This analysis is prepared by the Mined Geologic Disposal System (MGDS) Waste Package Development Department (WPDD) to provide an assessment of the present waste package design from a criticality risk standpoint. The specific objectives of this initial analysis are to:
1. Establish a process for determining the probability of waste package criticality as a function of time (in terms of a cumulative distribution function, probability distribution function, or expected number of criticalities in a specified time interval) for various waste package concepts;

The purpose of this document is to present the methodology to be used for development of the Subcritical Limit (SL) for post closure conditions for the Yucca Mountain repository. The SL is a value based on a set of benchmark criticality multiplier, keff> results that are outputs of the MCNP calculation method. This SL accounts for calculational biases and associated uncertainties resulting from the use of MCNP as the method of assessing kerr·

The purpose of the material degradation and release (MDR) model is to predict the fate of the waste package materials, specifically the retention or mobilization of the radionuclides and the neutron-absorbing material as a function of time after the breach of a waste package during the 10,000 years after repository closure. The output of this model is used directly to assess the potential for a criticality event inside the waste package due to the retention of the radionuclides combined with a loss of the neutron-absorbing material.

This report evaluates the potential for directly disposing of licensed commercial Dual Purpose
Canisters (DPCs) inside waste package overpacks without reopening. The evaluation considers
the principal features of the DPC designs that have been licensed by the Nuclear Regulatory
Commission (NRC) as these relate to the current designs of waste packages and as they relate to
disposability in the repository. Where DPC features appear to compromise future disposability,
those changes that would improve prospective disposability are identified.

The purpose of this analysis is to provide an initial radionuclide inventory (in grams per waste package) and associated uncertainty distributions for use in the Total System Performance Assessment for the License Application (TSPA-LA) in support of the license application for the repository at Yucca Mountain, Nevada. This document is intended for use in postclosure analysis only.

Recognizing that Idaho has a major strategic and economic interest in maintaining INL’s leadership role and in helping
the nuclear energy industry successfully meet these broader challenges, Idaho governor C.L. “Butch” Otter established
the Leadership in Nuclear Energy or “LINE” Commission in February 2012.

The Governor recognized that recent national developments in the nuclear energy sector will cause the State of Idaho to
face important choices in the future and that he needed to understand the best options available.

The objective of this siting study work is to support DOE in evaluating integrated advanced nuclear plant and ISFSI deployment options in the future. This study looks at several nuclear power plant growth scenarios that consider the locations of existing and planned commercial nuclear power plants integrated with the establishment of consolidated interim spent fuel storage installations (ISFSIs).

In order to decrease the risk of terrorism, it has been suggested that used nuclear fuel should be
moved to dry storage early, after five years cooling in the spent fuel pool. The Nuclear
Regulatory Commission (NRC) has reviewed this issue and issued a white paper stating that it
did not believe such a measure was justified in light of additional security measures implemented
at nuclear plants and the impacts associated with the early movement of used fuel into dry

The United States makes decisions regarding the domestic uses of nuclear energy and the nuclear fuel cycle primarily based economic considerations, domestic political constraints, and environmental impact concerns. Such factors influence U.S. foreign policy decisions as well, but foreign policy decisions are often more strongly determined by national security considerations, including concerns about nuclear weapons proliferation and nuclear terrorism.

To advance nuclear energy to meet future energy needs, ten countries—Argentina, Brazil, Canada, France, Japan, the Republic of Korea, the Republic of South Africa, Switzerland, the United Kingdom, and the United States—have agreed on a framework for international cooperation in research for a future generation of nuclear energy systems, known as Generation IV. The figure below gives an overview of the generations of nuclear energy systems. The first generation was advanced in the 1950s and 60s in the early prototype reactors.

The purpose of this report is to demonstrate that postclosure temperature limits can be met, and certain thermal characteristics of the postclosure thermal reference case can be preserved, with alternative thermal loading schemes. The analysis considers certain variations from the base case.waste stream, the predicted postclosure temperatures that develop within the rock mass due to these waste stream variations, and then compares these temperatures to postclosure temperature limits.

The purpose of these calculations is to characterize the criticality safety concerns for the storage of Fast Flux Test Facility (FFTF) nuclear fuel in a Department of Energy spent nuclear fuel (DOE SNF) canister in a co-disposal waste package. These results will be used to support the analysis that will be done to demonstrate concept viability related to use in the Monitored Geologic Repository (MGR) environment.

This analysis is prepared by the Mined Geologic Disposal System (MGDS) Waste Package Development Department (WPDD) to provide an assessment of the present waste package design from a criticality risk standpoint. The specific objectives of this initial analysis are to:
1. Establish a process for determining the probability of waste package criticality as a function of time (in terms of a cumulative distribution function, probability distribution function, or expected number of criticalities in a specified time interval) for various waste package concepts;

The Disposal Criticality Analysis Methodology Topical Reporta prescribes an approach to the methodology for performing postclosure criticality analyses within the monitored geologic repository at Yucca Mountain, Nevada. An essential component of the methodology is the Configuration Generator Model for In-Package Criticality that provides a tool to evaluate the probabilities of degraded configurations achieving a critical state.

The purpose of this report is to document and validate the external accumulation model that predicts accumulation of fissile materials in the invert, fractures and lithophysae in the rock beneath a degrading waste package containing spent nuclear fuel (SNF) in the monitored geologic repository at Yucca Mountain. (Lithophysae are hollow, bubblelike structures in the rock composed of concentric shells of finely crystalline alkali feldspar, quartz, and other materials (Bates and Jackson 1984 [DIRS 128109], p.

Disposal Criticality Analysis Methodology Topical Report describes a methodology for performing postclosure criticality analyses within the repository at Yucca Mountain, Nevada. An important component of the postclosure criticality analysis is the calculation of conservative isotopic concentrations for spent nuclear fuel. This report documents the isotopic calculation methodology. The isotopic calculation methodology is shown to be conservative based upon current data for pressurized water reactor and boiling water reactor spent nuclear fuel.

The almost limitless energy of the atom was first harnessed in the United States, as scientists proved the basic physics of nuclear fission in a rudimentary reactor built in the floor of a squash court at the University of Chicago in 1942, and then harnessed that proven energy source in the form of atomic weapons used to end World War II. Scientists who accomplished this feat moved quickly after World War II to harness that power for peaceful uses, focusing primarily on electricity generation for industry, commerce, and household use.

The purpose of this U.S. Department of Energy Nuclear Waste Fund Fee Adequacy Assessment
Report (Assessment) is to present an analysis of the adequacy of the fee being paid by nuclear
power utilities for the permanent disposal of their SNF and HLW by the United States
government.
This Assessment consists of six sections: Section 1 provides historical context and a comparison
to previous fee adequacy assessments; Section 2 describes the system, cost, income, and

This calculation demonstrates how uncertainties in half-life and branching fraction affect postclosure isotopic concentrations and the quantification of those effects in terms of reactivity.

The purpose of this calculation is to estimate the probability of criticality in a pressurized water reactor (PWR) uncanistered fuel waste package during the postclosure phase of the repository as a function of various waste package material, loading, and environmental parameters. Parameterization on the upper subcritical limit that is used to define the threshold for criticality will also be performed. The possibility of waste package misload due to human or equipment error during preclosure is also considered in estimating the postclosure criticality probability.