[en] Fuel rods which contained defects representative of defects occasionally found in commercial PWR reactor fuel rods were tested under power ramp and film boiling operation. The results of these tests, part of a larger Nuclear Regulatory Commission program to study the behavior of fuel rods during off-normal operation, are described in the report. The cladding defects included a hydride rupture, a pinhole-type defect, and an axial crack. Operation of defective fuel rods in a power ramp and for a short time in film boiling did not seriously aggravate the condition of the rods beyond that experienced by intact rods undergoing the same transient. Although embrittlement occurred in the cladding in excess of that found in unfailed rods, the defective rods withstood the stresses associated with the quenching of film boiling conditions. Fuel washout occurred where large, open cladding defects were present. No molten fuel-coolant or molten fuel-cladding reactions were observed in the defective rods