The training and technical knowledge of reactor operators about the behaviour of their plant is a key element to improving the operational safety of that plant. It is widely recognised that simulators play an extremely important role in establishing viable training programmes for nuclear power plants.

Full-scope and analytical simulators provide such training tools for reactor operators. Both types of simulators require the same scope from the simulation models. A full-scope simulator provides control panels that replicate the actual control room panels as the interface between the operators and the simulation computer. Analytical simulators use personal computers as the interface between the operator and the simulation computer. These tools are used to train the reactor operators in normal and off-normal operations and in responding to emergency and accident situations.

Following the Chernobyl accident, the US, in co-ordination with other Western countries, began and continues to supply training, equipment, and simulators to Russia and Ukraine. As a part of its work to improve the safety of Soviet-designed nuclear power plants, the US Department of Energy (DOE) is developing and providing simulators for many of the Russian and Ukrainian nuclear power plants. These simulator projects are managed by the Pacific Northwest National Laboratory (PNNL), which provides management and technical support to the DOE, with Brookhaven National Laboratory (BNL) providing technical support to PNNL and the DOE. One of the projects under this programme was to develop a full-scope simulator for the Kola 4.

KOLA 4

Kola 4, in the Murmansk region of Russia, is a second generation VVER-440 (V-213). It has a nominal rated capacity of 440MWe and 1375MWt.

Kola has six primary coolant loops and six corresponding horizontal steam generators. It does not have the typical containment of PWRs and the VVER-1000s. However, it does have a “bubbler/condenser” tower connected to various accident localisation compartments within the reactor building to mitigate the effects of severe accidents. The V-213 also has an emergency core cooling system (ECCS).

ROLES OF THE PARTNERS

A Memorandum of Understanding (MOU) to develop the full-scope simulator for Kola 4 was signed by the US and Russian partners on 19 July, 1995. Under this MOU, the US side agreed to provide funding for the simulator hardware – comprising all computer, control panel, and power equipment – and to provide training to the Kola operators. The Russian side, on the other hand, agreed to fund simulator software development, integration of all hardware and software, installation, and testing of the simulator. The Russian side also provided the facility to house the simulator.

SIMULATOR DEVELOPMENT

The Russian Institute for Nuclear Power Plant Operations (VNIIAES) and General Energy Technologies (GET) – which is located in Moscow at the facilities of VNIIAES – were the prime contractors for the Kola 4 project. GSE Power Systems of Columbia, MD, a leading simulator vendor, supplied all the computer equipment for the simulator. The US funded contracts were with GSE and GET, and the Russian funded contracts were with VNIIAES. The US supplied the following hardware via contracts with GSE and GET:

• Simulation computer (SGI Challenge L R8000 with 4x90MHz CPUs).

• Instructor station computer and workstations (four SGI Indigo R4400).

• Pentium PCs.

• Control panels including all instruments and devices.

• Input/output (I/O) system (interface between the simulation computer and the control panel).

• Power distribution centre.

• Uninterruptible power supply.

• Control room communication and sound system.

• Audio/video system to record and replay training sessions.

Electropult, located in St Petersburg, manufactured the control panels. The input/output system was also manufactured in Russia in accordance with VNIIAES’s Unicon design specification. The simulator software model was developed to satisfy the US’s ANSI/ ANS-3.5-1985 standard. Thus, as specified in this standard, the simulator can simulate normal plant evolutions (steady state and transients) and plant malfunctions specific to the VVER design. The simulated systems include the primary system, main steam, balance of plant, reactor core neutronics, turbine thermal-hydraulics, turbine and reactor control system, and logic systems.

During the project, GET trained the Kola staff in the operation, maintenance and modification of the simulator. The training included courses in simulator instructor training, computer hardware and software training, and I/O system hardware maintenance training. Brookhaven National Laboratory and GET also provided training to the Kola staff in verification and validation procedures for full-scope nuclear plant simulators. The latter training was helpful to the staff during their participation in acceptance tests of the simulator.

The assembly and integration of all hardware and software into a functioning full-scope simulator was carried out at VNIIAES’ facilities in Moscow. Acceptance test procedures were developed by VNIIAES and approved by Kola. A programme of factory acceptance tests was conducted at VNIIAES. Following successful completion of these tests, the simulator was shipped to Kola. Upon arrival at site, the simulator was reassembled and tested. These site acceptance tests were successfully completed, and the simulator formally turned over to the Kola plant in April 2000.

SIMULATOR OPERATION

A full-scope simulator for Kola 4 was developed and delivered to the Kola Training Centre. It was installed, tested and accepted for training by the Kola plant. It was inevitable that there were delays in the work carried out by VNIIAES. Nevertheless, the Kola plant was able to meet all of its obligations for this simulator project and members of the Kola training centre staff were active participants. As a result, in spite of the delays encountered, the project proceeded smoothly.

To help the plant use the simulator for training soon after its development, the US partners provided funding to develop 20 simulator exercise guides (SEGs). These provide a structured set of steps, notes, and instructions for the simulator instructors, and help them prepare and carry out simulator training sessions. The SEGs were developed by GET. The training centre has begun to use this simulator as an integrated part of its training programme. It is expected that access to this full-scope simulator will provide the following benefits:

• Improved staff training in normal and off-normal operations, and during accident and emergency scenarios.

• Improved reactor operators’ understanding of the overall and system-level plant operating characteristics.

• Development and validation of emergency operating instructions.

• Development and implementation of training programmes based on simulators.