Safety Features of the NuScale Design

In designing the NuScale Power Module and power plant, NuScale has achieved a paradigm shift in the level of safety of a nuclear power plant facility. It is a revolutionary solution to one of the biggest technical challenges for the current fleet of nuclear energy facilities. NuScale has developed a safety system that does not require DC batteries to place the plant in a safe cool-down condition following an extreme event.

The NuScale plant, with its unique design, has achieved the Triple Crown^sm for nuclear plant safety: to safely shut down and self-cool, indefinitely, with:

• No Operator Action
• No AC or DC Power
• No Additional Water

This breakthrough eliminates the DC batteries usually needed to align valves and to power systems needed to provide cooling of the nuclear core. Safety valves align in their safest configuration on loss of all plant power.

Comprehensive safety features are incorporated to provide stable long-term nuclear core cooling under all conditions, including severe accidents. These safety features include:

• High-pressure containment vessel, redundant passive decay heat removal, and containment heat removal systems.
• Natural circulation for emergency cooling, decay heat removal, and containment cooling, eliminating the need for primary pipes and pumps and hazards from any associated failures.
• Safely shut down and self-cool, indefinitely with no operator action, no AC or DC power, and no additional water – the Triple Crown for nuclear plant safety.
• Submerged containment vessel capable of withstanding both seismic forces and pressure transients produced by a complete and simultaneous rupture of any or all of the reactor piping internal to containment.
• A small nuclear fuel inventory, since each 45 MWe NuScale Power Module houses approximately 5% of the nuclear fuel of a conventional 1,000 MWe nuclear reactor.
• A reactor pool that serves as an “in-situ” ultimate heat sink for core cooling housed in a Seismic Category 1 reactor building.
• Smaller and simpler emergency plan without reducing public safety, with an emphasis on protective actions close to the site, avoiding the impact of an unnecessary evacuation, and minimizing the complexity and cost of emergency plan maintenance for local emergency management around the site.