Ventilation system concepts for the simplified passive ALWRs

As part of the ongoing advanced light water reactor (ALWR) programs, designs are being developed for 600 MWe class plants such that, for any set of credible events, plant safety can be assured by actuating a set of emergency systems, including systems that can operate passively and maintain plant safety for 72 hours. A particular challenge in the development of these designs is to provide for the plant emergency ventilation needs by passive means only. The present paper briefly describes conceptual designs that could be applied for performing the plants' normal and emergency ventilation functions. For handling emergencies, the proposed designs rely on using pressurized liquid air acting through double stage educators for ambient air cooling, purification, and inward or outward leakage control. Early evaluation of these proposed designs, and any other available option, is recommended to avoid delays in the overall S/ALWR plant's development