Pre-course ILT RH

Question 1

What are the various functions of the RH system?

Answer 1

Remove heat from the core during the second phase of plant cooldown
Serve as the low pressure high volume segment of ECCS
Transfers refueling water between the RWST and refueling cavity

Question 2

What is the design basis of the RH system?

Answer 2

Placed in operation 4 hours after shutdown <350F and <360psig
Reduced RCS temp from 350F to 140F within 36 hours (2 trains)
Reduce RCS temp from 350F to 200F within 44 hours (1 train)
Uses 5000 gpm CC flow at 105F max temp
ECCS operation available for 1 year following LOCA with single failure

Question 3

What is the flowpath of the RH system during ECCS injection during modes 1-3?

Answer 3

RWST –> SI8812 –> RH PP –> RH HX –> RH606 –> RH8809 –> A & D Cold Legs

Question 4

What is the flowpath during normal alignment in Mode 4?

Answer 4

One train in ECCS injection and one train on SDC.

Question 5

What is the flow path of Mode 6 alignment during cavity fill?

Answer 5

One train on SDC: Hot leg –> Cold Legs & CVCS
One train on cavity fill: RWST –> Hot Legs A&C

Question 6

What is the flow path alignment during Mode 6 cavity drain?

Answer 6

One train on SDC: A Hot Leg –> Cold Legs A&D & CVCS
One train on cavity drain: Hot Leg C –> RWST

Question 7

Why is a portion of RH flow diverted to the CVCS during shutdown cooling operations?

Answer 7

Permits clean up of RCS during RH operation
Pressure control of RCS with pressurizer water solid
Used for letdown of RCS when pressure is too low

Question 8

What is the RH pump design flow and pressure?

Answer 8

3000 GPM @ 165 psid

Question 9

What is the RH pump runout flow and pressure?

Answer 9

5000 GPM @ 125 psid

Question 10

What is the shutoff head of the RH pump?

Answer 10

200 psid

Question 11

When do the RH system relief valves lift?

Answer 11

Suction 450 psig
Discharge 600 psig

Question 12

When is the RH system placed into operation?

Answer 12

<350F and <360 psig after 4 hours of shutdown

Question 13

How is RCS temp controlled while utilizing RH on SDC?

Answer 13

Bypass valve automatically controls to maintain 3300 gpm
HX outlet valve 606 & 607 manually adjusted to maintain cooldown rate

Question 14

What setpoints and operations do the mini flow recirc valves operate on?

Answer 14

A flow element on the discharge line senses when to operate valve; open <750 gpm, closes >1400 gpm

Question 15

What controls for the Rh system are available on the RSDP?

Answer 15

None, temperature instrumentation is locally mounted in the RH HX rooms