Spent Nuclear Fuel: Defense-in-Depth
Defense-in-Depth Defined: Multiple layers of defense to protect against accidents and their effects to ensure the risk to the public is acceptably low. – Nuclear Regulatory Commission
The nuclear energy industry is built on a foundation of the concept of defense-in-depth, a philosophy to have multiple, independent layers of protection between fission products, such as spent nuclear fuel, and the environment or public.
For a working nuclear reactor, that means multiple barriers between the fuel pellet in the reactor core and the environment outside the containment dome. At San Onofre Nuclear Generating Station, defense-in-depth is focused on the storage of spent nuclear fuel in dry casks. Here too, the concept is embraced and utilized to maximum effect.
Defense-in-depth, and its attributes, is an ongoing point of discussion and education during Community Engagement Panel meetings. Below we have gathered and categorized each DiD presentation to aid better understanding of the concept and how it is being utilized at SONGS.