The NRC staff was scheduled to brief the Commissioners on its assessment of performance at USEC's Portsmouth and Paducah facilities during a public meeting on July 16, 1998. That public meeting was conducted, but the NRC staff did not address USEC's performance. The NRC Inspector General is conducting an investigation into the placement of this material into the Public Document Room. The enforcement discretion is necessary to allow continued operation pending the development and submittal for NRC approval of a Certificate Amendment Request to address this concern. This issue has been previously determined to involve an Unreviewed Safety Question.
Risk is defined as probability times consequences.
According to USEC and NRC, there are now two events which have the same probability and consequences of the cylinder drop event. So, the risk is doubled. During a seismic event of 0.05g peak ground acceleration, failure of equipment in both withdrawal facilities would likely occur with releases of liquid UF6.