Numerical Simulation of an Out-Vessel Loss of Coolant from the Breeder Primary Loop Due to Large Rupture of Tubes in a Primary Heat Exchanger in the DEMO WCLL Concept

Energies

Maria Teresa Porfiri¹  Nicola Forgione²  Marigrazia Moscardini²  Francesco Galleni²  Andrea Pucciarelli² 

[1]ENEA-CR Frascati, Dipartimento Fusione e Tecnologie per la Sicurezza Nucleare, 00044 Roma, Italy

[2]Laboratory of Numerical Simulations for Nuclear Thermal-Hydraulics, Department of Civil and Industrial Engineering, University of Pisa, 56122 Pisa, Italy

关键词: WCLL-BB;    MELCOR;    PHTS;    safety analysis;    DEMO;   

DOI  :  10.3390/en14216916

来源: DOAJ

【 摘 要 】

This work presents a thermohydraulic analysis of a postulated accident involving the rupture of the breeder primary cooling loop inside a heat exchanger (once through steam generator). After the detection of the loss of pressure inside the primary loop, a plasma shutdown is actuated with a consequent plasma disruption, isolation of the secondary loop, and shutoff of the pumps in the primary; no other safety counteractions are postulated. The objective of the work is to analyze the pressurization of the primary and secondary sides to show that the accidental overpressure in the two sides of the steam generators is safely accommodated. Furthermore, the effect of the plasma disruption on the FW, in terms of temperatures, should be analyzed. Lastly, the time transients of the pressures and temperatures in the HX and BB for a time span of up to 36 h should be obtained to assess the effect of the decay heat over a long period. A full nodalization of the OTSG was realized together with a simplified nodalization of the whole PHTS BB loop. The code utilized was MELCOR for fusion version 1.8.6. The accident was simulated by activating a flow path which directly connected one section of the primary with the parallel section of the secondary side. It is shown here that the pressures and the temperatures inside the whole PHTS system remain below the safety thresholds for the whole transient.

【 授权许可】

Unknown