A series of six out-of-reactor LOCA simulation tests were performed from 2011 to 2012 by Studsvik Nuclear AB, Sweden, under contract with the U.S. Nuclear Regulatory Commission (U.S. NRC). The tests were done on fuel pellets that had been sampled from full-length elements with average burnups ranging from 55 to 72 MWd/kgU. All the fuel elements were of Westinghouse PWR design, with UO2 fuel pellets and first generation ZIRLO (Zr-1.03Nb-0.98Sn by wt%) cladding. The tests were designed to assess the mechanical performance of ballooned and ruptured high burnup fuel rods under typical LWR LOCA conditions; useful information on fuel fragmentation, axial relocation and dispersal were achieved from these tests.