Complex sentence: The analysis of the debris at the 10-megaton "Ivy Mike" nuclear test was a part of long-term project, one of the goals of which was studying the efficiency of production of transuranium elements in high-power nuclear explosions.
Split into simpler sentences: The analysis of the debris at the 10-megaton "Ivy Mike" nuclear test was a part of long-term project. One of the goals of which was studying the efficiency of production of transuranium elements in high-power nuclear explosions.