BEPU approach for WWER safety analysis in RIA
26th Symposium of AER on VVER Reactor Physics and Reactor Safety (2016, Helsinki, Finland)
Reactor dynamics and safety analysis
Abstract
BEPU APPROACH FOR WWER SAFETY ANALYSIS IN RIAI.Bilodid, I.Ovdiienko, M.IeremenkoState Scientific and Technical Centre on Nuclear and Radiation Safety, Kyiv, Ukraine Stusa st. 35-37, 03142 Kyiv, Ukraine yn_ovdienko@sstc.com.uaT. LötschTÜV SÜD Industrie Service GmbH, Energy and Systems (IS-ES), Munich, Germany Westendst. 199, 80686 Munich, Germany thomas.loetsch@tuev-sued.deABSTRACTAt present time, Ukraine faces the problem of small margins of acceptance criteria in connection with the implementation of a conservative approach for safety evaluations. The problem is particularly topical conducting feasibility analysis of power up-rating for Ukrainian nuclear power plants. Such situation requires the implementation of a best-estimate approach on the basis of an uncertainty analysis. For some kind of accidents, such as loss-of-coolant accident (LOCA), the best estimate approach is, more or less, developed and established. However, for reactivity initiated accident (RIA) analysis an application of best estimate method could be problematical. A regulatory document in Ukraine defines a nomenclature of neutronics calculations and so called “generic safety parameters” which should be used as boundary conditions for all VVER-1000 (V-320) reactors in RIA analysis. In this paper the approach of realization of generic safety parameters as uncertainty parameters for RIA analysis with the use of the stand-alone 3D neutron kinetic code DYN3D, coupled version of DYN3D/ATHLET and the GRS SUSA approach are presented.The results of mentioned approach application in comparison a conservative approach results are presented.The work was performed in the framework of the project BMUB/GRS 3614R01520 under German BMU support. 26th Symposium of AER on VVER Reactor Physics and Reactor Safety 37 10 – 14 October 2016, Helsinki, Finland