Summary
 
The aim of the project was to assist Bulgarian Nuclear Regulatory Agency (BNRA)in the process of review of the Safety Analysis Review (SAR) for Kozloduy Units 5 and 6. An additional objective was placed on the improvement of BNRA review and assessment capacities through training of Agency staff and transfer of knowledge and capabilities in the area of SAR review with the goal to give BNRA a methodology and procedure of carrying SAR reviews more effectively in the future.
 
The specific tasks that were performed:
 
Reviewing and assessment of the Safety Analysis Reports of Kozloduy NPP Units 5 and 6 against compliance with the international requirements. In the framework of this task, the Consultant assisted BNRA by provision of expertise for the following subtasks:
 
· reviewing the completeness of the information provided by Kozloduy NPP in the Safety Analysis Report and assess its adequacy.
· assessing the adequacy of modelling assumptions and computer codes used in the SAR.
· reviewing and assessing the methodology applied to: (1) "design bases accidents"; (2) "beyond- design basis accidents"; (3) used acceptance criteria; and (4) more in general, to design a modern methodology (guide) for review and assessment of SARs (including the development of structure and format of a regulatory assessment procedure).
· performing assessment of selected and sensitive assumptions and analyses, which require engineering judgement (e.g. review and possible enlargement of the existing list of initiating events to be considered in the SAR).
· To reviewing and confirming the safety demonstration in the SAR in view of the recent implementation of the modernization program based on internationally recognized safety principles, internationally formulated safety guidelines and established practices.
Training and validation of the methodology for review and assessment of SARs.
 
In the framework of this task, the Consultant assisted BNRA by provision of expertise for the following subtasks:

• On-the-job training of BNRA and TSOs staff in review of SARs.
• Validation and assessment of the methodology through its application to specific safety cases concerning the SAR.