EQ6 Calculations for Chemical Degradation of Fast Flux Test Facility (FFTF) Waste Packages

Fuel from the Fast Flux Test Facility ' (FFTF) has been considered for disposal at the proposed
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 outer corrosion-allowance barrier and corrosion-resistant barrier (CRB) may breach3, 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.