost?
You have to manually surveil DNBR, LHR, Tilt, and ASI.
How does a loss of the PC affect the CMC?
The CMC will no longer receive pulse counts = no CEA sequencing
What are the inputs to JSCALOR?
Feed Flow
Feed Temp
Steam Flow
Steam Pressure
What are the inputs to NKBDELT?
Tc Th Ppzr RCS Mass Flow Rate: - RCP RPM - RCP D/P
Which inputs in COLSS have redundant sensors that will swap on sensor failure?
RCP RPM RCP D/P Pressurizer Pressure Th Tc Steam Flow (basically everything in the can)
How is the Power Limit Margin (Red LED Meter on B05) determined?
Displays the most restrictive of the difference between current Selected Power and DNBR POL, LPD POL, and the License Power Limit. At 100% power, the most restrictive is the License Power Limit (~101.5%).
Which inputs in COLSS will not swap on sensor failure?
Feed Flow
Feed Temp
Steam Pressure
What COLSS Secondary Power reading gets smoothed to provide JSCALOR?
BSCRAW
What is the equation used to determine Secondary Power?
Qsec = m(hstm - hfw) - gains + losses - SGBD
How does JSCALOR react if the Blowdown Constant is increased?
JSCALOR reads lower.
What is the result of NKBDELT calibrated by JSCALOR?
JCPCAL
How does JCPCAL relate with JSCALOR?
JCPCAL is slowly moved toward JSCALOR (1 hr)
What is used to calibrate NKBTFST? What results?
JSCALOR
NKCBTFST
How does NKCBTFST relate with JSCALOR?
NKCBTFST is slowly moved toward JSCALOR (1 hr)
What does it mean if JSCALOR > NKCBTFST?
It means theres a steam leak somewhere
What does it mean if JCPCAL and NKCBTFST inputs are bad?
It means COLSS is out of service
From what is AZTILT calculated?
Incores
9 calculations at 5 levels
What parts of the AZTILT calculation could put COLSS OOS?
< 75% of incore detectors available
< 3 levels available
< 5 calculations
What happens if AZTILT > CPC value?
Must change the addressable constant in CPC to be more conservative than the COLSS calculated value.
Planar Radial Peaking Factors (Fxy) are computed for _____ levels using CEAs and _____.
20 levels
CEAs and Tc
What is the JSCALOR uncertainty?
2%
How long does it take to fully reflect a JCSALOR error in Plant Power?
about an hour
DNBR POL _________ as ASI gets more negative
lowers
How does Tc deviation from 555F affect POLs?
They all decrease (especially LPD)
Higher RCP D/P means _______ flow and ________ DNBR POL.
lower
lower
If COLSS needs to be restarted, how should this be done?
On one computer at a time
Allow 10-15 minutes for values to stabilize
