The project scope includes studies for different accident phenomena during the emergency cool down process using Symptom Based Emergency Operating Procedures (SB EOPs) for Kozloduy NPP Units 5 & 6.
The project has been implemented in accordance with the ToR (Terms of Reference) requirements and the progression of boron dilution accidents has been analyzed consecutively using Thermal-hydraulic (TH) codes, Computational Fluid Dynamics (CFD) code, Neutron kinetic code and Thermal-mechanical code. For the basic TH calculation, the Relap\SCADAPSIM\ R3.4 code has been used. For the neutron kinetics behavior, the coupled TRACE+PARCS codes have been used. For the thermal-mechanical behavior of nuclear fuel assemblies, the “Transuranus” code has been used.
In the scope of the working program, the following activities are included:
- Preparation of detailed technical methodology for the project regarding the IAEA Guidelines;
- Data collection for reactor operation at full power regarding the project scope modeling activities;
- Development of engineering handbooks for the computer codes: ANSYS 14 (FLUENT), TRACE V 5.0, PARCS 2.7, TRANSURANUS;
- Detailed calculations of the accident progression trough all emergency cool down procedure using SB EOP till safety cool shutdown condition has been reached;
- Preparation of a report with all safety related issues and proposals for safety upgrading.
The results of the analyses are provided in the scope and with the format required by SAR, Chapter 15: "Design basis accidents safety assessment".