TS-G

(Training Simulator for Garoña Nuclear Power Plant)

Department of Applied Mathematics and Computer Science

University of Cantabria

DESCRIPTION

TS-G (Training Simulator for Garoña plant) is an interactive graphic representation system which enables all kinds of accidents and operator actions to be simulated in real time. TS-G is a tool which, because of its interactivity characteristics, is particularly suitable for the training of plant operators, teaching of new staff and analysis of accidents occurred, although it can also be used for other purposes. The Dataviews graphic interface design software with an adapted version of the MAAP simulation code has been used in the development of the system.

This simulator has been designed for general use, although it has been customised to fit the parameters and characteristics of the current layout of The Santa Maria de Garoña Nuclear Power Plant.

BACKGROUND

TS-G was initiated as part of a Research and Development project jointly undertaken the Department of Applied Mathematics and Computer Science of The University of Cantabria and Nuclenor S.A.. This project´s aims are to study, analyse and develop information science techniques for the control and simulation of the systems which make up a Nuclear Power Plant, particularly in the fields of Neutronics and Thermohydraulics, with specific application to The Santa Maria de Garoña Nuclear Power Plant.

It was necessary, therefore, to provide an analytic tool capable of simulating malfunctions which affect the running of a nuclear power plant, as well as probable temporary adjustments and hypothetical accident sequences. This tool was to have several important applications in the running and the security of the power plant, as well as in the training of operators.

Since codes capable of simulating the running of a nuclear power plant have long been available, the first stage was to develop a series of applications which, by incorporating graphic capacities, would enable a faster interpretation of the results of the simulations obtained by these codes. These applications were designed in such a way that real plant events could also be studied and even compared with the simulations.

With the experience acquired from these developments, it was decided to commence the development of a training simulator which, whilst maintaining and improving the previously mentioned graphic characteristics, would facilitate an interactive link to the adopted simulation code.

PROJECT AIMS

In order to be sure that the simulation codes truly correspond to reality, it is necessary to constantly evaluate its models by comparing the simulated events with real plant data, which leads to the adjustment of parameters.

The initial aim of the project was to compile real and simulated events for risk analysis, the study of systems behaviour and the revision of operating procedures.

These operations, whilst they may be enhanced by interactive simulation, can largely be dealt with by non-interactive applications such as those developed initially.

Another important purpose of the simulation of nuclear power plants is to be found in the area of education, both in teaching and in the training of operators. In order to adequately fulfil this objective,it is essential to dispose of a simulator with an interactive capacity. In this way, the operators can manipulate the controls in a manner similar to that which they would use in the plant , and can thus be trained to respond to any anomalous situation.

To give the TS-G greater flexibility and a greater likeness to the reality of the everyday running of the plant, a user interface was built.

SOFTWARE USED FOR DEVELOPMENT

In order to develop the interface, the Dataviews software was chosen, principally for its orientation towards instrumentation engineering and process control. Moreover, this software uses the graphics standard X-Window and runs under the operating system UNIX.

Furthermore, the machines in which it is installed do not need to be particularly powerful; low priced work-stations and/or high level personal computers are enough.

SIMULATION CODE

In order to choose the most appropriate code to build the interactive simulator, the TRAC (Transient Reactor Analysis Code) and MAAP (Modular Accident Analysis Program) codes were studied in depth. Their structures, modelisation capacities, the variables that they use, accuracy and speed of calculation, the capability for interactive use, etc. were all studied.

As a consequence, it was considered that the MAAP code was the most suitable for the development of the software. It should be pointed out that while the MAAP code offered the best characteristics for use in the simulator, it had to be appropriately adapted in order to function interactively.

THE TRAINING SIMULATOR

The TS screens make up a user environment and, in them, the power plant´s systems are represented by objects whose dynamic properties are associated to the events and variables which determine their performance. At the beginning of each session a routine creates the connections between these properties and the variables and events of the MAAP code, thus making way for interactive communication. The interface also incorporates event control routines allowing the user´s actions to be registered.

The simulator is designed in such a way that several users can interact simultaneously on the process. It consists of six monitors assigned both to control and to visualise systems. The instructor, who is the person in charge of provoking anomalies during the training exercises for operators, disposes of a console from which he can interact in real time. Meanwhile, by means of five other consoles, the operator can undertake control operations, resolving the conflictive situations provoked by the instructor. The main interactive characteristics of the simulator are:

The INSTRUCTOR can initiate malfunctions and/or accidents using his control panel.
The emergency signals are detected on the alarm screen by means of a change of colour and/or sounds.
During the simulation, a detailed description of events can be observed by means of messages which describe the actions of the operator and the responses of the system itself.
The operator can observe and control the status of NPP systems using the mouse.
Using an imported P & ID, the operator has the possibility of interactively changing the status of the components (pumps, valves etc.).
The TS contains the SPDS displays among many others, so the operator uses the same information during training and during the operation. The displays can be customized as needed.
Variables are displayed by means of several types of graphics and/or digits with colour changes.
By means of X-Y graphics values can be identified both inside and outside of admissible regions.

One TS layout, currently in operation, consists of the following hardware: One Hewlett Packard series 9000/712 workstation. Six X11 terminals to visualise different systems, one of them for use as the instructor´s post. One laser printer for printing graphics of the evolution of the desired variables during or at the end of each session.

An additional capacity already incorporated into the simulator is the possibility of visualising the real time plant data by making use of the data acquisition system installed in Santa María de Garoña NPP. This means that the same screens developed for the T.S. have been used saving efforts. This capacity can be achieved from any computer post at NUCLENOR or even the University of Cantabria. In this process, a microwave radiolink is used to overcome the problem of the 140 km. which separate the University of Cantabria from the NPP.

WORK IN PROGRESS

Furthermore, work is already being carried out on the incorporation of an expert system. This expert system will enable real time plant data to be taken and processed in order to generate a MAAP input file. This input file will contain the accident sequence which the expert system has arrived at. The expert system will also contain all the emergency operation procedures (EOP´s) in such a way that the transient evolution reflects the actions that the operator should take.

Comments to Pedro Corcuera: mailto:corcuerp@unican.es