6.0 EVALUATION AND RESULTS
The most reactive pit condition during normal, planned operations is when it is enclosed in High
thick water reflection is a bounding condition for normal operations that permits ease of analysis.
The fissile mass in this pit is substantially less than the water reflected critical mass as published in
LA-10860-MS2, Table XYZ.
Internal pit flooding is arguably an incredible upset condition for planned operations at the NTS.
However, even this condition, combined with thick water reflection, is easily demonstrated to be
far subcritical based on comparisons to critical mass data in Figures XX and YY of LA-10860-
For the pit shipment in an AL-R8 container, a comparative analysis demonstrates that a transport
index of zero is appropriate for criticality control. By comparing fissile masses and dimensions, it
is obvious that the Imaginary Pit is less reactive than the type ABC pit that has been previously
analyzed, shown to have a transport index of zero for criticality control, and approved for
shipment in the AL-R81,3.
DESIGN FEATURES (PASSIVE & ACTIVE) AND ADMINISTRATIVELY
CONTROLLED LIMITS AND REQUIREMENTS
Beyond the design features inherent to the AL-R8, there are no design features or administratively
controlled limits that are required to ensure criticality safety during shipment of the device for the
Imaginary Event. For operations at the NTS, assembly procedures4 limit the number of fissile
components present at any location such that no credible criticality threat is foreseeable.