Sizing of the Vacuum Vessel Pressure Suppression System of a Fusion Reactor Based on a Water-Cooled Blanket, for the Purpose of the Preconceptual Design

Abstract

A methodology to preliminarily evaluate the size of the suppression tank and the relief pipes for a Vacuum Vessel Pressure Suppression System, to be adopted in a fusion reactor based on a water cooled blanket, is presented. The volume of the ST depends on the total energy of the water cooling system and it can be sized based on a required final pressure at equilibrium, by a simple energy balance. The pressure peak in the VV depends mainly on break area and the flow area of the relief pipes and some suggestions about the method for a preliminarily evaluation of their size are discussed. The computer code CONSEN has been used to perform a parametric study and to verify the methodology.

Passive Hydrogen Recombination during a Beyond Design Basis Accident in a Fusion DEMO Plant

“…In case of in-vessel LOCA, the most important safety system designed to maintain the critical safety function is the VV pressure suppression system (VVPSS). The VVPSS, classified as a SIC-1 system [25], is designed to limit the pressure peak under the allowable value of the VV and to confine the radioactive sources. The current design of the VVPSS includes six separate suppression pools, one of which is dedicated to handle small leakages as shown in Figure 3.…”

Preliminary evaluation of the expansion system size for a pressurized gas loop: application to a fusion reactor based on a helium-cooled blanket

“…Assuming ,0 =8 MPa; • = 2325 m 3 ; , = 318 K ( (318) = 9.52 kPa); ,0 = 673.15 K; = 0.15 MPa, the minimum free volume of the EV will be about 50000 m 3 . An estimation of the water mass in the EV that guarantees the assumed temperature , can be obtained with an energy balance between the helium mass entering in the EV (here assumed to be 80% of the total helium mass in the PHTS), whose temperature drops from ,0 to , , and the water internal energy variation from the EV initial conditions to the final pressure ( , ).…”

“…In analogy with the methodology described in [3] for a pressure suppression system with a water cooled blanket, a preliminary sizing procedure could follow two different steps:…”

Pressure suppression system influence on vacuum vessel thermal-hydraulics and on source term mobilization during a multiple first Wall – Blanket pipe break

“…The VV pressure suppression system is one of the most important safety passive systems to be foreseen in the DEMO plant, since it limits the allowable VV pressure in the event of in-vessel LOCA and confines radioactive sources in the system [1]. For this reason, it is classified as SIC-1 system [2] and its operation should be optimized, ensuring that the evolving system design will satisfy safety requirements and that it is optimized for the safety of personnel, public and environment [3][4] [5].…”