This contract covers the OSA type support to a nuclear plant in Ukraine, in the framework of the TACIS project system. However, this project had a special character due to the fact that the recently completed Unit 4 went critical in September 2004, during the contract implementation. Therefore the project represents the first-of-a-kind OSA project to a WWER plant during commissioning. It covered the years 2004 (partially) – 2005.
The Contractor provided assistance to the Plant Staff organisation assessing the implementation of the safety related measures (modernisation, completion, rehabilitation) at Rovno 4. The following specific objectives were declared:
To check the actual implementation of the safety improvement measures through relevant technical solutions intended to solve or lower the priority of the issue at least from IAEA ranking level III to level I.
To verify the issues related to rehabilitation and completion of both units have been properly addressed.
A methodology was developed for the assessment of the safety related measures.
15 safety related measures were selected for review (Task 1a) among the “most urgent safety measures implemented at Rovno”. Their review was carried out and the results agreed with Energoatom.
The safety modernisation measures (43), as categorised by the Riskaudit, were assessed by the contractor (Task 1B), on the basis of the methodology developed in the first step. The measures were grouped into packages. For each package the relevant design documentation was gathered and translated into English. The analysis of the implementation of the safety measures was then shared between the contractors (EDF, Skoda, Framatome and Fortum) and the assessment was carried out through a safety review mission. Energoatom was deeply involved in the safety review and approved the conclusions.
The good implementation of the Rovno 4 completion and rehabilitation measures was assessed (Task 2A) in relation to their effect on the safety related equipment.
The measures addressed by Task 1A were the following:
- Embrittlement surveillance program
- High energy pipe breaks
- Fire safety analysis (including cable compartments)
- Cable coating
- Fire detection system
- Fire doors
- Fire damping valves
- Fire resistance of the turbine hall structure
- Smoke prevention system
- Fire suppression in the I&C rooms with automatic gas fire fighting systems
- Insulation materials
- Analysis of the welds on the main steam line and feedwater
- ECCS passive accumulator – preheating issues
- Replacement of the inverter for the emergency supply
- Capacity of the batteries.
The 43 measures addressed by Task 1B were in the following fields:
- Plant balance
- Operational safety
- Equipment testing and qualification
- Commissioning tests
- Electrical equipment
- Building stability
- Core neutronics
- Radiation embrittlement
- Mechanical systems.
In conclusion, the assessment covered 75 measures of the Riskaudit list altogether, while 66 modernisation measures were not covered (either because not safety related, or because not completed, etc.). The final technical report (Task 2B) concluded that 94% of the proposed measures were either acceptable or partially acceptable, and 6% could not been assessed because of their partial implementation at the time of the review.
(quality of the results, lesson learned, recommendations for follow-up)
The review of the modernisation programme for Rovno 4 was implemented successfully. The co-operation between the Tacis OSA Team and the plant experts involved in all the programmed activities was very good, existing a mutual and permanent understanding of the importance of the programme review and assessment.
Further information on the project results could be sought from the beneficiary organizations.
The Project Final report is available at the JRC-IE archive.