Walter Zinn

Walter Zinn was the physicist behind the EBR-I project. The first director of Argonne National Laboratory in Illinois, Zinn originally proposed the EBR-I’s construction as a means to alleviate the post-World War II shortage of fissionable materials by breeding plutonium. Although much of his time was spent building components in Chicago, his team brought the finished reactor to Idaho and installed it in the EBR-I facility. He was present when electricity was first generated by nuclear power on December 20, 1951, illuminating a string of four light bulbs. After demonstrating that the breeder reactor principle was sound, Zinn proposed EBR-II, a larger-scale reactor used to test nuclear hardware.