EXPERIENCES WITH DYN3D FOR SAFETY ANALYSES OF VVER-440 REACTORS
24th Symposium of AER on VVER Reactor Physics and Reactor Safety (2014, Sochi, Russia)
Reactor dynamics and safety analysis
Abstract
EXPERIENCES WITH DYN3D FOR SAFETY ANALYSES OF VVER440 REACTORS
Ctibor Strmenský
VUJE, Inc. Trnava, Slovakia ctibor.strmensky@vuje.sk
ABSTRACT
The history of using the dynamic code DYN3D in VUJE started 1994 and continued uptonow. The first version DYN3D code was version M2/M3 (up to 1999), next version H1.1 was used from 2001 to 2006 and present version 3.2 is used from 2006 upto now. DYN3Disdynamic code for pressurized reactors (PWR, VVER440/1000). DYN3D code is used for startup calculations and safety analysis.
In 2002 – 2004, we participated in international project VALCO, that was concerning to validation of dynamic and thermohydraulic codes and during 2010 – 2011, we participated in international project LWR-DEPUTY, that was concerning to development of the new combine-transmutation VVER-440 assembly based on the Mo matrix.
Preparation of input deck data is divided into several steps. At the start is necessary processing burnup data (BIPR7) with library of fuel data (HELIOS) into several blocks (cross-section data, feedback coefficients data, poison data (Xe, I, Sm, Pm), prompt and thermal neutron data, data of delay neutrons, neutron velocity data). All parameters are prepared for each fuel assembly. During finalisation process, all input data are formated into defined format. Several data areprepared in independent files (poison data, geometric and physics data for 59 assemblies, thermohydraulic data for whole core, hot channel data). One of key parameter is geometric data of the core. In past, we used 10 axial layers (2001 – 2005), where we obtained 3490 nodes (10*349). Next we extended to 20 axial layers model (2005 – 2010), where we obtained 6980 nodes (20*349). The present model contains 42 axial layers, that corresponds to 14658 nodes (42*349).
Second part of preprocessing is adjustment process, during input deck data are corrected by correction parameters (boron acid concetration, absorber data, albedo data and etc.).
The postprocessing part contains programs concerning to visualization data for 2D- graphs, 2D-cartograms or 3D-scene (stationary and transient).
Overview of using of DYN3D code in our institute is presented on 8 main interactive slides and 15 auxiliary interactive slides with figures and videos, which demonstrate preprocessing input deck data and postprocessing results.