[en] A study of a large base of experimental and operational data on stress corrosion cracking has shown that many design and operating parameters contribute simultaneously to determining the occurrence of SCC failures. Nearly all of the important parameters, however, derive from or effect two primary parameters, namely fuel temperature and cladding stress or strain. An evaluation and plotting of the fuel temperature and cladding strain during 310 power ramp events has shown that a clear boundary exists which separates failures from non-failures in the fuel temperature-cladding strain space. A fast running calculational model called PREFAIL (for PRE vent FAIL ure) has been developed to calculate the fuel temperatures and cladding strains. The correlations utilized in the calculations are based on a direct statistical correlation of large amounts of data generated at the OECD Halden Reactor Project. The model includes the most important parameters affecting fuel temperature and cladding strain including pellet-cladding gap, densification, temperature dependent swelling, burnup, cladding creepdown, and cladding thickness. Other effects which are treated inherently by the location of the failure boundary are fission product release and fuel creep/plasticity. It is believed this type of failure model provides a good compromise between detailed mechanistic models, which require extensive inputs and long running times, and solely empirical models which consider too few parameters (i.e. power and burn-up only)