US nuclear regulators reject easier safety math for new reactor designs

US nuclear regulators rejected a proposal to change how they calculate a key safety measure for new reactor designs. This means new nuclear power plants, like those from NuScale Power, must continue to use the existing, more conservative method for predicting how reactor steel ages.

The US nuclear industry has been trying to streamline the licensing process for advanced reactor designs. This decision means one specific technical hurdle remains in place. Companies building smaller, modular reactors will still have to prove their designs are safe using methods originally developed for much larger, older reactor types.