This paper deals with quantitative accuracy assessment
of MELCOR code capability to predict ThermalHydraulic (TH) response of PSB-VVER Integral Test
Facility (ITF) during Station Black-Out (SBO) accident.
The PSB-VVER is a full-height, 1:300 volume and
power scale representation of a VVER-1000 nuclear
power plant and has been widely used in validation of
TH codes for VVER-1000 applications. A MELCOR
nodalization has been developed for modeling SBO
accident in PSB-VVER ITF and Fast Fourier Transform
Based Method (FFTBM) method has been used to assess
the code prediction with experimental data. The FFTBM
has been widely applied to a number of comparisons
involving separate and integral test facilities experiments.
The FFTBM shows the measurement–prediction
discrepancies (accuracy quantification) in the frequency
domain. For accuracy quantification of MELCOR
predictions for SBO accident, the FFTBM was applied to
28 selected TH variables. It is observed that there is a
good agreement between MELCOR predictions and
PSB-VVER measured data, and results of quantitative
analysis are in acceptable range of quality for most of the
parameters.