Background

Bilateral cooperation between Russia and Germany had included tests of Safety Analysis and Information System (SAIS) procedures at Kola NPP. Since there was a general interest of VVER NPP operating community to improve data collection, processing and safety evaluation of their plants, it was concluded that it was necessary to continue the project, and this would be done in the framework of the TACIS programme. The preceding project included development and application of computer tools which were tested at two other NPP (NPP Brokdorf – German NPP, NPP Greifswald – VVER-440/ V213), and it formed the necessary preconditions for this project.

Existing PSA (started within a preceding project) at Kola NPP used Kola NPP software (plant specific event data base, PC based collection of safety relevant design information) as well as fault tree and event tree US software (IRRAS). The model was used as the basis for Living PSA.

Objectives

This project addressed the operational safety of Russian VVER-440/ V213 NPP by implementing Living PSA at Kola NPP.

The main objectives of the project were:

-Improvement of operational safety of KOLA NPP, based on sophisticated safety evaluation using hard and software as well as modern German know-how on plant operational safety
-Improvement of evaluation, understanding and monitoring of safety features of Kola NPP
-Improvement of operational test, maintenance and emergency procedures as well as the safety documentation used at Kola NPP

Project Results

The situation was discussed during an inception meeting which took place on July 8, 1997, at Kola NPP, and the main project activities/ tasks had been shared between the project participants. KOLA NPP – PSA was responsible for the work performance of not-allocated work. Kurtschatov Institute took care of thermo-hydraulic calculation, frequencies of initiating events, and development and analysis of event trees. Atomenergoprojekt St. Petersburg had as main responsibilities the fault tree development and system analysis, and RISA GmbH was in-charge of reliability data analysis. TUV Nord e.V. was responsible of consultation, support on PSA methods for overall analysis, CCF analysis, human reliability analysis, updating of data bases, and project management.

The activities performed included the following: collection and processing of operational data (between July 1997 and May 1998), safety analysis (between October 1997 and September 1998), recording of safety and operational features into plant software (October 1997 – June 1998), carrying out proposals on improvement of safety of Kola NPP (April 1998 – October 1998), training of the operators on safety features (January 1998 – October 1998), installation of hardware (July 1997 – March 1998), project management (July 1997 – December 1998).

The project had as results:

-plant-specific event and reliability data base according to SAIS structure (applicable to Living PSA)
-generic reliability data base applicable to KOLA NPP plants
-thermal-hydraulic calculations success criteria preconditions for event tree construction
-list of PSA related data interface to plant documentation
-PSA models and results
-list of safety related weak points (based on the assessment of PSA results)
-computer-based data collection on technological design data and safety features (using SAIS format)
-proposals on improvement of safety of KOLA NPP (including safety documentation)

In the frame of the project was organized also the training of operators on safety features, using the documentation of procedures on how operators have been included in the PSA process.

The project started on 1 July 1997 and ended on 26 December 1998 (18 months).