A1.01/11: Contributions to the Armenian nuclear power plant (ANPP) operator for the implementation of the stress tests at ANPP

Following the Fukushima Daiichi accident, the EU nuclear power plants had to undergo a comprehensive and transparent assessment of their safety and risks ("EU Stress Tests"). Subsequently the EU opened this assessment for voluntary participation of neighbouring countries.

The Armenian Nuclear Safety Authority (ANRA) decided to take part in the exercise and asked the Armenian Nuclear Power Plant (ANPP) to perform the EU Stress Tests using the European Nuclear Safety Regulators Group’s (ENSREG) Specifications.

The objective of this project was to assist ANPP in carrying out the equivalent to the EU Stress Tests.
Another objective was to support ANPP in updating its current Safety Analysis Report (SAR). The updated SAR was to be an improved and consistent report including all newly available information and analyses. It should comply with requirements of the IAEA Safety Guide GS-G-4.1 “Format and Content of the SAR for NPP” (2004) and reflect comments from previous major reviews (OSART, ANRA, ANL, GRS, etc.).

The Terms of Reference of the project has required implementing the project work in seven tasks.

The Task 1 was the general project management.

In the Task 2, the contractor prepared a detailed Stress Test methodology.

The Task 3 consisted in supporting the ANPP in the Stress Tests self-assessment. The contractor established special working groups to review individual chapters of the Stress Test report as prepared by the ANNP. The chapters/working groups included:

• General data of the Site/Plant
• Earthquakes
• Flooding and Extreme Weather Conditions
• Loss of Offsite Power and Loss of Ultimate Heat Sink
• Severe Accident Management

The contractor drafted one information sheet for each chapter. The sheets included main results and conclusions, the proposed actions/recommendations and the required plant safety improvement (when applicable) following the Stress Test assessment.

The output of the Task 3 was “a draft version of the Stress Test report developed by ANPP with a significant support from the contractor consortium and reviewed by the consortium’s project team”.

In the Task 4, the contractor supported ANPP in presenting the draft version of the Stress Test report to ANRA. The presentation took place in a workshop. The Consortium then issued an updated draft Stress Test report taking into account general comments collected in the workshop.

In the Task 5, the contractor supported ANPP in developing a final version of the Stress Test report. ANRA, supported by the Riskaudit Company, reviewed in details the updated draft Stress Test report issuing several sets of comments and questions. The contractor and ANPP then worked together to modify the report and action plan of safety improvements according to the ANRA/Riskaudit comments.
The output of the Task 5 was the final version of the Stress Test (safety self-assessment) report for ANPP. The report follows the Western European Nuclear Regulators' Association (WENRA) format and content used for the Stress Tests at EU nuclear power plants.

In the Task 6, the contractor supported ANPP in modifying its Safety Analysis Report (SAR) according to the IAEA guidelines. The contractor performed a detailed cross-check of the ANPP SAR against the IAEA GS-G-4.1 Safety Guide. The contractor also proposed an “improved structure of Armenian NPP Unit-2 SAR and approach to its update”.

The contractor analysed the current SAR on its content and additional data available. A revised SAR version, meeting requirements of IAEA GS-G-4.1 Guide as much as possible, was proposed. All new available information, documents and analyses were processed and included; new sub-chapters and appendices were elaborated and incorporated into the updated SAR. As a result, the SAR has been extended by more than 800 pages.

In the Task 7, the contractor elaborated the project Final Report.

Conclusions

• According to the Terms of Reference, the Stress Test self-assessment report was supposed to be prepared by ANPP in English, like all national Stress Test reports. During the KoM, the Consortium had to accept the fact that the Report would be in Russian. The contractor Consortium then had to translate the Report versions drafted by ANPP into English. These translations created delays in the review/comment process.
• Because of unavailability of ANPP input data, the Consortium Members had to come in ANPP to collect all the needed and available Input Data themselves. The meetings for collecting the Input Data material added also some delays in the drafting and reviewing process of the Chapters of the Stress Test self-assessment Report.
• Due to the late decision on SAR format (January 2013) and late transfer of last important documents from ANPP, the work on SAR was delayed by 2 months.
• The review process of the Stress Test report was not clearly defined as to the number of iterations between Riskaudit, ANRA, ANPP and the contractor to resolve all questions and comments. Moreover, the questions and answers had to be translated into Russian for ANPP engineers involved. The procedure was only agreed on a coordination meeting of EC, ANPP, Riskaudit and the contractor initiated by the Consortium leader. It allowed completing this task by a date acceptable for the project stakeholders.