Coupling to System Codes

DYN3D / ATHLET 1)

DYN3D is coupled to the thermal-hydraulic system code ATHLET for analyzing more complex transients. Three different methods are used for coupling:

Internal coupling

 
  • Neutron kinetics of DYN3D
  • Thermal hydraulics of core and coolant system modelled by ATHLET

External coupling

 
  • Neutron kinetics and thermal hydraulics of core modelled by DYN3D
  • Thermal hydraulics of the remaining coolant system modelled by ATHLET
 

Parallel coupling

 
  • Neutron kinetics and thermal hydraulics of core modelled by DYN3D
  • Thermal hydraulics of the core and the coolant system modelled by ATHLET
1)   ATHLET is developed by the Gesellschaft für Anlagen- und Reaktorsicherheit (GRS).

DYN3D / RELAP5

DYN3D is coupled to the thermal-hydraulic system code RELAP5 by the Institute of Physics and Power Engineering, Obninsk. The method of internal coupling is used.

Validation of Coupled Codes

  • Comparison with other codes
  • 5th Dynamic AER Benchmark: Main Steam Header Break in a NPP with VVER-440 Reactor
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  • 6th Dynamic AER Benchmark: Main Steam Line Break in a NPP with VVER-440 Reactor
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  •  OECD Main Steam Line Break Benchmark for TMI-1
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  • OECD/NEA VVER-1000 Coolant Transient Benchmark Phase 2 (V1000CT2): Main Steam Line Break Analysis
 in progress
  • Comparison to measurements and with other codes
  • Turbine load drop test in the nuclear power plant (NPP) Loviisa-1 with VVER-440 reactor (EU PHARE Project SRR 1/95)
  • Start-up test: Turning-off one from two feedwater pumps in the NPP Balakovo-4 withVVER-1000 reactor (EU PHARE Project SRR 1/95) 
  • Start-up test: Switch-off of one of three working main coolant pumps at 65 % power at the VVER-1000 NPP Kozloduy-6 (EU Project VALCO)
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  • OECD BWR  Turbine Trip Benchmark (NPP Peach Bottom)
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  • OECD/NEA VVER-1000 coolant transient benchmark Phase 1 (V1000CT1):  Start-up test: Switch-on of one main coolant pump at 30 % power at the VVER-1000 NPP Kozloduy-6
PDF-ICON

NPP Balakovo-4:
Comparison of the results of the DYN3D/ATHLET calculations with the measured power behaviour. Influence of the constant and dynamic heat transfer coefficient (HTC) calculated by the DYN3D gas gap model.