Performing pin‐by‐pin calculations in the frame of Kalinin‐3 benchmark
26th Symposium of AER on VVER Reactor Physics and Reactor Safety (2016, Helsinki, Finland)
Reactor dynamics and safety analysis
Abstract
MULTISCALE APPLICATION OF SYSTEM CODE ATHLET FOR DETAILED VVER CORE ANALYSISS. Nikonov1, I. Pasichnyk2, K. Velkov21GRS scientific guest, Moscow, Russia2Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) gGmbH, Garching, GermanyABSTRACTThis paper sums up intermediate results of research efforts aimed to develop a detailed in-vessel ATHLET VVER-type reactor model. It is shown, that together with the development of the input data deck preprocessor, this activity also requires substantial changes in the ATHLET code itself with a goal to accelerate calculations and reduce wallclock time of the simulations. The results of the code evolution are reported and it is shown that for the generic VVER input data deck the speedup factor of 170 is achieved. The turbulent model which takes into account turbulent mass exchange between connected thermohydraulic objects with different level of nodalization is tested. A testbed for the model development and verification serves the OECD/NEA benchmark Kalinin-3 (K3). Calculations of the coolant state distributions in the active core are carried out for assemlbywise as well as pinwise nodalization of the selected fuel assemblies. An achieved progress allows within one system code ATHLET to cover wide spectrum of problems starting from the detailed description of processes in the fuel assembly head up to the description of global parameters of primary and secondary loops of the nuclear reactor facility. It substantially increases the area of possible ATHLET code applications compared to its initial purposes defined by the first designers of the code. Future directions are outlined which mainly concerns the development of the simulation ecosystem which will be able to perform coupled neutronphyiscal and thermohydraulic pin-by-pin calculations.26th Symposium of AER on VVER Reactor Physics and Reactor Safety 42 10 – 14 October 2016, Helsinki, Finland