Intake Cooling Water Flashcards
Discuss ICW Loads – essential vs. non essential header.
Unit 1
* CCW - essential
* CW Pump Lube Water: On essential header
* TCW – non essential
* OBHX – non essential
* SFP – Emergency supply
Unit 2
* CCW - essential
* CW Pump Lube Water: On NON-essential header (lost on SIAS, auto swaps to Dom. Water by pressure switch)
* TCW – non-essential
* OBHX – non-essential
* SFP – Emergency supply
Discuss ICW Pump power supplies.
Unit 1
* A – 1A3 4160V
* B – 1B3 4160V
* C – 1AB 4160V
Unit 2
* A – 2A3 4160V
* B – 2B3 4160V
* C – 2AB 4160V
Discuss NOP-21.03 Precautions and Limits for ICW.
- Pump max flow – 21,600 gpm
- Admin Limit – 18,500 gpm
Higher flow = higher electrical draw on EDG than Loading assumptions –> renders EDG inop. - CCW HX max flow – 18,500 gpm
- Open pump discharge valve 10 turns when starting pump on a depressurized header
Discuss ICW Pump Auto Start Signals.
- SIAS (not flag dependent)
- LOOP (if red flagged)
Discuss ICW Pump Intake wells.
- A Pump – A1 Well
- C Pump – A2 Well
- B Pump – B1 Well
- ICW Pumps suction at -18.5’ el. (lower than CW, so CW can’t rob it)
Discuss ICW Pump EDG Load Blocks.
- A & B – 9 sec on LOOP
- C – 9 second on all starts
Discuss ICW ‘C’ Pump preferred Alignment for App R.
Unit 1
* ‘B’ Header
Unit 2
* ‘A’ Header
Discuss ICW Pump Auto Start Logic.
A’ or ‘B’ Pump:
- Will re-start on a LOOP only if Control Switch is Red Flagged
- Will re-start on SIAS regardless of flagged position, provided they are not in PTL
C Pump will start in place of A or B on a SIAS or LOOP only if:
- The A or B pump control switches are in PTL and;
- The ‘C’ pump is powered is powered from the same train as the pump in PTL (AB 4160 Bus aligned to the proper train)
On a LOOP specifically:
* ‘A’, ‘B’, or ‘C’ Pump breakers will re-close on the 9 second load block
Discuss ICW/CCW Third Pump Interlock Failure.
Unit 1 Only
* {ICW / CCW third pump interlock failure}, monitors power to relays that align C CCW and ICW pumps for SIAS or LOOP starting in place of A or B pumps
* Loss of 1MA or 1MB control power to the “C” pump interlock circuits for CCW and ICW will:
1) prevent auto start on SIAS, and
2) will prevent auto re-start after LOOP if previously running.
* The “C” ICW / CCW pumps can be manually started.
What prevents the ICW headers from collapsing during draining activities?
Vacuum breakers.
Discuss ICW Pump Intake Structure Ventilation.
Unit 1
None
Unit 2
* HVE-41 A & B (Safety Related)
* A5 / B5 MCC
Discuss ICW Non-Safety Header Isolation Valves
* MV-21-3 (A Train)
* MV-21-2 (B Train)
Unit 1
* Isolation valves for non-safety related portions of ICW system
* Isolates OBHX & TCW HX’s
* CW Pump lube water not isolated. Flow reduced by an orifice. Accounted for in SIAS analysis if line breaks.
* Auto close on SIAS
* Valves can be re-opened after a SIAS by placing the control switch to CLOSE, then OPEN after 30-40 second time delay.
Accomplished in Appendix P of EOP-99
Unit 2
* Isolation valves for non-safety related portions of ICW system
* Isolates OBHX & TCW HX’s and CW Pump Lube Water
* Auto close on SIAS
* Valves can be re-opened after a SIAS by placing the control switch to CLOSE, then OPEN after 65 second time delay.
Accomplished in Appendix P of EOP-99
Discuss Ultimate Heat Sink (UHS) Barrier Valves.
- 2 - 100% Air operated valves
- Valves fail open on loss of air or DC power
- Control Switches in each control room RTGB 102 / 202 – either switch will open both valves
Discuss ICW to CCW Heat Exchangers.
- ICW Flow - 8,500 gpm normal
- ICW Flow – 18,500 gpm MAX
- TCV-14-4A & B: Minimum flow close stop set at 8% flow to prevent water hammer and minimize valve cavitiation
Discuss ICW to TCW Heat Exchangers.
- ICW Flow – 6,250 gpm
- TCV-13-2A & B
- Isolated on SIAS by MV-21-3 & 2
