[en] Highly irradiated fuel rods and control rods are used in the Power Burst Facility Severe Fuel Damage (SFD) Test 1-4 to simulate conditions expected during a high-temperature, severe fuel damage accident in a pressurized water reactor. The objective of the test is to provide data on fuel and control rod behavior, hydrogen generation, the release and transport of fission products and aerosols during severe accidents. This paper presents important results from the test based upon the response of on-line instrumentation, analysis of fission product and aerosol data, and postirradiation examination of the fuel bundle. The results from SFD 1-4 provide insight into phenomena governing fuel bundle thermal response, Zircaloy oxidation and hydrogen generation, control rod degradation behavior, core melt progression, fission product release, aerosol generation, and fission product and aerosol deposition and transport