Multi-step planning calculations with the GOTHIC code used for the design of complex experiments in the PANDA facility

Large Scale Experiments Representing a Containment Natural Circulation Loop during an Accident Scenario

“…Vessels 1 and 2 represent the upper dome of the containment in a two-room concept (see VB2) and Main Vent line 2 (MV2). The use of the lines was supported by extensive scoping calculations conducted with GOTHIC Andreani et al [5] which confirmed the formation of a natural circulation loop mobilizing the full height of the facility in the HP6 test scenario. The VB lines have an inner diameter of 134 mm whereas the MV2 line has an inner diameter of 109 mm.…”

“…The experiments address the flow and the gas distribution in a generic two-room configuration which can be found in various reactor designs such as the equipment room and outer zone of the EPR6 which are not connected under normal operation conditions or the fuel machine vault/pump room of a PHWR Andreani et al [5]. Scaling issues such as the ratio between the volume of the inaccessible area and the total volume in the two-room concept should be approximately reproduced in the tests in PANDA are covered and discussed in Andreani et al [5].…”

“…The experiments address the flow and the gas distribution in a generic two-room configuration which can be found in various reactor designs such as the equipment room and outer zone of the EPR6 which are not connected under normal operation conditions or the fuel machine vault/pump room of a PHWR Andreani et al [5]. Scaling issues such as the ratio between the volume of the inaccessible area and the total volume in the two-room concept should be approximately reproduced in the tests in PANDA are covered and discussed in Andreani et al [5]. In the two-room concept, natural circulation is established in a LOCA accident scenario between the inner rooms (inaccessible area) and the outer containment, following the opening of rupture and convective foils (constituting the Pressure Equalization Ceiling, PEC), as well as dampers ( Figure 1 as well as Andreani et al [5] and Dimmelmeier et al [4]).…”

“…Scaling issues such as the ratio between the volume of the inaccessible area and the total volume in the two-room concept should be approximately reproduced in the tests in PANDA are covered and discussed in Andreani et al [5]. In the two-room concept, natural circulation is established in a LOCA accident scenario between the inner rooms (inaccessible area) and the outer containment, following the opening of rupture and convective foils (constituting the Pressure Equalization Ceiling, PEC), as well as dampers ( Figure 1 as well as Andreani et al [5] and Dimmelmeier et al [4]). The expected flow path is depicted in Figure 1(b) with upwards flow through the foils in the broken loop, downward flow along the containment wall and flow through the dampers.…”

“…However, both experiments are not intended to address the reactor concepts directly, but the specific designs were only considered to obtain some meaningful figures for the main geometrical data, reasonable severe accident sequences from open literature and to derive a generic two-room containment concept Andreani et al [5]. Based on extensive preliminary calculations by Andreani et al [5] the objectives of the HP6 series were twofold: to reproduce as much as possible the main features of the containment response for these idealized accident scenarios and to create an experimental database suitable for the assessment of advanced computational tools (e.g., Lumped Parameters (LP), 3D-type codes and CFD codes) for the analysis of the flow transport in a multicompartment containment. However, some of the axis scales in the figures of the present paper are presented in nondimensional form, because the data of the OECD HYMERES project belongs to the project participants.…”