EQ6 Calculations for Chemical Degradation of Enrico Fermi Spent Nuclear Fuel Waste Packages

The Monitored Geologic Repository (MGR) Waste Package Operations (WPO) of the Civilian Radioactive Waste Management System Management & Operating Contractor (CRWMS M&O) performed calculations to provide input for disposal of spent nuclear fuel (SNF) from the Emico Fermi Atomic Power Plant (Ref. 1). The Fermi fuel has been considered for disposal at the potential Yucca Mountain site. Because of the high content of fissile material in the fuel, the waste package (WP) design requires special consideration of the amount and placement of neutron absorbers, and the possible loss of absorbers and fuel materials over geologic time. For some WPs, the corrosion-allowance barrier and the corrosion-resistant material (CRM) may breach (Refs. 2 and 3), allowing the influx of water. Water in the package may moderate neutrons, increasing likelihood of a criticality within the package; and the water may, in time, gradually leach the fissile components and neutron absorbers from the WP, further affecting the neutronics of the system.