Following local damage it is important to contain the existing damage as locally as possible and to prevent the spread of damage. One must consider a plant protective system, multiple path inlets to assemblies to avoid blockage, strong assembly canning to contain any local failure, and emergency core cooling system (and pony motors on main pumps) to avoid failure after loss of cooling.

3.4.3.2 Prevention of Criticality Following Fuel Melt-down (Consequence Limiters)

The core fuel after fuel melt-down would need to be prevented from accumulating into a critical mass (see also Section 5.6.1). Preventatives could include large heat sinks at subassembly inlets to freeze molten fuel from single subassembly, dispersion cones in and out of vessel, melt catchers (assembly or core size), terminal cooling systems, or ground disposal to permanently avoid criticality.