Limitations affecting boiler operation
Pressurized water reactors

The main condition to be met is that there must be no damage to the cladding (the "first barrier" against the risk of disseminating radioactive elements) for all cases of normal operation (category 1) and moderate-frequency incidents (category 2). Limited damage is tolerated for infrequent faults (category 3) and hypothetical accidents (category 4), but the core must continue to cool properly.

A first limit resulting from the above condition is the non-fusion "at the core" of the fuel (= at the center of the pellets). This corresponds to a limit on linear power (i.e. per unit height). A limit on steady-state linear power must also be respected in order to limit residual energy in the pellets to meet the criteria for a loss-of-coolant...