The design of nuclear power stations to allow for natural hazards such as tsunami / earthquake is tailor made for the local situation around the site of the power station. Design factors include local geology, seismic stability, tidal level and possible flooding, available cooling water and extreme heat or cold.

Design against earthquake - key buildings, systems and facilities of Daya Bay are designed to withstand earthquake at Modified Mercalli Scale Level VIII*.

Design withstands tidal waves and flooding - the whole site is built 6.5 metres above local sea level and protected by an off-shore breakwater of 17 metre high, providing defence against the possible impact of flooding.

Safe operation is the top priority for all nuclear power stations. The defence-in-depth principles are adopted in all key areas including plant design, equipment installation and operation to ensure nuclear safety. It comprises several levels of protection, in case of a failure in operation or mistakes due to human error, back-up measures can be put in place to identify the problem and minimise the chance of any severe consequences.

* The Mercalli Scale (from Level 1 to Level XII) measures the intensity of the effect of an earthquake at a certain location whereas the Richter Scale measures the power of an earthquake.