EMERSONWestinghouse Nuclear Automation

ADFCS

– Design Overview Design Overview

● Proven Control Application (cont’d)

– F d d d d i l l t d f ti f Fee

d pump spee

d

deman

d is calcula

t

e

d as a 

function o

f

feed water flow demand 

Provide adequate pump head to ensure flow to the 

steam generators is maintained during transients

Coordinated automatic control of steam driven feed 

pp g um

ps when inte

grated into ADFCS 

ADFCS

– Design Overview Design Overview

● Proven Control Application (cont’d)

– S it h t M l d i t l ith S

wit

c

h

to 

Manual mo

de in new sys

tem only occurs with

complete Narrow Range Level failure; otherwise system 

remains in Automatic for all other failures

Steam or feedwater flow input failure; system reverts Steam or feedwater flow input failure; system reverts

to single element control with a reduced steam 

generator narrow range level error input to the flow 

controller PID. controller PID.

Steam pressure, feedwater temperature and 

feedwater header pressure input failures; system 

uses a constant value of the signal that is 

representative of the signal prior to the failure

Advanced Digital Feed Water Advanced Digital Feed Water

● Benefits

– Proven 3rd Generation Design used on Westinghouse and CE plants, deployed 

in eleven units with two additional in next two years; common design with 

AP1000

– Standardized proven and enhanced control logic used for highly reliable Standardized, proven and enhanced control logic used for highly reliable

operational performance allowing operational maneuvers with no level deviation

– Auto control over full power range (1-100%), heatup/cooldown (optional)

– Auto, seamless transition between main/bypass feed water regulation valves 

– Bumpless transition from Automatic mode to Manual mode and back

– Allows Integrated governor control and protection of main feed water pump 

speed

– Plant

-specific dynamic analysis per SWIL addresses plant components & specific dynamic analysis per SWIL addresses plant components

&

operational conditions 

– Supports transient capability with reduced risk of reactor trip

– Minimized field tunin

g and risk of dela

ys at startup

Advanced Digital Feed Water Advanced Digital Feed Water

 Benefits (cont)

– Integrated governor control and protection of Integrated governor control and protection of

main feed water pump speed governor 

– Operational maneuvers with no narrow range 

level deviation

– Output redundancy to control valves 

available that provides additional layer of 

protection against SPV and loss of 

red d t t ll dun

dant controllers

– SLIM hard interface operates seamlessly 

with Soft Control Interface graphics

– A tomatics s itch to man al and alternate A

utomatics

s

witch to man

ual and alternate

actions

– SONG’s and Almaraz have tripped a feed 

pump at power and stayed on line

Almaraz Feed Pump 

Turbine

41

pump at power and stayed on line