ANDREA 2.2 ‐ advances in modeling of VVER cores, ÚJV Řež
26th Symposium of AER on VVER Reactor Physics and Reactor Safety (2016, Helsinki, Finland)
Advances in spectral and core calculation methods
Abstract
ANDREA 2.2 AND 2.3 – ADVANCES IN MODELING OF VVER CORESFrantišek Havlůj, Jonatan Hejzlar, Radim Vočka, Jiří Vysoudil ÚJV Řež a.s., Czech RepublicABSTRACTIn 2016 a new version of code ANDREA for core design and reload safety analysis of VVER reactors has been released. The new code version includes several major improvements. The first of them is a seamless incorporation of short time kinetics calculations (without temperature feedback) into the code. Evaluation of transients starting from any zero power state during the cycle is possible. This new feature accompanied by the possibility of ex-core detector signal predictions enables precise interpretation of dynamic measurements of control assembly weight during the reactor start-up. Second important enhancement resides in new flexible format of cross section libraries and in new fuel temperature model based on results of TRANSURANUS fuel performance code. From the user point of view the code now has only one cross section library covering whole range from cold states to reactor full power operation. Furthermore for the new version 2.3 which is to be released shortly we have implemented the possibility of fluent control assemblies motion and of non-equidistant axial nodalisation schemes in VVER- 440 calculations. New implementation of control assembly movement affects also calculations with control rods, where the cusping effect is eliminated.The new code version has been thoroughly tested and validated for both VVER-440 and VVER- 1000 reactors.26th Symposium of AER on VVER Reactor Physics and Reactor Safety 5 10 – 14 October 2016, Helsinki, Finland