Pressurizer system Flashcards
PZR program level and program Tave for each unit:
Unit 1 25-60% 557-586.5F
Unit 2 27-60% 557-581F
What is/are the purpose(s) of the pressurizer?
A: Maintain RCS press, accommodate transients, FP barrier
Why is water level in the PZR programmed to vary with RCS average temperature?
A: Minimize the mass xfer in and out of the RCS. This minimizes impact on CV when changing power
What is the design flow and setpoint of the PZR safeties based on?
A: Complete loss of load, with S/G safeties and FW flow, with: No Rx Trip, auto rod movement, No RY PORVS, No Steam dumps or MS PORVS, No RY level control actions or RY Sprays
What is the setpoint of the PZR safeties?
2460 psig
PZR contains about _____gallons per % level
120
Safety function of PORVs
LTOP
List PZR operational design criteria:
A: 5%/min w/o Rx Trip and Rods in Auto, 10% step change w/o Rx Trip or uncovering heaters, 50% step load reduction w/ rods in auto and steam dumps. Complete loss of load with Rx trip due to Hi PZR level and no water out safeties
PZR backup heaters auto energize when _____% above program level. This _________.
> =5%; Heats cold water from an insurge to saturation
PZR heater group setpoints, KW rating, and power supplies
A 21 on 2220 1400 KW 143 B 21 off 2225 144 C 18 full on 2220 400 KW 144 full off 2250 D 18 143
At PZR level of_____pzr heaters auto shutoff. Backup are _____reset. Variable are _______reset.
<17%. Backup heaters auto reset, variable must be reset manually.
PZR spray valves start to open at ______. Full open at ______.
2260psig; 2310 psig
Bypass flow to:
Max temp difference for spray:
Keep spray and surge lines warm
Mix Pzr and RCS
Prevent thermal shocking spray nozzle
Spray/Pzr vapor Delta T limit of 320°F
RY 455A opens at ______
RY 456 opens at________
Both reset at ______
2345#
2335#
2315#
PORV interlock setpoint_______
2185#
PRT rupture disc breaks at _____ psid
100 psid
RCDT level tree
60% RE 1003 opens, A pump starts
80% B pump starts
38% RE 1003 closes, B pump stops