28th Symposium of AER on VVER Reactor Physics and Reactor Safety (2018, Olomouc, Czechia)
Reactor physics experiments and code validation (benchmarks)
A.V. Baykov, A.V. Kotsarev, S.V. Tsyganov (NRC Kurchatov Institute)
During the start-up of the Unit 1 of Novovoronezh NPP-2 (VVER-1200) the extensive programme of physical tests at hot zero power was carried out. Several tests were designed in such a way to use asymmetrical flux disturbances for measurement of important parameters of the core and control and protection system. These tests include measurements of control rod worth by rod drop and by its slow movement in a different state; measurements of rod group efficiency; emergency protection worth measurement.
This kind of tests is also interesting for the purpose of verification and validation of three-dimensional dynamic codes. The paper presents and discusses results of test simulation by means of ATHLET/BIPR-VVER code, which is now widely used for the VVER safety analysis. Standard system code was equipped with the models of ex-core ion chambers to simulate its currents and reactivity readings, which were the most important experimental parameters of the tests.