28th Symposium of AER on VVER Reactor Physics and Reactor Safety (2018, Olomouc, Czechia)
Reactor physics experiments and code validation (benchmarks)
Tamer Bahadir, Emiliya Georgieva (Studsvik)
Studsvik’s in-core fuel management system CMS5-VVER contains lattice physics code CASMO5-VVER and 3D, steady-state nodal code for the hexagonal geometry, SIMULATE5-VVER. The nodal solver of SIMULATE5 along with preliminary benchmarking activities were presented in last year’s AER meeting.
The first part of this paper outlines the calculation of pin-powers in SIMULATE5-VVER: Heterogeneous pin powers are calculated by modulating multi-group homogenous pin powers obtained from the nodal solver of SIMULATE5-VVER with pin form factors, typically in two-groups, from single-assembly CASMO5-VVER lattice calculations.
The second part of the paper demonstrates the accuracy of the nodal and pin power solutions obtained with CMS5-VVER for two numerical benchmarks that are well known in the AER community: the FULLCORE and MIDICORE VVER-1000 benchmarks. These benchmarks, developed by the Skoda JS a.s. group, model the realistic initial cores of a VVER-1000 reactor at cold state point in 2D dimensional geometry for which the reference solutions obtained with Monte Carlo codes MCNP6 and SERPENT: The core reactivity, assembly and pin-by-pin power distributions computed with CMS5-VVER are compared to the reference solutions.