CANDU-9 Simulator

      CANada Deuterium Uranium Reactor Simulator

       

The CANDU-900 MWe Compact Simulator was originally developed to assist Atomic Energy of Canada Limited (AECL) in the design of the plant display system. The specification for the Simulator required that the software be capable of execution on a Personal Computer, to operate essentially in real time, and to have a dynamic response with sufficient fidelity to provide realistic signals to the plant display system. The Simulator also had to have a user-machine interface that mimicked the actual control panel instrumentation, including the plant display system, to a degree that permitted the development and operation of the simulator in a stand-alone mode, i.e. in the absence of the plant display system equipment. These features also made the Simulator suitable as an educational and training tool. Currently the CANDU-9 simulator is used as part of the nuclear engineering program studies at McMaster University, and University of Ontario Institute of Technology (UOIT), both Canadian universities. Other countries having the CANDU reactors, such as Korea, China, and Romania, are also using the simulator in their university programs.

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 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, include photo-neutron groups. Decay heat (3 groups). All reactivity control devices. Xenon and boron poison. Reactor regulating system Reactor shutdown system	Reactivity control devices Shutdown rods Reactor regulating system	* Reactor power and rate of change (input to control computer) * Manual control of reactivity devices * Reactor trip * Reactor setback * Reactor stepback	* Reactor setback and stepback fail   * One bank of control rods drop into the reactor
HEAT TRANSPORT	Two phase main circuit loop with four pumps, four steam generators, four equivalent reactor coolant channels. Pressure and inventory control (pressurizer, degasser condenser, feed & bleed control, pressure relief). Operating range is zero power hot to full power	Main PHT circuit PHT pressure control Pressurizer control Feed and bleed control Inventory control Degasser condenser control	* Ccirculating pumps * Pressurizing pumps * Pressurizer pressure * Pressurizer level * Degas cond. pressure * Degas cond. level * Feed & bleed bias * Isolation valves for: pressurizer, degasser cond., feed and bleed	* Main circuit relief valve fails open *Pressurizer relief valve fails open   *Pressurizer isolation valve fails closed   *feed valve fails open   *Bleed valve fails open   * Reactor header break
STEAM & FEED-WATER	boiler dynamics, including shrink and swell effects Steam supply to turbine and reheater Turbine by-pass to condenser Steam relief to atmosphere Extraction steam to feed heating Steam generator pressure control Steam generator level control Boiler feed system	Steam generator feed pumps Steam generator level control Steam generator level trends Steam generator pressure control Extraction steam	* Level controller mode: computer or manual * Manual level control gain & reset time * Level control valve selection * Level control isolation valve opening * Extraction steam valves * Feed pump operation	* All level control isolation valves fail closed * One level control valve fails open * One level control valve fails closed * All feed pumps trip * All safety valves open * Steam header break * Flow transmitter fails
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-Generator	* Turbine trip * Turbine run-back * Turbine run-up and synchronization * Atmospheric and condenser steam discharge valves	* Turbine spurious trip * Turbine spurious run-back
OVERALL UNIT	Fully dynamic interaction between all simulated systems Unit power regulator Unit annunciation Computer control of all major system functions	Overall Unit Unit power regulator

The simulation uses an object oriented approach: basic models for each type of device and process to be represented are developed in FORTRAN. These basic models are a combination of first order differential equations, logical and algebraic relations. The appropriate parameters and input-output relationships are assigned to each model as demanded by a particular system application.

The interaction between the user and the Simulator is via a combination of monitor displays, mouse and keyboard. Parameter monitoring and 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.

CTI SIMULATION INTERNATIONAL CORP. © 2006