This “Technical Evaluation Report on the Content of the U.S. Department of Energy’s Yucca Mountain License Application; Postclosure Volume: Repository Safety After Permanent Closure” (TER Postclosure Volume) presents information on the NRC staff’s review of DOE’s Safety Analysis Report (SAR), provided on June 3, 2008, as updated by DOE on February 19, 2009. The NRC staff also reviewed information DOE provided in response to NRC staff’s requests for additional information and other information that DOE provided related to the SAR.

The success of the Civilian Radioactive Waste Management Program of the U.S.
Department of Energy (DOE) is critical to U.S. ability to manage and dispose of
nuclear waste safely--and to the reestablishment of confidence in the nuclear energy
option in the United States. The program must conform with all applicable standards
and, in fact, set the example for a national policy on the safe disposal of radioactive
waste.
The Secretary of Energy has recently completed an extensive review of the

By the end of this century, the United States plans to begin operating the first geologic repository for the permanent disposal of commercial spent nuclear fuel and high-level radioactive Waste. Public Law 97-425, the Nuclear waste Policy Act of 1982 (the Act), specifies the process for selecting a repository site, and constructing, operating, closing, and decommissioning the repository.

This report presents the results of computer code benchmark simulations against spent fuel radiochemical assay
measurements from the Kansai Electric Ltd. Takahama-3 reactor published by the Japan Atomic Energy
Research Institute. Takahama-3 is a pressurized-water reactor that operates with a 17 × 17 fuel-assembly design.
Spent fuel samples were obtained from assemblies operated for 2 and 3 cycles and achieved a maximum burnup
of 47 GWd/MTU. Radiochemical analyses were performed on two rods having an initial enrichment of

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.

Spent Fuel Project Office, Interim Staff Guidance - 8, Revision 1

The report describes the final results of the Phase IIIB Benchmark conducted by the
Expert Group on Burnup Credit Criticality Safety under the auspices of the Nuclear Energy
Agency (NEA) of the Organization for Economic Cooperation and Development (OECD).
The Benchmark was intended to compare the predictability of current computer code and
data library combinations for the atomic number densities of an irradiated BWR fuel
assembly model. The fuel assembly was irradiated under specific power of 25.6 MW/tHM

An Account of the Programs of Federal Agencies and Events That Have Led to the Selection of a Potential Site for a Geologic Repository for High-Level Radioactive Waste

The effective termination of the Yucca Mountain program by the U.S. Administration in 2009
has further delayed the construction and operation of a permanent disposal facility for used fuel
and high level radioactive waste (HLW) in the United States. In concert with this decision, the
President directed the Energy Secretary to establish the Blue Ribbon Commission on America’s
Nuclear Future to review and provide recommendations on options for managing used fuel and

Since the mid-1980s, a significant number of studies have been directed at understanding the phenomena and
parameters important to implementation of burnup credit in out-of-reactor applications involving pressurizedwater-
reactor (PWR) spent fuel. The efforts directed at burnup credit involving boiling-water-reactor (BWR)
spent fuel have been more limited. This paper reviews the knowledge and experience gained from work
performed in the United States and other countries in the study of burnup credit. Relevant physics and analysis

This report has been prepared to review relevant background information and provide technical discussion that will help initiate a PIRT (Phenomena Identification and Ranking Tables) process for use of burnup credit in light-water reactor (LWR) spent fuel storage and transport cask applications. The PIRT process will be used by the NRC Office of Nuclear Regulatory Research to help prioritize and guide a coordinated program of research and as a means to obtain input/feedback from industry and other interested parties.

In January 1999, the U.S. Department of Energy (DOE)/Office of Civilian Radioactive
Waste Management (OCRWM) submitted the Disposal Criticality Analysis Methodology
Topical Report, Revision 0 (TR) to the U.S. Nuclear Regulatory Commission (NRC) for
review and approval. The TR presents an overall approach for consideration of postclosure
disposal criticality of commercial and defense high-level waste to be placed at
the proposed Yucca Mountain site. During the course of the review and interactions

The fundamental objective of this topical report is to present the planned risk-informed disposal criticality analysis methodology to the NRC to seek acceptance that the principles of the methodology and the planned approach to validating the methodology are sound. The design parameters and environmental assumptions within which the waste forms will reside are currently not fully established and will vary with the detailed waste package design, engineered barrier design, repository design, and repository layout.

101. These Regulations establish standards of safety which provide an
acceptable level of control of the radiation, criticality and thermal hazards to
persons, property and the environment that are associated with the transport of
radioactive material. These Regulations utilize the principles set forth in both
the “Radiation Protection and the Safety of Radiation Sources”, Safety Series
No. 120 [1] and the “International Basic Safety Standards for Protection
against Ionizing Radiation and for the Safety of Radiation Sources”, Safety

This standard provides criteria for accounting for reactivity effects of fuel irradiation and radioactive decay in criticality safety control of storage, transportation, and disposal of commercial LWR UO2 fuel assemblies.

This standard assumes the fuel and any fixed burnable absorbers are contained in an intact assembly. Additional considerations could be necessary for fuel assemblies that have been disassembled, consolidated, damaged, or reconfigured in any manner.

The Interim Staff Guidance on burnup credit (ISG-8) for spent fuel in storage and transportation casks, issued by the Nuclear Regulatory Commission’s Spent Fuel Project Office, recommends a burnup measurement for each assembly to confirm the reactor record and compliance with the assembly burnup value used for loading acceptance. This recommendation is intended to prevent unauthorized loading (misloading) of assemblies due to inaccuracies in reactor burnup records and/or improper assembly identification, thereby ensuring that the appropriate subcritical margin is maintained.

This Integrated Issue Resolution Status Report provides background information about the status of prelicensing interactions between the U.S. Department of Energy (DOE) and the U.S. Nuclear Regulatory Commission (NRC) concerning a potential high-level waste geologic repository at Yucca Mountain, Nevada. The NRC staff has, for many years, engaged in prelicensing interactions with DOE and various stakeholders.

Present regulatory practices provide as much burnup credit flexibility as can be currently
expected. Further progress is achievable by incorporating the negative reactivity effects of a
subset of neutron-absorbing fission-product isotopes, and by optimizing the procedural approach
for establishing the burnup characteristics of the spent fuel to be loaded in burnup-creditdesigned
storage and transportation systems. This report describes progress toward developing a

Although there are many reactor system benchmarks in the literature, they mostly
concentrate on the reactor system in isolation with only a few considering the fuel cycle.
However, there is currently increased emphasis on the performance of reactor systems
linked to their associated fuel cycle (Generation-IV for example). The published
international benchmark studies which relate to burn-up depletion calculations are
restricted to specific aspects of the fuel cycle:

This report proposes and documents a computational benchmark for the estimation of the
additional reactivity margin available in spent nuclear fuel (SNF) from fission products and minor
actinides in a burnup-credit storage/transport environment, relative to SNF compositions
containing only the major actinides. The benchmark problem/configuration is a generic burnupcredit
cask designed to hold 68 boiling water reactor (BWR) spent nuclear fuel assemblies. The
purpose of this computational benchmark is to provide a reference configuration for the