Calculation assessment of the critical components of the primary circuit of the Jaslovske Bohunice NPP (units 3 and 4) within the LBB project

The procedure and the results are described of a check calculation of critical sections of the Jaslovske Bohunice V-2 primary circuit, performed within the Leak Before Break (LBB) project. The calculation based on the finite element method was applied to each section that, subjected to calculation by the BASLBB program package, failed to meet the condition that the circumferential crack where plastic collapse takes place on a superimposed load, is at least twice as large as a crack through which 38 litres of coolant would leak in a minute. The check calculation gave evidence that if a less conservative approach than in the BASLBB system is applied, all sections meet the above requirement. The application of the less conservative approach does not detract from the accuracy of calculation and/or from the determined safety of the system: on the contrary, the solution is closer to the actual situation. 6 tabs., 19 figs., 6 refs