Moving to passive designs

The events at Fukushima Daiichi have greatly renewed the public focus on the safety of the existing fleet of nuclear reactors, especially as many US reactors share the same fundamental design—and safety systems—as the affected Japanese reactors. The authors explore the proposition that a transition to increasingly passive safety features in new advanced reactor designs— supplementing, and in some cases superseding, the existing approach of depending on active “defense-in-depth” safety systems—could significantly reduce reactor safety risks. Such passive safety features are highly developed in new small modular reactor designs now under thorough study, designs that may also markedly improve the economic case for nuclear power, based on a factory-built reactor approach. These reactors offer the possibility that US-based manufacturers could regain a significant share of the international nuclear reactor market.