The "Summary Report of SNF Isotopic Comparisons for the Disposal Criticality Analysis Methodology" contains a summary of the analyses that compare SNF measured isotopic concentrations (radiochemical assays) to calculated SNF isotop~c concentrations (SAS2H module ·orScale4.3). The results of these analyses are used to support the validation of the isotopic models for spent commercial light water reactor (LWR) fuel.

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.

Approximately 54,000 tons of spent nuclear fuel are stored at operating nuclear power plants and several decommissioned power plants throughout the country. Spent fuel storage at these sites was never intended to be permanent. The current Federal plan is to place the fuel in a repository for permanent disposal in Nevada at Yucca Mountain.

A methodology for performing and applying nuclear criticality safety calculations, for PWR spent nuclear fuel (SNF) packages with actinide-only burnup credit, is described. The changes in the U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242, and Am-241 concentration with burnup are used in burnup credit criticality analyses. No credit for fission product neutron absorbers is taken. The methodology consists of five major steps. (1) Validate a computer code system to calculate isotopic concentrations of SNF created during burnup in the reactor core and subsequent decay.

A methodology for performing and applying nuclear criticality safety calculations, for PWR spent nuclear fuel (SNF) packages with actinide-only burnup credit, is described. The changes in the U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242, and Am-241 concentration with burnup are used in burnup credit criticality analyses. No credit for fission product neutron absorbers is taken. The methodology consists of five major steps. (1) Validate a computer code system to calculate isotopic concentrations of SNF created during burnup in the reactor core and subsequent decay.

The issue of interim storage of used (spent)1 fuel is dependent on a number of key factors, some
of which are not known at this time but are the subject of this study. The first is whether or not
the Yucca Mountain Project continues or is cancelled such that it may be able to receive spent
fuel from existing and decommissioned nuclear power stations. The second is whether the United
States will pursue a policy of reprocessing and recycling nuclear fuel. The reprocessing and

This report presents the results of a critical review of the technological challenges to the growth of nuclear energy, emerging advanced technologies that would have to be deployed, and fuel cycle strategies that could conceivably involve interim storage, plutonium recycling in thermal and fast reactors, reprocessed uranium recycling, and transmutation of minor actinide elements and fission products before eventual disposal of residual wastes.

As nuclear power plants began to run out of storage capacity in spent nuclear fuel (SNF) storage pools, many nuclear operating companies added higher density pool storage racks to increase pool capacity. Most nuclear power plant storage pools have been re-racked one or more times. As many spent fuel storage pools were re-racked to the maximum extent possible, nuclear operating companies began to employ interim dry storage technologies to store SNF in certified casks and canister-based systems outside of the storage pool in independent spent fuel storage installations (ISFSIs).

The Department of Energy (DOE) is studying a site at Yucca Mountain, Nevada, for a
permanent underground repository for highly radioactive spent fuel from nuclear reactors,
but delays have pushed back the facility’s opening date to 2010 at the earliest. In the
meantime, spent fuel is accumulating at U.S. nuclear plant sites at the rate of about 2,000
metric tons per year. Major options for managing those growing quantities of nuclear spent
fuel include continued storage at reactors, construction of a DOE interim storage site near

The Nuclear Waste Policy Act of 1982, as amended, established a statutory basis
for managing the nation’s civilian (or commercially produced) spent nuclear
fuel. The law established a process for siting, developing, licensing, and constructing
an underground repository for the permanent disposal of that waste.
Utilities were given the primary responsibility for storing spent fuel until it is
accepted by the Department of Energy (DOE) for disposal at a repository —
originally expected to begin operating in 1998. Since then, however, the repository

Approximately 54,000 tons of spent nuclear fuel are stored at operating nuclear power plants and several decommissioned power plants throughout the country. Spent fuel storage at these sites was never intended to be permanent. The current Federal plan is to place the fuel in a repository for permanent disposal in Nevada at Yucca Mountain.

The purpose of this study is to assist decision makers in evaluating the centralized interim
storage option. We explore the economics of centralized interim storage under a wide variety of
circumstances. We look at how a commitment to move forward with centralized interim storage
today could evolve over time. And, we evaluate the costs of reversing a commitment toward
centralized storage if it turns out that such a decision is later considered a mistake. We have not

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.

The issue of interim storage of used (spent)1 fuel is dependent on a number of key factors, some
of which are not known at this time but are the subject of this study. The first is whether or not
the Yucca Mountain Project continues or is cancelled such that it may be able to receive spent
fuel from existing and decommissioned nuclear power stations. The second is whether the United
States will pursue a policy of reprocessing and recycling nuclear fuel. The reprocessing and

The management of spent nuclear fuel (SNF) and defense high level waste (HLW) is a complex sociotechnical
systems challenge. Coordinated, reliable, and safe performance will be required over very long
periods of time within evolving social and technical contexts. To accomplish these goals, a waste
management system will involve a host of facilities for interim storage and longterm disposal, a
transportation infrastructure, and research and development centers. The complexity of SNF and HLW

About 20,000 metric tons of spent, or used, nuclear
fuel have accumulated since the beginning of commercial
nuclear power prbduction in the United States. At the end
of the currently licensed period of all existing nuclear power
plants and those under construction, the amount of spent
nuclear fuel is expected to total 87,000 metric tons.
Thus far, practically all of the spent nuclear fuel is
stored in water-filled pools at reactor sites. However, space
does not exist in the pools to store all the spent fuel expected