Comparison of VNEM to Measured Data from Ringhals Unit 3 IACIP, NKS-R-2008-61
Makoto Tsuiki, Steven Mullet, William H. Beere
Comparisons have been made of a LWR core simulator CYGNUS with VNEM neutronics module to the measured data obtained from Ringhals unit 3 NPP at the hot-operating condition at its beginning of cycle 1 (core average burnup = 0 through 500MWD/MT).
The results can be summarized as:
core eigenvalue = 0.99711 +/- 0.00067
Excellent agreement was obtained in the comparison of the neutron detector readings as observed in Phase 1 (2008).
The computing (CPU) time was measured to be 7.5 min. / case, which is about 1/3 of the prototype VNEM code. This is because of the sophisticated coding of VNEM module in CYGNUS and the convergence acceleration effect of the feedbacks.