The purpose of this report is to develop and analyze the Engineered Barrier System (EBS) Radionuclide Transport Abstraction Model, consistent with Level I and Level II model validation, as identified in Technical Work Plan for: Near-Field Environment: Engineered Barrier System: Radionuclide Transport Abstraction Model Report (BSC 2006 [DIRS 177739]). The EBS Radionuclide Transport Abstraction (or RTA) is the conceptual model used in the Total System Performance Assessment (TSPA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ).

The U.S. Nuclear Regulatory Commission (NRC) is evaluating the safety and security of spent nuclear fuel (SNF) stored in dry casks for extended time periods before transportation to a location where the SNF is further processed or permanently disposed.

This report evaluates the radiological impacts during postulated accidents associated with the
transportation of spent nuclear fuel to the proposed Yucca Mountain repository, using the
RADTRAN 5.5 computer code developed by Sandia National Laboratories. RADTRAN 5.5 can
be applied to estimate the risks associated both with incident-free transportation of radioactive
materials as well as with accidents that may be assumed to occur during transportation. Incidentfree
transportation risks for transport of spent nuclear fuel to Yucca Mountain were evaluated in