EFIC Flashcards
What are the power supplies for EFIC Channels?
RS-1/2/3/4 respectively
What are the Train and Channel functions of EFIC?
Train (A & B)- Perform actuation calculation and actuate protection functions (trip) and perform controlling functions (control).
Channel (A - D, C and D channel only) - Monitor parameters (bistables), determine protective function that’s needed and send signal to trip modules (initiate), and provide isolation to faulted generator (Vector).
What is the design basis for EFIC System?
Protect against the consequences of a simultaneous blowdown of both steam generators.
What conditions will actuate EFIC system?
1) OTSG level < 11” for 9.9 sec
2) OTSG pressure < 600 psig
3) Loss both MFPs > 7%
4) Loss all RCPs
5) AMSAC (< 15% FW flow and power > 45%) (Channels A and D)
6) ESAS Actuation (A - ES ch 3/B - ES ch 4)
What is the EFIC trip logic?
What is actuated by MSLI and which trains actuate which components?
What function does the compensation module provide?
Generates the full range level signal by providing a low and high range level signal for each SG.
Also provides the output for OTSG pressure and calculates DP between steam generators for vector signal.
2 modules per cabinet (1 for each SG)
Provides channel function only
How is the low and high range level generated, how do they transition and what are their ranges?
Low range - 6 - 156”
High range - 102 - 500”
As level rises, at 140” output will switch to the high range for full range control. May get oscillation in SG level when swapping due to range of the instrument.
As level lowers, at 115.75” output will swap to low range.
What functions do the bistable modules provide?
3 level functions:
- Initiate (EFW actuation at 11” for 9.9 sec)
- Overfill and Overfill reset (NOT USED)
3 pressure functions:
- Initiate (For EFW and MSLI actuation at 600#)
- Bypass permissive (< 725#)
- Differential pressure (Vector)
What functions does the initiate module provide?
Sends appropriate signal from bistable input to respective trip module.
Provides RCP status from RPS to control module for level control with RCPs off.
Provides Channel Maintenance bypass function
Performs S/D bypass function for Low SG pressure actuation of EFW and MSLI and loss of all RCPs actuation of EFW
Performs channel function
Which protective functions are capable of being bypass in the EFIC initiate module?
- Loss of all RCPs (< 10%) - automatic reset
- Low OTSG pressure (< 725#) - automatic reset
Loss both MFPs bypassed in RPS cabinet
ESAS is bypassed within ESAS
AMSAC bypassed within AMSAC
CANNOT BYPASS LOW OTSG LEVEL!
How does the EFIC maintenance bypass function and how is it interlocked with RPS?
Initiate module performs the maintenance bypass function. Only 1 channel can be bypassed at a time (electrical interlock and procedurally controlled).
EFIC channel in bypass has to be bypassed with associated RPS channel. If a different RPS channel is taken to bypass, will kick associated EFIC channel out of bypass.
What are the associated trip modules and what function do they provide?
Performs the logic actuation for trip buses and produces the vector enable signal on full trip.
Provides an actuation “seal in” which requires operator action to reset once initiate signals have cleared.
Train Function
What function does the TIE module provide?
TIE module provides the interface between EFIC and plant equipment. The TIE modules receive input from TRIP module based on trip logic to actuate associated equipment.
What is the function of the Vector Module? Can this function be overridden?
Provides EFW isolation valve open of close signal
Closes the flow control valves or allow the control module signal to the control valve
Vector isolation can be overriden using man/auto PB for isolation valves or toggle switch for flow control valves.
What is the purpose of the vector enable signal and what vector signals are generated from EFIC and valve positions that occur?
A full trip of EFW will cause a vector enable signal to be produced in trip module and transmitted to all four vector modules and all four control modules.
A vector enable signal must be present to remove the open bias for flow control valves and allow the control module to control level. A pump start via HS will not enable valves to control SG level.
What components are fed from associated EFIC cabinets?
What are the RPS inputs to EFIC?
Describe EFW fill rate limitations?
Fill rate is limited when natural circulation is in effect to prevent overcooling the RCS. The variable setpoint is generated by adding 12” to the actual OTSG full range level signal.
Equation for calculating fill rate is
(6/250 * (SG pressure - 800)) + 2
Describe the remote switch matrix and indications.
