RHR

Question 1

What are the RHR pump trips?

Answer 1

• Overcurrent/Overload
• Loadshed
• Lo-Lo RWST w/ RWST suction not fully closed

Question 2

What are the interlocks associated with IMO-310/320 (RHR Suction from RWST)?

Answer 2

• to open: (Train specific): ***
• ICM-305/306 closed
• IMO-330/331 closed
• IMO-340/350 closed

Question 3

What are the interlocks associated with IMO-305/306 (Recirc Sump suction valve)?

Answer 3

• open signal for ESW from CTS HX
• IMO-310/320 closed
• IMO-215/225 closed

Question 4

What is the interlock associated with IMO-128 (ICM-129) (Loop 2 HL RHR suction valve)

Answer 4

• 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 **

Question 5

What are the interlocks associated with IMO-340/350 (RHR HX to CCP suction)?

Answer 5

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**

Question 6

What are the interlocks associated with IMO-330/331 (RHR(CTS) spray valves)?

Answer 6

• ICM-305 (306) open (Train Specific)

Question 7

When will the RHR pump recirc valve open?

Answer 7

• Opens at 820(900)gpm

- Closes at 1335(1500)gpm

Question 8

What does Hot Leg recirc do for the RCS?

Answer 8

• Prevents boron precip in the Rx

Question 9

What are the #s that the RHR safety valves lift at and what does it support?

Answer 9

• RHR Suction Safety 450# (supports LTOP)
• Discharge Safeties - 600#
• Cooldown Line Safety - 600#

Question 10

When is RHR (CTS) Spray used?

Answer 10

• It is only used when there has been a failure of the CTS system
  (< 2 CTS pumps are running)

Question 11

What is the Normal Cooldown flow path for RHR? ***

Answer 11

• 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

Question 12

What is the ECCS lineup for RHR (Cold Leg Injection)?

Answer 12

• 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**

Question 13

What is the Hot Leg Recirc flow path for RHR?

Answer 13

• 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)

Question 14

What are the 4 things that support LTOP?

Answer 14

• RHR suction Safety (goes to PRT)
• 2 Pzr PORVs (Goes to PRT)
• RCS Vent
• NPS-122/121 (RCS WR #)

Question 15

What is the Cold Leg Recirc Flowpath for RHR?

Answer 15

• 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

Question 16

Where does IRV-300 discharge to and where does it tap off the RHR system??

Answer 16

• Discharges to Inlet of the LD Hx

- Taps off after the RHR Hx before IRV-310/320

Question 17

What are the RHR auto starts?

Answer 17

• SI

- Load shed with SI

Question 18

When is RHR placed into service after a Rx Shutdown?

Answer 18

• RHR placed into service approx. 4 hours after Rx shutdown when # and temp of RCS are approx. 400# and < 350°F

Question 19

Why is there a minimum time 5.5 hours and 7.5 hours for Hot Leg Recirc?

Answer 19

• Avoid core uncovery due to boil off

Question 20

Why must you close RHR Loop Injection Valves prior to aligning RHR Spray?

Answer 20

• Prevents RHR Pp’s from running out

Question 21

____ valve goes to ____ instrument goes to ____ Loop. (insert “Even” and/or “Odd” as applicable

Answer 21

• Even valve goes to even instrument goes to odd loop

Question 22

Can we run BOTH RHR Pp’s at reduced inventory?

Answer 22

• We can only run 1 RHR pump @ Reduced Inv because we could cause air entrainment at Loop 2 suction due to vortexing

Question 23

If have air entrainment from RHR reduced inventory, how/where do you vent?

Answer 23

• Vent bottles staged at Loop 2 suction vent (RH-138) and in pump room

Question 24

On an SI what does the CCW outlet from the RHR Hx throttle to?

Answer 24

• 3000-3500 gpm

Question 25

What is the weak RHR pump is protected by?

Answer 25

• RHR Hx discharge check valve (Still has recirc flow)

Question 26

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.

Answer 26

C. can, ICM-306, IMO-331 & IMO-350 are closed

Question 27

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

Answer 27

C. IMO-262 or IMO-263, SI Pumps Recirc to RWST - CLOSED