LPCI

Question 1

What is the purpose of LPCI?

Answer 1

Prevent fuel cladding from exceeding any thermal limits (>2200F APLHGR Limit) as a result of a LOCA for break sizes where core is adequately cooled by HPCI, up to and including DBA line Break

Question 2

Where does LPCI normally take suction from? Alternate? Suction Limitations?

Answer 2

ECCS Ring Header off Torus.

Alt: CST - but only one pump can be lined up at a time.

Question 3

Where does LPCI Injection normally discharge to on injection?

Answer 3

Discharged to recirc pump discharge line and into jet pumps

Question 4

What other system injects into the LPCI Injection Line?

Answer 4

Shutdown Cooling ties into LPCI line upstream of check valve that divides LPCI and recirc systems

Question 5

Where does the LPCI Min Flow line route to?
What are the open and close setpoints?
What is it’s normal position?

Answer 5

Min Flow Line routes water to LPCI Test Line in Torus.
It closes at 1300gpm flow.
Opens at 1211 gpm flow and pump running on that side.
The Min Flow valve is only open when pump is in standby?

Question 6

What is the pump/injection condition required for min flow to be active?

Answer 6

Pump in standby or Pump running and less than 1300gpm flow.

Question 7

Where are the LPCI Pumps powered from?

Answer 7

2A/B powered from 23-1

2C/D powered from 24-1

Question 8

What is the standard flow for LPCI with a single pump and 2 pumps running?

Answer 8

1 pump : 5000gpm

2 pump : 9000gpm

Question 9

What is the LPCI pump oil cooler cooling?

Answer 9

Its own pump discharge

Question 10

Where are the LPCI system valves primarily powered from? Which are not powered from here and what are they powered from??

Answer 10

Most valves powered from 28-1/29-4 (38-4/39-1). The injection valves -21/22 - are powered from 28-7/29-7 (38-7/39-7)

Question 11

Where can the LPCI valves be manipulated from?

Answer 11

MCR, Local control stations, the valve itself

Question 12

What does the LPCI Cross Tie do?

Answer 12

Provides so the A & B Loops can be cross tied together. This is required to be open for system operability.

Question 13

What provides the LPCI Keepfill?

Answer 13

ECCS Jockey Pump

Question 14

What is the approximate heat removal capability of the LPCI Hx and what provides the cooling?

Answer 14

~20MWth - cooling from CCSW

Question 15

For minimum safety analysis how many CCSW Pps, Hx, and LPCI Pps are required

Answer 15

Min 2 CCSW Pps, 1 Hx, and 1 LPCI Pp all in the same loop

Question 16

What is the normal operation of the HX upon LPCI Start/initiation?

Answer 16

Bypassed through N.O. bypass valve, which is interlocked open for 30 seconds on initiation signal

Question 17

What is normal pressure of CCSW compared to LPCI?

Answer 17

CCSW ~20psid>LPCI - controlled via outled valves

Question 18

What is the normal power source and all cooling water sources to ECCS ROOM COOLERS?

Answer 18

Powerd by MCC 28-1/29-4(38-1/39-1)

Cooling from SW, CCSW, or DGCWP (INops EDG)

Question 19

What are the alternate flow paths for LPCI?

Answer 19

Torus Spray, DW Spray, Test/Torus Cooling

Question 20

What is the normal flow for Torus and DW sprays?

Answer 20

5000gpm total - 4750gpm DW Spray, 250 Torus Spray

Question 21

What is the normal position of the Torus Spray and DW Spray valves? Are they throttleable when opened?

Answer 21

The are all normally closed.

DW Spray not throttleable, Torus spray valves are throttleable

Question 22

Which valves are in the LPCI Injection Path? Where are they? What is normal position? what kind of valve are they?

Answer 22

21 vlv - norm open - throttle globe valve - first injection valve
22 vlv - norm clsd - open/closed gate - second injection
25vlv - nom closed chk vlv - in DW - pos ind. in DW

Question 23

Where are the LPCI Flow elements and what do they do? What is the power source for the FLow Transmitters?

Answer 23

2 FE/FI/FT upstream of 21 valve
Shows only injection or Test flow
A - loop powerd by IB
B - loop powered by ESS

Question 24

WHAT ARE THE LPCI INITIATION SIGNALS?

Answer 24

2# DW Pressure

• 59” and <350# Pressure
• 59” for 8.5 Min

Question 25

What is the purpose and logic for LPCI Loop Select?

Answer 25

Chooses which LPCI/RR Loop to inject into. Upon initiation - If <2RR Pps running, trip both and wait for 900psig RPV Pressure After 900psig or if both RR were running - Is A riser 1psid>B riser If yes, then B loop determined in broke and A chosen for injection. Otherwise B is default.

Question 26

What valve/pp manipulations are performed automatically upon selection of loop for injection?

Answer 26

Selected Loop: RR Pp Discharge vlv closes and Pp trips. | Opp loop - LPCI Inject vlvs close

Question 27

Why does LPCI Loop Logic required to limit RR Pump Speed mismatch?

Answer 27

TO ensure no confusion during loop selection - cannot compare running pump to a line break

Question 28

Upon Initiation signal, what is the LPCI valve response?

Answer 28

Suction Valve interlock open Hx Bypass interlock open 30 sec Nonselected loop inject vlvs interlock closed - can be overridden by 316/317 keylock Selected loop 21 & 22 vlvs open at <350# RPV Press - 21 vlv interlocked full open for 5 min -can be bypassed.

Question 29

What is the purpose of the 316/317 keylock switches?

Answer 29

316 allows reopening of 21 vlv for torus cooling if needed | 317 can be used if level

Question 30

What is the Test Line, and DW/Torus Spray Response on initiation?

Answer 30

Vlvs interlock closed to maintain flow to core - can be overridden by 316 keylock If lvl

Question 31

What is the CCSW response to LPCI Initiation?

Answer 31

CCSW Pps trip - 318 keylock used to bypass trip and start pumps

Question 32

What is response of LPCI to initiation with LOOP?

Answer 32

``` Will have a logic delay based on EDG starting. 10 seconds to start and close breaker 3 seconds to reset UV relays 1st pp starts immediately 2nd pp starts 5 sec later CS Pp starts 5 sec later ```

Question 33

What are the injection vlv interlocks?

Answer 33

>350#, 21 vlv can be opened if 22 closed 22 vlv can be closed if both 21 and 38 closed Below 350#, both 21 and 22 can open at same time

Question 34

What powers the Loop Select Locic?

Answer 34

Div I /II 125VDC power

Question 35

What happens on a loss of Div I 125VDC (2A-1)(3A-1) power to LPCI?

Answer 35

``` Div I Pps not auto start Div I vlvs not auto position No -59 sig to HPCI No 2# signal to CS A logic 21/22 vlvs WILL reposition based on Div II loop select because powered by 28-7/29-7 whcih auto swap. ```

Question 36

What are trips of LPCI Pumps?

Answer 36

Overcurrent or Bus UV

Question 37

What provides level indiation/signal upon LOCA and ECCS initiation?

Answer 37

Fuel Zone

Question 38

What happens to LPCI on loss of Div II 125VDC power?

Answer 38

Div II Pps not auto start Div II Vlvs not auto position 21/22B vlvs WILL repositon based on Div I loop select NO 2# signal to CS B logic

Question 39

What will loss of single division Loop Select Logic have on ability to detect break or cycle valves?

Answer 39

None - will power from other division.

Question 40

What happens if you lose more than 1 LP ECCS Subsystem?

Answer 40

ENter 3.0.3.