Assertion: neptunium | /r/HasProperty | recovered in secretive operation
Facets:
value: highly
type: DEGREE
value: from november
type: TEMPORAL
Source sentences:
text: Neptunium was recovered from uranium hexafluoride waste and fluorination ash in an apparently highly secretive operation from November 1958 until at least 1960 at the Paducah Gaseous Diffusion Plant.