This paper deals with the problem of scaling complex scenario measured in experimental facilities and replicated by the use of Relap5 code. ‘Kv-scaled’ calculation plays an important role in the frame of the “on-transient qualification” of the nodalization (following the procedure envisaged at Pisa University) and to evaluate the importance of some scale-distortions in boundary and initial conditions, which are foreseeable for the plant in comparison with the transients, performed in the facilities. This is the way in order to demonstrate that the “nominal” calculation can be considered the "best estimate" prediction of the plant performance in the case of the transient considered. All these steps are part of the uncertainty methodology (Uncertainty Methodology based on Accuracy Extrapolation - UMAE), developed at Pisa University. The reference data base for the activity is the Small Break Loss Of Coolant Accident (SBLOCA) transient, counterpart of the LOBI facility experiment, that has been performed in the Integral Test Facility (ITF) PSB-VVER, installed at EREC (Electrogorsk, Russia), in the framework of the OECD PSB-VVER Project. The calculation (PSB and Nuclear Power Plant) has been performed using Relap5/Mod3.3 beta computer code and its accuracy has been demonstrated by the qualitative evaluation reported in the present document.
Scaling of small break LOCA in VVER 1000 system
D'AURIA, FRANCESCO SAVERIO;
2005-01-01
Abstract
This paper deals with the problem of scaling complex scenario measured in experimental facilities and replicated by the use of Relap5 code. ‘Kv-scaled’ calculation plays an important role in the frame of the “on-transient qualification” of the nodalization (following the procedure envisaged at Pisa University) and to evaluate the importance of some scale-distortions in boundary and initial conditions, which are foreseeable for the plant in comparison with the transients, performed in the facilities. This is the way in order to demonstrate that the “nominal” calculation can be considered the "best estimate" prediction of the plant performance in the case of the transient considered. All these steps are part of the uncertainty methodology (Uncertainty Methodology based on Accuracy Extrapolation - UMAE), developed at Pisa University. The reference data base for the activity is the Small Break Loss Of Coolant Accident (SBLOCA) transient, counterpart of the LOBI facility experiment, that has been performed in the Integral Test Facility (ITF) PSB-VVER, installed at EREC (Electrogorsk, Russia), in the framework of the OECD PSB-VVER Project. The calculation (PSB and Nuclear Power Plant) has been performed using Relap5/Mod3.3 beta computer code and its accuracy has been demonstrated by the qualitative evaluation reported in the present document.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
