RHR Flashcards
What are the RHR pump trips?
- Overcurrent/Overload
- Loadshed
- Lo-Lo RWST w/ RWST suction not fully closed
What are the interlocks associated with IMO-310/320 (RHR Suction from RWST)?
- to open: (Train specific): ***
- ICM-305/306 closed
- IMO-330/331 closed
- IMO-340/350 closed
What are the interlocks associated with IMO-305/306 (Recirc Sump suction valve)?
- open signal for ESW from CTS HX
- IMO-310/320 closed
- IMO-215/225 closed
What is the interlock associated with IMO-128 (ICM-129) (Loop 2 HL RHR suction valve)
- RCS # < 411#
(NPS-122 gives signal to IMO-128 from RCS WR Loop 1 #)
(NPS-121 gives signal to ICM-129 from RCS WR Loop 2 #) ** - Alarm comes from the instrument that isn’t failed **
What are the interlocks associated with IMO-340/350 (RHR HX to CCP suction)?
Will not open unless:
- ICM-305 (306) are open
- IMO-262/263 are closed (with Ctrl Pwr on)
- Ensures that water cannot be transferred from Recirc Sump to RWST**
What are the interlocks associated with IMO-330/331 (RHR(CTS) spray valves)?
- ICM-305 (306) open (Train Specific)
When will the RHR pump recirc valve open?
- Opens at 820(900)gpm
- Closes at 1335(1500)gpm
What does Hot Leg recirc do for the RCS?
- Prevents boron precip in the Rx
What are the #s that the RHR safety valves lift at and what does it support?
- RHR Suction Safety 450# (supports LTOP)
- Discharge Safeties - 600#
- Cooldown Line Safety - 600#
When is RHR (CTS) Spray used?
- It is only used when there has been a failure of the CTS system
(< 2 CTS pumps are running)
What is the Normal Cooldown flow path for RHR? ***
- Loop 2 HL
- IRV-311 used in conjunction with IRV-310/320 to control flow, temp and cooldown rate
- Thru ICM-111 to Loop 2 and 3 CLs (Thermal Sleeves)
- Preferred flow path when RCS temp > 200°F
What is the ECCS lineup for RHR (Cold Leg Injection)?
- RHR Pumps take suction from RWST (IMO-390)
- IRV-310/320 –> ICM-311/321 –> IRV-316/326
- IMO-314/324 must be open for 4 Loop CL injection
- Enters loops 1-4 CLs
- No valves need to re-position**
What is the Hot Leg Recirc flow path for RHR?
- Injection switched to HLs by opening IMO-315/325 and IMO-316/326 are closed (Must be closed first and SI pumps must be shut off due to recircs being closed)
What are the 4 things that support LTOP?
- RHR suction Safety (goes to PRT)
- 2 Pzr PORVs (Goes to PRT)
- RCS Vent
- NPS-122/121 (RCS WR #)
What is the Cold Leg Recirc Flowpath for RHR?
- Manually aligned by Operators (RWST < 20%)
- Water from recirc sump thru IMO-305/306
- IRV-310/320 –> ICM-311/321 –> IRV-316/326
- IMO-314/324 are closed during transfer to Recirc phase to provide train separation
- RHR discharges to loops 1-4 CLs
Where does IRV-300 discharge to and where does it tap off the RHR system??
- Discharges to Inlet of the LD Hx
- Taps off after the RHR Hx before IRV-310/320
What are the RHR auto starts?
- SI
- Load shed with SI
When is RHR placed into service after a Rx Shutdown?
- RHR placed into service approx. 4 hours after Rx shutdown when # and temp of RCS are approx. 400# and < 350°F
Why is there a minimum time 5.5 hours and 7.5 hours for Hot Leg Recirc?
- Avoid core uncovery due to boil off
Why must you close RHR Loop Injection Valves prior to aligning RHR Spray?
- Prevents RHR Pp’s from running out
____ valve goes to ____ instrument goes to ____ Loop. (insert “Even” and/or “Odd” as applicable
- Even valve goes to even instrument goes to odd loop
Can we run BOTH RHR Pp’s at reduced inventory?
- We can only run 1 RHR pump @ Reduced Inv because we could cause air entrainment at Loop 2 suction due to vortexing
If have air entrainment from RHR reduced inventory, how/where do you vent?
- Vent bottles staged at Loop 2 suction vent (RH-138) and in pump room
On an SI what does the CCW outlet from the RHR Hx throttle to?
- 3000-3500 gpm
What is the weak RHR pump is protected by?
- RHR Hx discharge check valve (Still has recirc flow)
The following plant conditions exist:
- IMO-320, West RHR Pump Suction - closed
- IMO-390, RHR Pumps Suct from RWST - closed
- IMO-128 and ICM-129, RHR Returns from Hot Leg 2 - open
- ICM-306, Recirc Sump to West RHR/CTS Pumps - closed
- IMO-331, West RHR Spray to Upper Containment - closed
- IMO-350, SI Pump Suction from West RHR Heat Exchanger - closed
- RWST level is 7% and stable
Assuming electrical power is available, IMO-320 _______ be opened because _______.
A. can, IMO-390 & ICM-306 are closed.
B. cannot, RWST level is too low.
C. can, ICM-306, IMO-331 & IMO-350 are closed.
D. cannot, IMO-128 & ICM-129 are open.
C. can, ICM-306, IMO-331 & IMO-350 are closed
While shifting to cold leg recirc during a LOCA, IMO-350, SI Pump Suction from West RHR Hx, will NOT open.
Which ONE of the following conditions must be established to allow IMO-350 to be opened?
A. IMO-361 and IMO-362, SI Pump Suction Cross-Ties to CCP - OPEN
B. IMO-320, West RHR pump Suction - OPEN
C. IMO-262 or IMO-263, SI Pumps Recirc to RWST - CLOSED
D. IMO-261, SI pump Suction From RWST - CLOSED
C. IMO-262 or IMO-263, SI Pumps Recirc to RWST - CLOSED
