The PARAMETER test series

The PARAMETER programme investigates phenomena associated with reflooding of a degrading Pressurized Water Reactor (both Western and VVER type) like core under postulated severe accident conditions, in an early degradation phase when the geometry is still mainly intact. The objective of the presented out-of-pile test series is both the experimental and computational investigation of a 19-fuel rods bundle behaviour under severe accident conditions including the stage of low rate flooding from bundle top or high-rate flooding from bottom and top. The studies are performed according to the Work Plan of ISTC Project#3194 "Fuel assembly tests under severe accident conditions". The PARAMETER programme is being realized jointly by the leading organizations of the Federal Atomic Energy Agency of the Russian Federation: FSUE EDO "GIDROPRESS", IBRAE RAS, FSUE SRI SIA "LUCH". The project is performed under financial support by ISTC and in close cooperation with leading European R&D organizations such as FZK, GRS (Germany), CEA, EDF and IRSN (France). The paper will provide the information on scope of work as already completed or planed in framework of PARAMETER-SF test series. Some outcomes from PARAMETER-SF1 and PARAMETER-SF2 tests will be presented for discussion. In the PARAMETER-SF1 experiment the behaviour of VVER-1000 assembly overheated up to 2000ºС under top flooding conditions was studied. In another PARAMETER-SF2 experiment the efficiency of the combined top and bottom flooding was studied for the VVER-1000 assembly overheated to 1500ºС. An outlook will be given for the foreseen experiment PARAMETER-SF3 (top flooding). The experimental part of PARAMETER project is supported by intensive analytical support. For this purpose widely used codes for NPP safety assessment were involved. Considerable contribution to the success of the PARAMETER project was provided by teams from Russia (SOCRAT, PARAM-TG, ICARE/CATHARE, and RELAP codes), France (MAAP4) and Germany (ATHLET-CD). So in the paper some results of pre- and post-test modelling and outcomes from code-to-code and code-to-data comparisons will be presented for both SF1 and SF2 tests as well.