AFW Flashcards
(38 cards)
What are the MDAFP Auto Starts?
- Both MFP Trips (in Auto) **
- AMSAC (C-20)
- Load Shed
- Low-Low SG Lvl (2/3) on 1 SG (< 5% U1) (< 22% U2)
- SI
What are the TDAFP Auto Starts?
- Undervolt on the RCP Bus (2/4 RCP busses at 88v)
- SG low low lvl (2/3) on 2 SGs
- AMSAC (C-20)
What are the MDAFP Trips?
- Load Shed
- Overload/Overcurrent
What are the TDAFP Trips?
- Electronic Overspeed (108% at 4698 rpm)
- Mechanical Overspeed (111% 4829 rpm)
What is the purpose of the AFW system?
- Maintain a minimum area of heat transfer in the SGs in order to prevent loss of PW through the Pzr Safety or Relief Valves
- TDAFPs maintain tube sheet coverage of 10 feet
What are the suction sources of the AFW pumps?
- Own CST
- Other Unit CST
- Condensate Hotwells
- ESW
What does the AFW flow conservation signal do?
- Conserves inventory and max flow to the SGs.
What happens on a AFW Flow Conservation signal?
- SG Blowdown Isolations Close
- AFW Pump Test Valves Close
- MDAFP FMOs OPEN (regardless of position)
- seals in for 45 seconds to ensure the FMOs OPEN
What causes a AFW Flow Conservation Signal?
- Anything that starts MDAFW pump auto start
What does the AFW flow retention signal do?
- protect against run-out after steam/feed break ***
What happens on a AFW flow retention?
- Pump discharge valves throttles back
MDAFP - 575 gpm
TDAFP - 955(975) gpm
Which AFW signal overrides the other? (Retention or Conservation)
- Flow Retention overrides Flow Conservation
How will the Unit 1 TDAFP FMOs to SG respond on an auto start signal of a TDAFP?
- U1 TDAFP FMOs will not move from their throttled position
How will the Unit 2 TDAFP FMOs to SG respond on an auto start signal of a TDAFP?
- U2 TDAFP FMOs will full open if they are closed
HOWEVER - They will not reposition if they are already throttled on when an auto start signal is received*
What is the trip and throttle valve powered by?
- N-Train
Where does the back up water supply to the suction of the MDAFPs come from?
- East ESW Header
Where does the back up water supply to the suction of the TDADPs come from?
- West ESW Header
What will cause an AMSAC Signal?
- FW Flow < 25% (3/4 feed flows)
Opening 1-FW-129 feeds what header from which pump?
- Feeds U1 2/3 SGs (East) from the U2 W MDADP
WHat is the T.S. Minimum for the CST and what does it provide?
- 182,000 Gal
- Maintain the plant in Mode 3 for 9 hours with steam discharge to the atmosphere via PORVS with LOOP.
- OR-
- Capability of holding the Unit in MODE 3 for 2 hours followed by a 4 hour cooldown to RHR
Which SG(s) provide steam the TDAFPs?
- 2 and 3 SGs
Are the AFW flow retention switches powered from N train?
- NO
- ELSC buss (Train B)
- AFW buss (Train A)
What does T.S. 3.7.5D (AFW System) state?
- If 3 AFW trains inoperable in Modes 1-3 (Mode 4 when relied upon for heat removal)
IMMEDIATELY - Initiate action to restore 1 AFW train to Operable status LCO 3.0.3 and other mode changes are suspended until 1 AFW train is restore to Operable status
What does T.S. 3.8.4D (AFW System) state?
- If Train N DC electrical power system inoperable in Modes 1-4
IMMEDIATELY - Declare the TDAFW pump inoperable
