In 1993 Fortum Engineering and the nuclear plant at Kola began to co-operate in developing a simulator.

The first application was analysis of primary-to-secondary leakage accidents. The next step was the plant analyser project, which was completed in January 1995. Since then, Kola staff have been using the plant analyser in applications such as process and automation design, safety analysis and the development of the emergency operating procedures. In the latest co-operation between Fortum Engineering and Kola, a training simulator for Kola 1 and 2 has been under development since 1995.

The training simulator and the plant analyser are both based on the multifunctional process simulation software APROS.

APROS (Advanced PROcess Simulator) was developed in 1986 by Fortum Engineering (then IVO Power Engineering) and the Technical Research Centre of Finland. APROS is used for engineering, safety analyses and training simulator applications in nuclear and thermal plants.

The APROS nuclear power plant library has comprehensive simulation models. The thermal hydraulic library contains three, five and six-equation models for calculating one-dimensional two-phase flow. To compute water and steam material properties, fast access material property tables are used. The component model library includes:

• One and three dimensional reactors.

• Pressuriser.

• Steam generator.

• Turbine plant components.

• Feedwater and condenser components.

• Auxiliary system components.

• Containment.

• Control and interlocking systems.

• Electrical system components.

Features available for nuclear plant applications include:

• Accurate physical dynamic models.

• Fast-running simulation.

• Extensive validation.

• Graphical interactive interface for process modelling.

• Modelling of I&C and electrical systems.

• The plant analyser or engineering simulators can be extended to the training simulator.

APROS power plant models range from cold start-up procedures to normal operating modes, normal and emergency shut-downs, load rejections and other disturbances as well as to failures of any combination of process, automation or electrical components.

The APROS simulation software is aimed at users who want to build engineering or training simulators and their plant simulation models by themselves. It can be run on off-the-shelf hardware including Compaq, HP, SUN and SGI workstations. A version running in Windows NT is now available.


The Kola training simulator for units 1 and 2 includes the systems needed for normal operation and accident conditions. It has displays for the operators and for the instructor, who is able to generate any type of malfunction at the simulated plant. It also has versatile functions to analyse and repeat exercises. The trainees can see the same parameters displayed and control the same equipment as in the plant control room.

The primary circuit thermal hydraulics, including the steam generators, have been described using the five-equation model. The secondary circuit and the auxiliary systems of the primary circuit have been described using the three-equation model. In modelling the control, interlocking, protection and electrical systems, the comprehensive APROS libraries have been used and the systems carefully tuned.

There are around 7500 control room input/output signals in the training simulator, around 4500 measurement signals and around 3000 control signals.

The control rooms at Kola are conventional. The training simulator displays resemble the control room and are equipped with the corresponding component symbols. Special displays have been designed for the field operators.

All the training simulator operations are done using the mouse and the keyboard.

The operators’ station displays were specified by the staff at Kola, and are based on the Picasso-3 User Interface Management System. Around 50 displays are available, and all are signed in Russian.

The instructor’s station is used to control the simulator operation and to supervise training. The graphical user interface of the instructor station is simple, with text in Russian.


The training simulator was tested very extensively in close co-operation between the specialists of Fortum Engineering and Kola. At the start of the test period, the Kola staff paid numerous visits to Finland to test the simulator; between these periods Finnish staff corrected the errors that had been observed. Testing was continued after the simulator hardware was transported to Kola in 1998.

The training simulator passed official acceptance tests in August 1999. The full set of acceptance tests covered the simulation of different steady-state operations, start-up and shut-down, and 40 failure and accident situations. The price of the simulator was around $800 000.

The acceptance tests showed that the training simulator is ready for operator training at Kola 1 and 2. During the final acceptance tests the existing simulator training programs were successfully demonstrated. The preparation of the new training programs is important, and this development work will be continued.

Further development will be needed in the near future. The users of the Kola simulator have expressed a need for new monitors for the instructor and operators. Technically, the extension is easy to make, and when the new hardware can be financed the extension will be carried out.

As Kola is upgraded it will be important to continue upgrading the training simulator to correspond with the modernised plant. The first task in upgrading the simulator will be to incorporate the new reactor power control system.

APROS allows the end user independently to upgrade the simulation models. In the future, with appropriate training, the Kola staff will be able to make the modifications independently of the Finnish side.