German Standard Problem No. 6: 'Rupture of a steam line within the HDR containment leading to early two-phase flow (V-44)'

Objective of the experiment was the investigation of the containment behaviour after a rupture of the main coolant line under nearly realistic conditions, such as large vent openings between the compartments of the containment, installations and almost full scale dimensions. Particularly the objectives include mechanical and thermal loads upon the containment structures caused by the energy and mass flow through the ruptured steam line into the containment (fig. I). The participants of the standard problem No. 6 were supposed to calculate for three time periods (short time period 0 - 2 seconds, medium time period 0 - 50 seconds, long time period 0 - 1500 seconds) the following variables: Time-dependent pressure and temperature buildup in the various containment compartments; time history of differential pressure between adjacent containment compartments; heat transfer to the containment structures. Except some isolated deficiencies in the physical models the analytical methods used for the calculation of containment behaviour are satisfactory for the accuracy needed for the licensing procedure. (orig./HP)