In 1938, she researched the action of neutrons on the heavy elements. This was an important part of the discovery of the nuclear fission of uranium. Curie became Professor in the Faculty of Science in Paris in 1937. She became Director of the Radium Institute in 1946. After six years as a Commissioner for Atomic Energy, Curie took part in the construction of the first French atomic pile in 1948. Its construction was continued after her death by her husband.