Journal of Nuclear Science, Engineering and Technology (JONSAT)
In cooperation with the Iranian Nuclear Society

Thermal-hydraulic analysis of loss-of-cooling accident in spent fuel pool of Bushehr NPP using the RELAP5 and MELCOR

Document Type : Research Paper

Authors

S. Gol Narges 1
S.Kh. Mousavian 2

1 Engineering Faculty, Shahid Beheshti University, P.O.Box: 1983963113, Tehran – Iran

2 Reactor and Nuclear Safety Research School, Nuclear Science and Technology Research Institute, P.O.Box: 14155-1339, Tehran - Iran

https://doi.org/10.24200/nst.2020.1145
Abstract
Following the Fukushima Daiichi accident, the simulation of accidents related to the Spent Fuel Pool (SFP) became more important due to the high content of long-lived radionuclides, and lack of the protection by the pressure vessel despite its low decay heat. Therefore, the loss-of-cooling accident in the SFP of the Bushehr NPP was first simulated in this paper. The RELAP5 (as the Best Estimate code) and MELCOR (as a Severe Accident code) codes were used for simulation of the loss-of-cooling accident. The decay heat power calculation was performed by the ORIGEN code. The nodalization of SFP was done by using the Final Safety Analysis Report (FSAR) of Bushehr NPP. Different phenomena such as increasing water temperature in the pool, water boiling and decreasing of pool water level, spent fuel uncovering, increasing fuel temperature and the onset of fuel melting, hydrogen production, and release of radio-nuclides were observed and investigated. The steady-state results were validated by Bushehr NPP operating data. Verification of transient and accident results was performed by code-to-code (RELAP5 & MELCOR) comparison approach and Bushehr NPP data, the results showed that a good agreement together.

Highlights

1. A.E.O.I., Final Safety Analysis Report (FSAR) for Bushehr VVER-1000 Reactor, (2003).

 

2. J. Fleurot, et al., Synthesis of spent fuel pool accident assessments using severe accident codes, Ann. Nucl. Energy, 74, 58-71 (2014).

 

3. T.E. Collins, G. Hubbard, https://www. nrc. gov/ docs/ML0104/ML010430066. pdf.

 

4. A. Kaliatka, et al., http://downloads.hindawi.com/ journals/stni/2013/598975.pdf.

 

5. M. Adorni, et al., https://www.oecd-nea.org/nsd/ docs/2015/csni-r2015-2.pdf.

 

6. G. Mignot, et al., Large scale experiments simulating hydrogen distribution in a spent fuel pool building during a hypothetical fuel uncovery accident scenario, Nucl. Eng. Technol. 48, 881-892 (2016).

 

7. O. Coindreau, et al., Severe accident code-to-code comparison for two accident scenarios in a spent fuel pool, Ann. Nucl. Energy, 120, 880-887 (2018).

 

8. S. Carlos, F. Sanchez-Saez, S. Martorell, Use of TRACE best estimate code to analyze spent fuel storage pools safety, Prog. Nucl. Energ., 77, 224-238 (2014).

 

9. Z. Huang, W. Ma, Performance of a passive cooling system for spent fuel pool using two-phase thermosiphon evaluated by RELAP5/MELCOR coupling analysis, Ann. Nucl. Energy, 128, 330-340 (2019).

 

10. T.-C. Hung, et al., The development of a three-dimensional transient CFD model for predicting cooling ability of spent fuel pools. Appl. Therm. Eng., 50, 496-504 (2013).

 

11. C. Ye, et al., The design and simulation of a new spent fuel pool passive cooling system, Ann. Nucl. Energy, 58, 124-131 (2013).

 

12. D. Lu, et al., Experiment investigation on pool boiling of the modelled spent fuel tube bundle under partial dry-out conditions, Ann. Nucl. Energy, 121, 461-467 (2018).

 

13. V. Оgnerubov, А. Кaliatka, V. Vileiniškis, Features of modelling of processes in spent fuel pools using various system codes, Ann. Nucl. Energy, 72, 497-506 (2014).

 

14. A. Кaliatka, V. Оgnerubov, V. Vileiniskis, Analysis of the processes in spent fuel pools of Ignalina NPP in case of loss of heat removal, Nucl. Eng. Des., 240, 1073-1082 (2010).

 

15. Allan S. Benjamin, David J. McCloskey, Dana A. Powers, and Stephen A. Dupree, https://www.nrc. gov/docs/ML1209/ML120960637.pdf

 

16. A.E.O.I., Report on safety analyses of Bushehr NPP at extreme external impacts, (2012).

 

17. Z. Zhang, Y. Du, K. Liang, Advanced modeling techniques of a spent fuel pool with both RELAP5 and MELCOR and associated accident analysis, Ann. Nucl. Energy, 110, 160-170 (2017).

Keywords

Bushehr NPP
Spent fuel pool
Simulation
Nuclear codes
Loss-of-cooling
1. A.E.O.I., Final Safety Analysis Report (FSAR) for Bushehr VVER-1000 Reactor, (2003).
 
2. J. Fleurot, et al., Synthesis of spent fuel pool accident assessments using severe accident codes, Ann. Nucl. Energy, 74, 58-71 (2014).
 
3. T.E. Collins, G. Hubbard, https://www. nrc. gov/ docs/ML0104/ML010430066. pdf.
 
4. A. Kaliatka, et al., http://downloads.hindawi.com/ journals/stni/2013/598975.pdf.
 
5. M. Adorni, et al., https://www.oecd-nea.org/nsd/ docs/2015/csni-r2015-2.pdf.
 
6. G. Mignot, et al., Large scale experiments simulating hydrogen distribution in a spent fuel pool building during a hypothetical fuel uncovery accident scenario, Nucl. Eng. Technol. 48, 881-892 (2016).
 
7. O. Coindreau, et al., Severe accident code-to-code comparison for two accident scenarios in a spent fuel pool, Ann. Nucl. Energy, 120, 880-887 (2018).
 
8. S. Carlos, F. Sanchez-Saez, S. Martorell, Use of TRACE best estimate code to analyze spent fuel storage pools safety, Prog. Nucl. Energ., 77, 224-238 (2014).
 
9. Z. Huang, W. Ma, Performance of a passive cooling system for spent fuel pool using two-phase thermosiphon evaluated by RELAP5/MELCOR coupling analysis, Ann. Nucl. Energy, 128, 330-340 (2019).
 
10. T.-C. Hung, et al., The development of a three-dimensional transient CFD model for predicting cooling ability of spent fuel pools. Appl. Therm. Eng., 50, 496-504 (2013).
 
11. C. Ye, et al., The design and simulation of a new spent fuel pool passive cooling system, Ann. Nucl. Energy, 58, 124-131 (2013).
 
12. D. Lu, et al., Experiment investigation on pool boiling of the modelled spent fuel tube bundle under partial dry-out conditions, Ann. Nucl. Energy, 121, 461-467 (2018).
 
13. V. Оgnerubov, А. Кaliatka, V. Vileiniškis, Features of modelling of processes in spent fuel pools using various system codes, Ann. Nucl. Energy, 72, 497-506 (2014).
 
14. A. Кaliatka, V. Оgnerubov, V. Vileiniskis, Analysis of the processes in spent fuel pools of Ignalina NPP in case of loss of heat removal, Nucl. Eng. Des., 240, 1073-1082 (2010).
 
15. Allan S. Benjamin, David J. McCloskey, Dana A. Powers, and Stephen A. Dupree, https://www.nrc. gov/docs/ML1209/ML120960637.pdf
 
16. A.E.O.I., Report on safety analyses of Bushehr NPP at extreme external impacts, (2012).
 
17. Z. Zhang, Y. Du, K. Liang, Advanced modeling techniques of a spent fuel pool with both RELAP5 and MELCOR and associated accident analysis, Ann. Nucl. Energy, 110, 160-170 (2017).

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