RHR

Question 1

RHR-8700A(B)….what is it?
Interlocks?
Purpose o interlocks

Answer 1

• RHR pump suction valves
• cannot open unless SI-8804A(B), SI-8982A(B) and CS-9003A(B) are closed
• 8982….drain RWST to floor (CNMT recirc sump)
• 9003….spray cnmt with hot RCS
• 8804….X-conn SI suct

Question 2

RHR8701……what is it?
Interlocks …..?
Why……?

Answer 2

Normal connection RCS HL(4) to RHR

• cannot open unless Prcs < 390 psig & vap temp < 475 deg(Pzr stm)
• prevent over pressurizing RHR w/RCS

Question 3

RHR-8702…….what is it?
Interlocks…..?
Why………..?

Answer 3

Normal connection RCS hL (4)->RHR

• cannot open unless Prcs < 390 psig
• prevent over pressurizing RHR w/RCS

Question 4

Sources of water to RHR pumps?

Answer 4

RWST
CNMT recirc sump
RCS hL 4

Question 5

RHR Pump auto starts

Answer 5

SI signal

Question 6

RHR pump Auto Stop

Answer 6

Overcurrent
Transfer to Diesel
RWST <33% (2/3 coincidence)
-defeated if 8982a/b is open
-defeated if in local at breaker
-bypassed by RWST low level trip test switch (csr) for filling the refueling cavity

Question 7

RHR shutoff head, design flow, runout flow

Answer 7

173 psid
3000 gpm
4500 gpm

Question 8

RHR place in service

Answer 8

<350F (Mode 4)
<390 psig

Question 9

Interlocks to open 8700A/B (RHR pump isolation)and why?

Answer 9

To Open
-8982A/B closed
-9003A/B closed
-8804A/B closed

To prevent transferring water to CVCS,Spray,or Sump during normal ops

Question 10

8701/8702 (RCS Loop 4 HL Suction Isolation and why the interlocks

Answer 10

To open 8701
-pt-405a<390 psig
-pzr steam space <475F

To open 8702
-pt-403a <390 psig

Interlocks to prevent rhr over pressurization
Normally power removed, during shutdown power on in case closure needed for inter-system LOCA

Question 11

FCV-641A/B RHR P Recirc Valves open and close at what flow

Answer 11

Open at <728 gpm
Close at >1398 gpm

Question 12

HCV-638/637/670 RHR Flow Control & HX Bypass valves fail and have what thats special

Answer 12

fail open and have mechanical stops to prevent RHR Pump Runout

Question 13

8809A/B RHR to Cold Legs have what special feature

Answer 13

series contactors to prevent inadvertent operation

Question 14

8716A/B RHR Discharge Cross Tie are in what position and why

Answer 14

normally open to allow one RHR PP to feed all four cold legs

Question 15

HCV-133 RHR HX Outlet to CVCS Letdown is used when?

Answer 15

When RCS pressure is too low to provide sufficient flow through normal letdown

Question 16

RV-8707 RHR Suction Relief setpoint, capacity,
reliefs to, purpose

Answer 16

Setpoint: 450 psig
Capacity: 900 gpm
Reliefs to: PRT
Purpose: protect suction line from over pressurization

Question 17

RV-8708 RHR Discharge Relief setpoint, capacity,
reliefs to, purpose

Answer 17

Setpoint: 600 psig
Capacity: 20 gpm
Reliefs to: PRT
Purpose: protect discharge from thermal expansion and back leakage

Question 18

8982A/B containment Sump Recirc Isolation has what special feature and has what interlocks

Answer 18

series contactors to prevent inadvertent operation

to open
- 8700A/B Closed

Interlock to prevent inadvertant transfer of sump water to rwst or rwst to sump

Question 19

9003A/B Containment Spray Isolation interlocks and purpose of interlock

Answer 19

to open
- 8701 or 8702 closed
-8982A/B open
interlock to prevent inadvertent spray during normal ops and assure RHR is in recirc mode during accident conditions

Question 20

8804A/B RHR Discharge to SI/CCP Pumps interlocks and purpose

Answer 20

to open
-8974A or B closed (SIP recirc)
-8701 or 8702 Closed
-8982A/B Open

Interlock to prevent inadvertant transfer of sump water to rwst or rcs tp rwst and assure RHR is in recirc mode during accident conditions