Pressurizer Flashcards
The Surge line for the pressurizer taps into the RCS where?
Loop 3 Hot Leg
What is the level to gallons ratio at NOP/NOT?
50.56 gals per 1%
What are your cooldown limits? Admin limits?
200°F per hour (Admin of 195°F/hr)
What are you heatup rate limits? admin?
100°F/hr (Admin 95°F/hr)
On insurge of RCS into Pressurizer (PZR insurge) what happens?
Pressue and Temperature RISE to maintain T(sat) and P(sat) conditions.
On outsurge of Pressurizer into the RCS what happens?
Pressure and Temperature Lower to maintin T(sat) and P(sat) conditions
The Pressurizer control heaters are powered from?
480V Bus 2B
What controls (turns off/on) the Control heaters for the pressurizer?
PC-444J, based on pressure of 2235(±15psig) from PT-444
What are the breaker trips for the Control Heaters for the PZR?
- PZR low level @ 14.4% (does not reset automatically, must take switch to off to reset)
- Overcurrent
PZR B/U heaters power supplies are?
B/U group A powered from 480V Bus1
B/U group B powered from 480V Bus2A
While in auto, what is the B/U PZR heaters operating parameters? from what controler?
In auto they operate from 2210-2220psig from PC-444J
B/U PZR heaters breaker trips are?
- PZR low level @ 14.4% (will not come back on automatically, must take switch to off to reset) In ON heaters trip on low level from the LT-460 only, in AUTO heaters trip on low level from LT-460 & LT-459
- Overload
B/U heaters can be controled locally where?
Locally controlled in Rod Drive Control Room. (Removes auto functions)
What is the ITS requirments for KW if on emergency power to be supplied to PZR heaters?
ITS requires 125KW, EPP-21directs 150KW from an E-bus.
Where is the PZR HTR ARMING SWITCH?
It is on the Miscellaneous Relay Rack 50 (Will trip open the heater supply breaker if a subsequent SI is recieved to prevent overloading an EDG)
What are the backup power supplies to the heater groups?
- Control group can be powered from “B” EDG & DSDG
- B/U group A can be powered from “A” EDG
What are the PZR Spray Valves?
- PCV-455A off of Loop 2 cold leg, must have 30% PZR level and “B” RCP running
- PCV-455B off of Loop 3 cold leg, must have “C” RCP running
- CVC-311- Aux Spray from Charging , Max 320°F ▲T between PZR and spray to prevent thermal shock to nozzels.
PZR spray valves start to open and close when? Controled by?
- Start to open @2260psig, fully open @ 2310psig
- Start to close @ 2285psig, fully closed @ 2235psig
- In auto controlled by PC-444J
What is the purpose of the PZR spray valves bypass flow?
0.5gpm through needle valves to keep line warm and prevent thermal shock, also provideds a way for mixing with RCS to keep boron concentraion with in 10ppm.
If a safegaurds (Phase A) actuation happens how does this effect the PZR spray?
Phase A closes PCV-1716, meaning no IA to CV, and all PZR spray valves fail closed.
How many PZR safety valves?
3
At what pressure do the safetys open?
2485psig (RCS design pressure)
Where are the acoustic monitors for the PZR safety vavles?
Cable spread room
How many PZR PORVS?
2
What is the mode of force for the PORVs?
N2
PCV-455C (PZR PORV) when does open? Powered by?
Opens at 2340psig
Powered from DP “B”
PCV-456 (PZR PORV) when does it open? Powered by?
Opens at 2235psig
Powered from DP “A”
PORV Black Valves are powered from?
MCC-6
LTOPP (Low Temperature Over Pressure Protection) does what?
Changes the PORV pressure setpoint to varibale no lower than 400psig
When is LTOPP used?
When <365°F
PZR lvl Control transmitters?
- LT-459
- LT-460
- LT-461 (Can do either of the other two LT’s, acts as a backup)
HI level trip is caused by?
LT-459/460/461 (2/3) at 91% above P7
Level programing (Parameters of lvl to Tavg)
lvl in PZR from 0% to 100% power
- 22.2% level in PZR at 0% power
- 53.3% level in PZR at 100% power
you can use this to find the lvl or power if you have one or the other
ITS requirements for the PZR?
- ≤63.3% in mode 1
- ≤92% in modes 2 or 3
- Always have ≥125kw of heaters from E-bus
LT-459 controls what?
- Level in the PZR by controlling Charging pump speed
- Gives HI and LO lvl alarms +/- 5% from program.
- At +5 lvl will turn on B/U heaters anticipating an insurge.
- At 14.4% cuts off control heaters and B/U (if in auto) also shuts LCV-460A/B
LT-460 controls what?
At 14.4% cuts off control heaters and B/U heaters (in auto or on) also isolates letdown
LT-461 controls what?
Backup LT, will perform all functions of what LT it replaces.
PZR, PTs for protection?
- PT-455
- PT-456
- PT-457
PZR, PTs for control?
- PT-444
- PT-445
PT-455, 456, 457 do what?
- 2376psig (2/3) Hi Pressure Rx trip
- 2000psig (2/3) Premissives for SI black and Closes PZR PORV’s (when in auto)
- 1844psig (2/3) Low Pressure trip
- 1715psig (2/3) Low pressure SI
- Input to OT▲T trip and runback
PT-444 does what?
- Pressure indication on the RTGB, and at the MDAFW pump station
- Signals to proportaional integral controller (PC-444J) on RTGB
- Opens PVC-455C (PORV) (@2340psig)
PT-445 does what?
- Singals PZR CNTRL HI & LO press alarms on RTGB
- Opens PCV-456 (PORV) (@2335psig)
- Indication on the RTGB
PC-444J controls what?
- Control Group heaters +/-15psig
- Back up heaters 2220-2210psig
- Spray Valves
- PI-458 to indicate +/-15
If LT-459 fails high what happens?
- If in auto charging pump drops to min. speed
- B/U heaters in auto energize
- PZR HI LVL, and PZR protection & Control HI level alarms
- Actual PZR level lowers causing letdown isolation and all heaters to turn off at 14.4% (Auto or manual) (LT-460 causes this)
- PZR presssure slowly falls due to lack of heaters.
- 15.4% signal resets, can mannually restore letdown and heaters.
LT-459 failing high does different trips base on power level.
- High Power- OT▲T trip
- Low power- Low pressure trip at 1844psig
- Power <P-7- pressure would decrease to SI setpoint 1715psig
LT-460 fails high what happens?
PZR protection high level alarm and bistable
LT-461 fails high what happens?
PZR protection high level alarm and bistable
LT-459 fails low, what happens?
- If in auto, charging pump max speed
- 14.4% letdown isolation and all heaters off (B/U if in auto)
- Low PZR Level alarm and bistable at 10%
- Actual PZR level increases (at 91% 2/3 get Reactor trip if >p-7)
LT-460 fails low
1.If in auto, charging pump max speed
2.14.4% letdown isolation and all heaters off (B/U if in auto)
3.Low PZR level alarm and bistable at 10%
4.Actual PZR level increases (at 91% 2/3 get Reactor trip if >p-7)