Pzr Pressure and Lvl Control Flashcards
What is the normal Lvl, temp, and # of the PRT? **
- 100°F
- 83%
- 3#
When will the PRT vent valve not open?
- If # is > 10#
What is the max # of the PRT?
- 100# (Rupture Disk)
What is the PRT designed to do?
- Condenses 110% of Pzr steam space
- Protects the Rx Vessel against brittle fracture during LTOP conditons
- Provides overpressure Protection
What are the inputs to the PRT?
- Pressurizer Safeties and PORVs
- Seal Water Return Safety
- CCP Suction Safeties
- ECCS Safeties
- RHR Suction Safety
- RHR Hot Leg Discharge Safety
- RHR hx Safeties
- PW and N2
What is the design of the Pzr Lvl and # Ctrl?
Designed to accommodate:
- unit load change @ 5% / minute.
- Instant load changes @ 10% w/ auto rod control.
- step load reduction @ 50% w/ auto rods and dumps
What is the lvl per percent in the Pzr?
- 75gal/1% **
What is the Pzr Lvl Program based on?
- Based on Auctioneered High Tave
- Unit 1 - 22% to 50% (28% diff)
- Unit 2 - 22% to 55% (33% diff)
- Both Units Trip at 92% (2/3)
What are the Pressure inputs for the Pzr # Ctrl?
- NPP-151/152/153 NPS-153
- NPP-151 input to QMO-225 (East CCP ELO)
- NPP-153 input to QMO-226 (West CCP ELO)
- If Channel III (NPP-153) is controlling channel and it fails low all PORVs are Inoperable
At what pressure do the Pzr Safeties lift?
- 2485# (SV-45A/B/C)
At what pressure do the Pzr PORVs open?
- 2335# (NRV-151/152/153) **
Which Pzr PORVs have backup air bottles?
- NRV-152/153
What supplies the PRT with water if it needs to be filled or if it gets > 126°F during normal ops?
- PW
Which Safeties and PORVs have acoustic monitors?
- Safeties- 1 monitor for each safety valve (3 total)
- PORVs- 1 monitor total (combined)
What are the Lvl inputs for the Pzr Lvl Ctrl?
- NLP-151 (Ctrl Channel)
- NLP-152 (Bistable)
- NLP-153 (Either Ctrl or Bi)
- NLI-151 (cold cal)
What is the Pressurizer Lvl Rx Trip?
- 92% Pzr Lvl
What are the Pzr Spray Bypass valves for?
Allow continuous flow for:
- PZR boron concentration same as RCS
- Minimize PZR temp stratification
- keep spray lines equilibrium with RCS loops.
What are the Pzr Cycling Heater trips?
- Loadshed on same train
- Pzr Low Level @ 17%
- Overcurrent
- Both trains of Supply Breakers closed
- Load Con
- interlock- can’t close both feeder breakers
What is the interlock associated with the Pzr Cycling Htrs?
- can’t close both feeder breakers (Protects EDGs from overloading)
What provides Cold Overpressure protection with the Pzr PORVs?
- NRV-152 controlled by NPS-122 (Loop 1 WR)
- NRV-153 controlled by NPS-121 (Loop 2 WR)
If there is a leaking PORV, what can it affect?
- could lead to PRT rupture disk failure
What are the Pzr backup Heater trips?
- Loadshed on same train
- Pzr Low Level at 17%
- Overcurrent
What are the important pressure setpoints for the Pzr?
2735# - Max Limit 2485# - Safeties Open 2385# - Rx Trip 2335# - PORVS open 2235# - Normal Ops 2200# - DNB 1950# - Rx Trip 1910# - P11 Block 1775# - SI
What can happen if Channel III (NPP-153) is controlling channel for Pzr # Ctrl and it fails low?
- all Pzr PORVs will be Inoperable and the only protection for Overpressure on the Pzr will be the safeties