Results of the four PBF severe fuel damage tests

Four in-pile severe fuel damage tests have been conducted in the Power Burst Facility as part of the US Nuclear Regulatory Commission's (USNRC) Severe Accident and Source Term Research Program. The tests included 1-m long bundles of PWR fuel pins and simulated the thermal-hydraulic and fuel damage conditions of a severe core damage accident. Tests were run with both low and high burnup fuel, low and high coolant flow and with slow and rapid cooldown. One test included Ag-In-Cd control rods. The various types of fuel damage that occurred in the four tests are presented and the measured hydrogen generation, fission product release, and aerosol behavior are described. The principal benefits of the test program have been to improve the USNRC's severe accident analysis capability. Some of the computer models affected by the test results are discussed in the paper