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 –> IMO-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 is the Cold Leg Recirc Flowpath for RHR?

Answer 14

• Manually aligned by Operators (RWST < 20%)
• Water from recirc sump thru IMO-305/306
• IRV-310/320 –> ICM-311/321 –> IMO-316/326
• IMO-314/324 are closed during transfer to Recirc phase to provide train separation
• RHR discharges to loops 1-4 CLs

Question 15

When is RHR placed into service after a Rx Shutdown?

Answer 15

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

Question 16

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

Answer 16

• Avoid core uncovery due to boil off

Question 17

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

Answer 17

• Prevents RHR Pp’s from running out

Question 18

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

Answer 18

• Even valve goes to even instrument goes to odd loop

Question 19

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

Answer 19

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

Question 20

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

Answer 20

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

Question 21

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

Answer 21

• 3000-3500 gpm

Question 22

What is the weak RHR pump is protected by?

Answer 22

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

Question 23

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 23

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

Question 24

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 24

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

Question 25

What enables the lo-lo RWST level trip (9%) of an RHR pump

Answer 25

• IMO 310/320 (RWST to the RHR PP) in the open position