Justification of fire protection measures in the NPP control room using CFD fire modeling

Introduction. The present paper provides justification of fire safety measures to protect systems of the main control room of NPP using computational fluid dynamics fire modeling.

Aim. To develop fire protection measures for systems of the NPP control room using computational fluid dynamics model.

Materials and methods. The study involved analysis into purpose and application scope of various methods for modeling dynamics of development and spread of fire hazards. The application of the computational fluid dynamics fire modeling for multifunctional premises was considered.

Results. Following the analysis of different methods for modeling the dynamics of development and spread of fire hazards, the present paper introduces the potential of using various methods of fire modeling in the evaluation of fire hazards for main control room. The obtained computations show that the temperature at the reinforcement site remains below the critical value in the most dangerous fire development scenarios like ventilation controlled fire. Moreover, fire hazards fail to spread through the walls of an uninsulated room within three hours at any value of fire load in main control room.

Conclusions. The study revealed a potential for using computational fluid dynamics fire modeling for evaluating fire hazards in various buildings and premises, as well as for justifying the sufficiency of fire resistance requirements established for building structures. This regularity is obtained under conditions of preventing the spread of fire beyond the fire zone within the estimated burnout time of the entire fire load. The results received for this particular type of premises (cable floor) indicate that the designed fire resistance of the barriers separating safety system premises and normal operation premises guarantees non-proliferation of fire. The obtained regularities can be used in the development/revision of regulatory documents on fire safety at operating NPPs and NPPs under construction.

1. <i>Putsev D.I., Krivtsov Yu.V., Groshev Yu.M., Lobanova N.A.</i> Evaluating feasibility of field modeling of fire to calculate fire characteristics in buildings and premises. Vestnik NIC Stroitel’stvo = Bulletin of Science and Research Center of Construction. 2023;37(2):37–70. (In Russian). https://doi.org/10.37538/2224-9494-2023-2(37)-37-70

2. <i>Putsev D.I., Mishina S.Yu., Groshev Yu.M.</i> Justification of measures aimed at ensuring the required fire resistance of structures enclosing NPP premises using CFD fire modeling. Vestnik NIC Stroitel’stvo = Bulletin of Science and Research Center of Construction. 2024;40(1):49–60. (In Russian). https://doi.org/10.37538/2224-9494-2024-1(40)-49-60

3. Application of the field method of mathematical modeling of indoor fires: Methodological recommendations [internet]. Moscow: VNIIPO; 2003. Available at: https://files.stroyinf.ru/Data2/1/4293808/4293808018.pdf (In Russian).

4. <i>Karpov A.V., Ryzhov A.M.</i> Recommendations for the use of the field method of mathematical modeling of fire. Moscow: VNIIPO; 2002. (In Russian).

5. Recommendations for assessing the fire resistance of systems (elements) important for safety at Russian nuclear power plants. Moscow: VNIIAES; 2000. (In Russian).

6. <i>Molchadsky I.S., Astakhova I.F.</i> Mathematical model of temperature fields of the initial stage of a fire in a room. Fire and Explosion Safety. 1995;4(2):31–33. (In Russian).

7. Verification of a three-dimensional mathematical model for calculating fire dynamics to assess the impact of fire on NPP equipment. Moscow: LLC “STEM”; 2001. (In Russian).

8. State Standard R 12.3.047-2012. Occupational safety standards system. Fire safety of technological processes. General requirements. Methods of control. Moscow: Standartinform Publ.; 2014. (In Russian).

9. <i>Koshmarov Yu.A., Puzach S.V., Andreev V.V., Kozlov Yu.I.</i> Forecasting of fire hazards in the room. Moscow: Academy of GPS of the Ministry of Emergency Situations of Russia; 2012. (In Russian).

10. RD 03-34-2000. Requirements for the composition and content of the report on verification and justification of software tools used to justify the safety of nuclear energy facilities [internet]. Available at: https://www.secnrs.ru/upload/files/rd2000.pdf. (In Russian).

11. NP-001-15. Federal norms and rules in the field of nuclear energy use. General provisions for ensuring the safety of nuclear power plants. Moscow: Federal State Budgetary Institution “Scientific and Technical Center for Nuclear and Radiation Safety”; 2016. (In Russian).

12. SP 13.13130.2009. Nuclear Power Plants. Fire Safety Requirements. Moscow: Ministry of Emergency Situations of Russia; 2009. (In Russian).

13. State Standard 12.1.004-91. Occupational safety standards system. Fire safety. General requirements. Moscow: Standartinform Publ.; 2014. (In Russian).