The purpose of this calculation is to simulate the processing of an incoming waste stream into waste packages, simulating the required aging as applicable, and the emplacement of the waste packages into the Yucca Mountain repository.

In July 1999, the U.S. Nuclear Regulatory Commission (NRC) Spent Fuel Project Office
(SFPO) issued Interim Staff Guidance 8 Revision 1 (ISG8R1) to provide recommendations for the use
of burnup credit in storage and transport of pressurized-water reactor (PWR) spent fuel. Subsequent to
the issuance of ISG8R1, the NRC Office of Regulatory Research (RES) has directed an effort to
investigate the technical basis for extending the criteria and recommendations of ISG8R1 to allow

The benefits of burnup credit and the technical issues associated with utilizing burnup credit in spent
nuclear fuel (SNF) casks have been studied in the United States for almost two decades. The issuance of the
U.S. Nuclear Regulatory Commission (NRC) staff guidance for actinide-only burnup credit in 2002 was a
significant step toward providing a regulatory framework for using burnup credit in transport casks. However,
adherence to the current regulatory guidance (e.g., limit credit to actinides) enables only about 30% of the existing

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<p><span style="font-size: 12.000000pt; font-family: 'TimesNewRomanPSMT'">This report fulfills the M1 milestone M11UF041401, &ldquo;Storage R&amp;D Opportunities Report&rdquo; under Work Package Number FTPN11UF0414. </span></p>