LEADIR-PS: The Path to a Safe and Economic SMR

Abstract

Northern Nuclear Industries Incorporated (N2 I2) is developing a family of Small Modular Reactors (SMRs) called LEADIR-PS, an acronym for LEAD-cooled Integral Reactor-Passively Safe. LEADIR-PS plants under development, focused on process heat applications and the energy demands of Canada, are the LEADIR-PS100 with an output of 100 MWth and LEADIR- PS300 with an output of 300 MWth. A plant consisting of six LEADIR-PS300 reactor modules serving a common turbine-generator, called the LEADIR-PS Six-Pack, is focused on serving areas with higher energy demands.LEADIR-PS integrates the inherent safety features of the Modular High Temperature Gas Reactor and molten lead coolant in an integral pool type reactor configuration. Molten lead coolant, which boils at 1750 oC,avoids the cost of a reactor pressure vessel and high pressure/high temperature reactor coolant systems, and the safety concerns regarding pressure vessel and large capacity reactor coolant system piping rupture and precludes evaporation of the coolant. Molten lead does not chemically react with air, water, or graphite.The Gen IV+ LEADIR-PS plants are inherently/passively safe. There are no active systems required for safe shutdown and decay heat removal. Safety is assured without active or stored energy power supply, without a requirement to reposition valves or other devices andoperator intervention or action. The unprecedented safety achieved by LEADIR-PS reactors avoids requirements for a large exclusion radius and demanding evacuation plan requirements.LEADIR-PS, withsteam conditions of 370 oC and 12 MPa (more than twice that of water cooled reactors), can serve over 85% of the world’s non-transportation process heat demands and is ideally suited to serving Combined Heat and Electricity demands and industrial parks. Energy utilization of over 95% is feasible in process heat and Combined Heat and Electricity applications.The simple robust design of LEADIR-PS plants in combination with the integration of proven technologies avoids lengthy research and development programmes thereby facilitating near term deployment. With adequate funding, the first LEADIR-PS unit can be operational within eight years.