Search

The nuclear industry has claimed that a Fukushima-type event is unlikely to happen in the United States, because few US nuclear power plants are vulnerable to tsunamis. But to some degree, every nuclear plant is vulnerable to natural disaster or deliberate attack, and no nuclear plant can be assumed to withstand an event more severe than the “design-basis accidents” it was engineered to withstand. Many US nuclear plants appear to be subject to greater risks than they were designed to handle, particularly in regard to earthquakes. The author suggests that the US Nuclear Regulatory Commission should expand the universe of events that new and existing nuclear plants must be designed to survive and require reactors to be upgraded accordingly. [ABSTRACT FROM PUBLISHER]

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. [ABSTRACT FROM PUBLISHER]

A great deal of interest has developed recently in the implementation of small reactors in the United States and abroad. Small reactors may offer a significant number of advantages over larger reactors. The diversity of size, design, configuration, and construction features and their planned utilization for nonelectrical power applications as well as traditional power applications pose significant challenges to the current U.S. Nuclear Regulatory Commission (NRC) regulatory structure. The current structure is geared toward nontransportable, commercial, electrical power-producing, light water--cooled reactors utilizing traditional nuclear fuel designs. The NRC is currently engaged in a number of preapplication discussions concerning small reactor designs encompassing three distinctively different technologies. These are integral light water reactors, high-temperature gas-cooled reactors, and liquid metal--cooled reactors. Light water reactor technology-based power generation small reactors will fit best in the current NRC regulatory framework. In response to the anticipated licensing workload, the NRC has implemented organizational changes and has increased its focus in areas supporting the licensing of small reactors. Although the licensing of small reactors has to comply with the requirements imposed by the Atomic Energy Act and the National Environmental Policy Act, there are significant design differences among the various proposed small reactors and the currently licensed reactor designs that result in a number of issues that need to be resolved to properly comply with these statutory requirements. Given the diversity of small reactor designs, a regulatory structure that provides licensing flexibility combined with the required degree of safety assurance would be needed. This is likely to involve a risk-informed and technology-neutral regulatory approach. [ABSTRACT FROM AUTHOR]