Demonstrating compliance with regulatory activity limits during initial SNS operations

During initial SNS operations, beam-on-target will be limited to maintain target radionuclide inventories below regulatory threshold levels that would trigger a "Nuclear Facility" designation, This will allow us the opportunity to conduct low power operations and collect preliminary performance data prior to completing the rigorous DOE Nuclear Facility review process. The method we will use to develop limiting operational envelopes and for demonstrating threshold activities are not exceeded is presented. Calculational methodology for determining radionuclide inventory as a function of operating history is described. Building on work done at LANL, a Threshold Quantity Index (TQI) is defined that accounts for all calculated radionuclides and reasonable calculational uncertainties. The TQI is defined such that a value less than unity provides confidence that calculated activities do not exceed the regulatory threshold. The development of a TQI "budget " for desired operations is discussed. Operational limits will be set on peak and time-integrated beam current taking into account beam history, desired operational activities and the calculated TQI. TQI behavior as a function of beam-on-target for a hypothetical operating scenario is presented for a period of intermittent low power operations.