3.1 Failure Criteria

The first two chapters have emphasized methods of safety evaluation and possible disturbances to the system. The next chapters go through a design process by setting design safety criteria, by reviewing the particular problems of a sodium-cooled design, by containing the system, and finally by licensing the plant.

Before reviewing the safety criteria that are set to define the design of a safe plant and detailing safety features that might be included, it is necessary to consider what failure means. In the previous chapter the system was evaluated to determine its response to a variety of disturbances; in particular to assess whether failure was possible. What is meant by failure?