EMERSONWestinghouse Nuclear Automation

– Steam Dump or Steam Bypass – Reactor Pressure Regulation

– Feed System Feed System

– Steam System

– NSSS (core)

● Evaluation response over the full range of operation and 

operational transient conditions

– Normal Operation

– Contingency Operations

● Provides high confidence set of initial tunings

● Pr

ovides

a basis for v

alidati

on 

of desig

n

Feed Water Control Design Overview

- Example

● S/G Model Description Example

– Nodes of S/G Model

Feed Water Control Design Overview Example

Nodes of S/G Model

– Primary side tubes

– Secondary side tube bundle area (inside of wrapper)

– Riser section (from bundle exit through primary separators) Riser section (from bundle exit through primary separators)

– Upper downcomer (generally downcomer area from start of transition cone to top of primary separators)

– Lower downcomer (straight cylindrical portion of downcomer belo transition cone) below transition cone)

– Steam dome (region above top of risers or primary separators)

– Separate mass/energy balances for exit properties

– Momentum balance performed to calculate change in 

various section flow rates

Feed Water Control Design Overview Feed Water Control Design Overview

- Example Example

● Proven Validation Approach

– SWIL (

S

oft

ware In 

Loop) l d l lid ti t ti ) close

d loop valid

ation 

testing 

with plant specific model ensures realistic plant 

operational response

–

ACSL Models validated for various SG’s and now 

Reactor Vessels (BWR)

 Westinghouse

 B&W Canada (5 Units)

 AREVA (5 Units)

 C b ti E i i (4 U it ) Com

bustion 

Eng

ineering (4

U

nits)

 GE BWR 6 Reactor Vessel – Clinton and River Bend

Feed Water Control Design Overview Feed Water Control Design Overview

- Example Example

● Proven Control Application 

– SWIL l d SWIL close

d

-l l oop, real-ti t ti id lid ti time 

testing provides valid

ation, 

allows integration test of graphics, alarms and controls with 

plant operators before system is manufactured

Setpoints verified for operational transients

(determined previously with ACSL control system 

models)

Dynamic set points (Gain, Integral & Derivative) for PID 

are carefully chosen

 For responsiveness to transients For responsiveness to transients

 For near steady state conditions

 Results in no tuning during plant startup

Software In Loop (SWIL) Software In Loop (SWIL)

● Upon completion of setpoint analyses, the ACSL plantspecific control model is switched to Ovation virtual 

controllers for real-time, closed-loop validation testing

● Verifies delivered system contains the proper setpoints and 

control logic as presented in the functional requirement 

documents

● Test performed by Subject Matter Expert along with detailed 

checks of control logic tuning to verify that setpoints match 

the intended design 

Feed Water Application (SWIL) Feed Water Application (SWIL)

● Validation of plant dynamic performance using transient test 

scenariE l os; 

Examples:

– Ramp Load Increase from 1% Power to Turbine Synchronization Power Level at 1%/min

– Turbine Synchronization and Initial Load Pickup

– T bi T i With t R t T i ( t i t l l) Turbine 

Trip Without Reactor 

Trip (at appropriate power level)

– 100% Power ±10% Load Swing

– 100% Power Ramp Load Decrease to 15% Power at 5%/min (bringing on various pumps at the 

appropriate power)

– 1 % 100% %/ ( ff 15

% Power Ramp Load Increase to 100% Power at 5%/min (taking off various pumps at the 

appropriate power level)

– Large Load Rejection (dependent upon plant design typically either 50 or 100% capability)

– Loss of One Feedwater Pump

– Level Setpoint Step at 5% Power

– Level Setpoint Step at 100% Power

– Level Setpoint Step at 50% Power with One Feedwater Pump Operating

– Level Set

point Ste

p at 50% Power with Two Feedwater Pum

ps O

peratin

g.

Feed Water Application Software (SWIL) Feed Water Application Software (SWIL)

● Key Customer representatives participate in testing: 

– Operations, systems engineering, training, etc.

● Results of the testing (trend plots, Control Builder mark-ups, 

and logbook entries) are collected into a test report and 

archived.

● Upon successful completion of this testing, the application 

software is ready for loading into simulator and FAT on 

target plant hardware.

Westinghouse Test Plan Overview Westinghouse Test Plan Overview

● Covers validation test approach.

● Each test phase builds upon previous testing in an Each test phase builds upon previous testing in an

overlapping, structured approach in the order listed below:

1. Initial Software Debug Tests

2. Testing of Application Software (includes dynamic SWIL tests)

3. Simulator Testing

4. FAT 1: Target Hardware (power up, controller/network FAT 1: Target Hardware (power up, controller/network

redundancy failover & I/O checkout)

5. FAT 2: Base System Hardware/software (network, OWS, EWS, 

AVS Domain workstation and system security configurations AVS, Domain workstation and system security configurations

6. FAT 3: Including signal validation, graphics, hardware alarms 

output redundancy and application hardware )

7 Site Testing site acceptance tests and po er ascension test