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Support for SNRCU to its evaluation of Safety Analysis Reports of operating VVER 1000

Support for SNRCU to its evaluation of Safety Analysis Reports of operating VVER 1000


UK/TS/29 was a technical support project in which the nuclear safety authority of Ukraine (SNRCU) was supported in reviewing safety documentation, mainly related to Khmelnitsky 2 and Rovno 4 (K2R4).

Task 1 Assistance to SNRCU in evaluation of the plant Safety Analysis Report (SAR) of VVER 1000 (K2 & R4)

Several aspects were reviewed:

  • Accident analysis: the validation of numerical codes used for the accident analysis was reviewed. The experts concluded that the thermohydraulic code RELAP is suitable for VVER accident analysis and neutronic kinetics code DYN3D has a good validation matrix on VVER type reactors.
  • PSA: Experts recommended considering all upgrading measures which were implemented in K2 and R4 in the Probabilistic Safety Analysis (PSA).
  • The review of chapters of the K2R4 Safety Analysis Report (SAR) related to primary circuit and related systems, radioactive waste management, radiation protection has raised a lot of findings that are mainly related to:

o missing information,
o inadequate presentation,
o lack of compliance with requirements for Ukrainian SAR contents,
o the report structure according to international recommendations.

  • The experts recommended to include a chapter on human factors and man-machine interface

Task 2 – Assistance to SNRCU in evaluation of the licensing documents for units commissioning
Several aspects were analysed, which led to the following conclusions:

  • The Emergency plan for personnel protection in case of an accident at the NPP is developed following the IAEA standards with suggestions for improvements.
  • The set of physical start-up tests corresponds to the VVER standard and the experts had no doubt that they are sufficient.
  • Riskaudit recommended limiting relying on test results from one reactor for the other reactor.
  • Operational procedures for the reactor: The procedures were upgraded following the review.
  • Technical specifications: Experts reported that all recommendations for correction and improvement were implemented
  • Procedure for on-site radiation monitoring,: In Ukraine the operators of the NPPs are all alone responsible for the radiation monitoring. Verification by external organisations or the responsible authorities like in France or Germany is not carried out.
  • EOP for reactor: The proposes Emergency Operating Procedures (EOP's) were event based and should be symptom based
  • Guidelines for BDBA management: The experts recommended SNRCU to return the "Beyond Design-Basis Accident Management Guide for Rivne NPP Unit 4" for revision.
  • Programme for units commissioning: Improvements were recommended
  • Pre-commissioning programme: Improvements were recommended

Task 3 – Assistance to SNRCU in the evaluation of conformity of the equipment and construction installed since long period of time

This is a follow-up on Task 4 of UK/TS/27. Improvements in aging management and justifications were recommended.

Task 4 – Assistance to SNRCU in the licensing of measures indicated in the Modernization Programme

IRSN/RISKAUDIT has compared the approach used for the Ukrainian NPP’s of Khmelnitsky 2 and Rovno 4 with the French “superpipe concept”. The solidity substantiation of the implemented pipeline fasteners to sustain the loads resulting from the application of the French super pipe concept is not achieved.
The Report "Analysis of Aircraft Crash Probability for Khmelnitsky-2" in general complies with fundamental safety principles and criteria and with good western practice, but the results of this report can not be used for the NPP Rovno.

Task 5 – Assistance to SNRCU in the review of the DBA analysis and of PSA presented in the SAR of Zaporozhye 5

Selected parts of the "Design Basis Accidents” (DBA) appendix of the ZNPP-5 SAR, specifically related to the the increase of heat removal by the secondary side and a decrease of coolant flow rate through the reactor were analysed.

The experts found that major IAEA recommendations and national regulations are taken into account.

EU experts reviewed the SSTC assessment of the PSA appendix to the SAR of ZNPP-5 and found that it followed the international practice.

General Information

Support for SNRCU to its evaluation of Safety Analysis Reports of operating VVER 1000
€ 1.752.530,08
Budget year: 
Types of activities: 
Technical Support Organisations
RA - Regulatory Authorities
Duration (months): 
Contracting authority: 
European Commission
Partner (Beneficiary): 
State Nuclear Regulatory Committee of Ukraine (SNRCU)
CRIS number: 
Project reference: 
U3.02/02 (UK/TS/29)
Decision number: 
Method of procurement: 
Direct Agreement
Signature date: 
Effective contract date: 
Contract end date: 
Closure date: