PWR Simulator
PRESSURIZED WATER REACTOR WITH
PASSIVE
SYSTEM
The purpose of the 600 MW(e) advanced PWR reactor NPP
simulator is educational — to provide a training tool for university
professors and engineers involved in teaching topics related to the advanced
passive PWR reactor. Nuclear engineers, scientists and trainers
familiar with the conventional PWR would
find this simulator useful in broadening their understanding of the advanced
PWR characteristics,
transients, power plant dynamics, and passive safety features. As such, this
simulator is currently used in the IAEA Workshop "NPP Simulators for
Education".
The simulator has sufficient
simulation fidelity to provide realistic PWR plant responses during normal operations and
accident situations. More importantly, Mode K Reactor Control Strategy
is simulated in details, which allows double closed loop control of (1)
reactor coolant temp (2) axial power difference, with the use of:
- Heavy-worth control rods bank dedicated to axial shape control.
- Light-worth control rods bank for controlling coolant temp at
setpoint.
- Auto regulation of both the reactivity and power distribution -
permits load-follow operations (frequency control) to respond to grid
conditions, with minimum use of Boron.
The PWR simulator also has a user-machine interface that mimics the
actual control panel instrumentation. More importantly,
it allows user’s interactions with the simulator during
the operation of the simulated PWR plant.
The current configuration of the Simulator is able to respond to the
operating conditions normally encountered in power plant operations, as well
as to many malfunctions, as summarized in the following Table.
|
System |
Simulation Scope |
Display Pages |
Operator Controls |
Malfunctions |
|
REACTOR
CORE |
*
Neutron flux levels over a range of 0.001 to 110% full power, 6
delayed neutron groups * Decay heat (3 groups)
* All reactivity control devices - “dark” rods; “gray” rods;
boron control.
* Xenon/Iodine poison
* Reactor power control system
* Reactor shutdown system
|
PWR Reactor Power control
PWR Control Rods & SD rods
PWR Trip parameters
|
* Reactor power and rate of change (input to control
computer)
* Manual control of reactivity devices - control rods and boron
addition/removal
* Reactor trip
* Reactor setback
* Reactor stepback |
* Reactor setback and stepback fail
* One bank of Dark control rods drop into the reactor core
|
|
REACTOR COOLANT |
* Main circuit coolant loop with four pumps, two steam
generators, four equivalent “lumped” reactor coolant channels
* Pressure and inventory control which includes pressurizer,
coolant letdown condenser, charge & letdown control, and pressure
relief
* Operating range is from zero power hot to full power |
PWR reactor coolant system
PWR coolant inventory & pressurizer
PWR inventory control
PWR pressure control
|
* Reactor coolant pumps * Coolant makeup pumps
* Pressurizer pressure control: heaters; spray; pressure
relief valve
* Pressurizer level control by regulating coolant feed & bleed
flow
* Isolation valves for: coolant feed and bleed |
* Pressurizer pressure relief valve fails open *
Charging (feed) valve fails open
* Letdown (bleed) valve fails open
* Pressurizer heaters #2 to # 6 turned "ON" by malfunction
* Reactor header break
|
|
STEAM & FEED-WATER |
* Boiler dynamics, including shrink and swell effects *
Steam supply to turbine and reheater
* Turbine by-pass to condenser
* Extraction steam to feed heating
* Steam generator pressure control
* Steam generator level control
* Boiler feed system |
PWR Feedwater and Extraction Steam |
* Feed pump on/off operation
* Boiler level controller mode: Auto or manual
* level control setpoint changes during Auto operation
* Level control valve opening during manual operation
* Extraction steam valves opening
|
* All level control isolation valves fail closed
* One level control valve fails open
* One level control valve fails closed
* Main feedwater pump trips
* All main steam safety relief valves open
* Steam header break
* Steam flow transmitter failure
|
|
TURBINE-GENERATOR |
* Simple turbine model * Mechanical power and generator
output are proportional to steam flow
* Speeder gear and governor valve allow synchronized and
non-synchronized operation
*Turbine steam bypass |
PWR Turbine-Generator |
* Turbine trip
* Turbine run-back
* Turbine run-up and synchronization
* Condenser steam discharge valves |
* Turbine spurious trip
*Condenser steam discharge valves failed closed
Turbine Runback |
|
OVERALL UNIT |
* Fully dynamic interaction between all simulated systems
* Overall unit power control with reactor leading mode; or
turbine leading mode
* Unit annunciation & time trends
* Computer control of all major system functions |
PWR Plant Overview
PWR Control Loops
PWR MW Demand SP & SGPC |
* Reactor power setpoint and rate entry in reactor-lead
mode.
* Turbine load setpoint (MW) and loading rate entry in
turbine-lead mode |
|
|
SAFETY SYSTEM |
* Emergency Core Cooling System (ECC) * Simple Model for
containment. |
PWR Passive Core Cooling |
|
Reactor inlet header break |
The interaction between the user and the simulator is via a combination of
monitor displays, mouse and keyboard. Parameter monitoring and plant operator
controls, implemented via the plant display system at the generating station
,are represented in a virtually identical manner on the simulator. Control panel
instruments and control devices, such as push-buttons and hand-switches, are
shown as stylized pictures, and are operated via special pop-up menus and dialog
boxes in response to user inputs.
Below are samples of the PWR Simulator screens:
PWR Overview Screen
PWR Control Rods and Shutdown Rods Screen
Advanced PWR Power Control Screen
PWR Coolant Inventory & Pressurizer Screen
PWR Passive System Screen
|
CTI SIMULATION
INTERNATIONAL
