AER working group D on VVER safety analysis – report of the 2008 meeting

The AER Working Group D on VVER reactor safety analysis held its 17th meeting in Garching, Germany during the period 31 March-01 April 2008. The meeting was hosted by the GRS Garching. Altogether 19 participants attend the meeting of the working group D, 16 from AER member organizations and 3 guests from non-member organizations. The co-ordinator of the working group, Mr. S. Kliem, served as chairman of the meeting.
The meeting started with a general information exchange about the recent activities in the participating organizations. The given presentations and the discussions can be attributed to the following topics:
• Code benchmarking
• Safety analysis methodology and results
• Reactor pressure vessel thermal hydraulics
• Future activities
New solutions for the second and the third AER benchmarks were presented and discussed. The second dynamic AER benchmark considers a control rod ejection at hot zero power with Doppler feedback, only. The third AER benchmark concerns the same transient and includes additionally the modeling of thermal hydraulics in the core. S. Kliem (FZD) presented an overview on available solutions for the second benchmark. Additionally, results were presented by G. Alekhin (EDO Gidropress) obtained with the KAMAZ-code and J. Hádek (NRI Řež) using the DYN3D code. S. Bznumi (Nuclear and Radiation Centre Yerevan) presented results for the third and C. Parisi (UniPisa) for the first dynamic AER benchmarks. Two further benchmarks calculated in the frame of the EU-NURESIM project were presented by J. Hádek. K. Velkov (GRS) showed preliminary results on a new coupled code benchmark based on Kalinin-3 data (VVER-1000). A summary of the results of the OECD VVER-1000 coolant transient benchmark was given by N. Kolev (INRNE Sofia) and S. Kliem presented the results of a PWR boron dilution benchmark.
M. Bykov (EDO Gidropress) gave an overview on the results of coolant mixing experiments performed at a VVER-1000 test facility. A new CFD model of a VVER-440 reactor pressure vessel was presented by B. Kiss (TU Budapest). A. Kotsarev (Kurchatov Institute) presented the outline of a envisaged coolant mixing benchmark.
E. Syrjälahti (VTT Helsinki) gave an overview on the real time 3D core model of the new Loviisa training simulator. RIA analyses for the Generation IV HPLWR using KIKO3D/ATHLET were presented by A. Keresztúri (AEKI Budapest) and I. Panka (also AEKI Budapest) presented different hot channel calculation methodologies.