VVER 440 Multifunction Sim. for Armenia

Proper qualification of operations personnel, especially the main control room (MCR) staff, is one of the vital conditions of safe and reliable plant operation. To ensure it, a regular and effective personnel training is necessary. A significant part of any nuclear power plant (NPP) training program is simulator training providing the MCR personnel with the opportunity to practice both routine plant operations and operator’s response to abnormal or accidental situations.

In connection with the long shutdown period of the Armenian (Metsamor) Nuclear Power Plant (ANPP), the personnel training had been substantially reduced. Although some personnel training was provided before and after the plant start with the support of other VVER-440 operating plants and some external organizations, it was necessary to establish a sound training programme based mostly on on-site facilities, including a simulator, allowing the plant personnel to attend training sessions easily and frequently, thus maximising the cost/benefit ratio. One of the most convenient, easy-to-implement and economical options of an on-site simulator was a computer-based multifunctional simulator (MFS).

Based on the previous and successfully implemented PHARE/TACIS projects on supply of 8 multifunctional simulators to other VVER-440 plants in Russia, Ukraine and Slovakia (TACIS R2.04/93, U2.03/93 and PHARE 93/4.1.3 projects commonly known as the “EVVEREST” project), the EVVEREST Consortium (Belgatom, Corys T.E.S.S and Siemens) organized a mission to the Metsamor NPP in April 1997. The aim of the mission, covered by a separate contract 1997/24672 (formerly 97-0188), was to determine, how the MFS could be developed for the ANPP taking advantage of the previous developments performed for the EVVEREST project – see the related dissemination summary. Based on the mission, the EVVEREST Consortium proposed establishment of an EC-funded project on installation of the MFS at the Metsamor NPP. It has been accomplished within the A2.01/96 project.

The main aim of the A2.01/96 project was to develop and supply a multifunctional simulator of the Armenian type of the VVER-440 NPP, which would allow comprehensive on-site training of MCR personnel in managing normal, abnormal (equipment failures or malfunctions) and emergency (leaks or breaks) situations, including plant system performance and background physical phenomena. The MFS option would allow the Metsamor NPP to (1) quickly improve the on-site operator training facilities, (2) upgrade the simulator easily if necessary and (3) possibly extend the MFS into a full-scope simulator in the future.

The most important benefit of the project was expected to be the overall improvement of quality of the plant on-site training and consequent enhancement of plant operational and nuclear safety.

The project work consisted in the following tasks:

• Task 1 – Methodology to collect the data package (collection of data necessary to develop the MFS)
• Task 2 – Procedure development (project organization, Quality Assurance)
• Task 3 – Simulator supply
• Task 4 – Simulator model modification/adaptation
• Task 5 – MFS validation programme
• Task 6 – MFS personnel training (instructor course, maintenance course, on-job training)

The Metsamor MFS development was based on experience gained from MFS supplied to the other VVER-440/V230 plants within the EVVEREST project. As a starting point, the Jaslovske Bohunice 2 and Novovoronezh 3 MFS models were selected, as these units had the closest similarities with the Metsamor NPP design.

The Metsamor power station is basically a VVER-440 plant of the V230 type (the first generation of standardized VVER-440s) having some design modifications to increase its seismic resistance (thus specified as a separate V270 type). The main differences of the V270 type compared to the standard V230 design have included: using V213 plant reactor coolant pumps (sealing-type RCP instead of the sealless RCPs normally used in V230 plant), installation of additional RCP sealing water system and additional high-pressure safety injection system.

The J.Bohunice 2 MFS models were used for modelling Metsamor primary circuit, power output and house power distribution systems including associated auxiliary and I&C systems. The Novovoronezh 3 MFS models were used as a basis for development of Metsamor secondary circuit models (including the main turbine-generator, auxiliaries and related I&C systems).

These initial MFS models were modified and adapted to the actual Metsamor plant design and system configurations. The modifications included process parameters (values, ranges, margins, etc.), simulated equipment failures, initial conditions of the simulated events, man-machine interface, instructor workstations, training utilities and the MFS control computer system itself. Measures have been also taken to enable later extension of modelling functions and changes of hardware configuration of the MFS including its integration into MCR control panels. The MFS equipment models and modes of operation actually corresponded to the Metsamor Unit 2.

The integral part of the MFS development was a comprehensive validation program to verify proper functionality of the MFS during its development and tuning. The validation tests, which took place at the development site, included:

• Stand alone tests of individual models without MMI (checking of individual model performance by use of basic parameters);
• Stand alone tests during integration (checking interface between the individual models, soft panels and instructor workstation, and stability of the models in integrated environment);
• Dynamic integrated tests (checking the simulator dynamic behaviour at simulation of various operational modes, dynamic performance of individual plant systems and interdependent system groups, stabilisation of the simulator after a transient, etc.)
• Pre-acceptance and acceptance tests at the development site (performed by the developers and end user respectively; they included tests of pre-selected operational modes and conditions, transients, malfunctions, as well as functional and reliability tests of simulator computer system, soft panels with interface and instructor’s workstation).

After completing the validation tests, the MFS was disassembled, transported to the plant and installed on site. Later on, on-site tests were performed to verify the same operability of the MFS as at the development site.

Finally, upon completing the MFS development, the MFS instructors were trained in using the simulator; specific training was provided at VUJE Trnava, Slovakia, also on use of symptom-oriented Emergency Operating Procedures. The Metsamor plant IT personnel were trained in simulator maintenance

The project was implemented by the Consortium of Belgatom (leader) and Corys T.E.S.S in accordance with the EC contract 98-0373. The MFS itself was developed at Corys T.E.S.S. site in Grenoble, France. According to the contract, the Armenian NPP multi-functional simulator was considered the 9th “EVVEREST” project.

The contract was awarded to the Consortium in November 1998 with the duration of 20 months. The project kick-off meeting was held in Armenia in January 1999. The further project progress, however, was delayed by four months due to negotiations on involvement of local Armenian subcontractor (Armatom) in the project. Finally, the following organizations were involved in the project implementation: the end user (Metsamor NPP), the above mentioned Consortium and subcontractors (Armatom, Armenia; Simulation System Ltd., Obninsk, Russia; KFKI Budapest, Hungary).

The foreign subcontractors, who were involved also in the previous EVVEREST projects, used their experience and provided support to the local Armenian subcontractor and the end user. In general, the subcontractors were mainly involved in collection of plant operational data, in modifications and customization of existing MFS models, in the model testing and parallel tuning.

The project was successfully completed in November 2000, when the MFS was put in operation. Currently, it is used for initial and refreshment training of all ANPP MCR personnel and is regularly upgraded.

Conclusions

It can be concluded that objectives of the projects have been fully met and that the project has substantially contributed to both personnel training improvement and nuclear safety enhancement at the Metsamor Nuclear Power Plant.