Large-Scale Tests Performed in Support of LBB Projects Applied to WWER Type NPPs in the Czech Republic in Years 1992–1994

In the paper, an overview of large-scale experiments performed on components of WWER primary circuits within several LBB projects conducted in the Czech Republic in years 1992 – 1994 is presented. The tested components were replicas of the real ones; they contained a through-wall crack and were loaded by pressure and bending moment in two stages, as appropriate according to the LBB methodology. All tested components exhibited stable behaviour under normal operating loading superposed with safe shutdown earthquake loading (NOC + SSE) applied during 1^st stage of experiment. During 2^nd stage of experiment, under loading by bending moment only, the models usually exhibited stable tearing of the crack, in some cases limit load (maximum force at loading controlled by displacement) was reached. In the paper, the experiments are briefly described, with presenting the main experimental and (in some cases) FE computational results.