Leona Woods Leona Woods Leona Harriet Woods (August 9, 1919 – November 10, 1986), later known as Leona Woods Marshall and Leona Woods Marshall Libby, was an American physicist who helped build the first nuclear reactor and the first atomic bomb. At age 23, she was the youngest and only female member of the team which built and experimented with the world's first nuclear reactor (then called a "pile"), Chicago Pile-1, in a project led by her mentor Enrico Fermi. In particular, Woods was instrumental in the construction and then utilization of geiger counters for analysis during experimentation. She was the only
Aqueous homogeneous reactor hoped to design liquid-fuel reactors that would dispense with the costly destruction and processing of solid fuel elements. The formation of gas bubbles in liquid fuels and the corrosive attack on materials (in uranyl sulfate base solutions), however, presented daunting design and materials challenges. Enrico Fermi advocated construction at Los Alamos of what was to become the world’s third reactor, the first homogeneous liquid-fuel reactor, and the first reactor to be fueled by uranium enriched in uranium-235. Eventually three versions were built, all based on the same concept. For security purposes these reactors were given the code name "water boilers".