Presentation made at International Conference on The Management of Spent Nuclear Fuel from Nuclear Power Reactors, An Integrated approach to the Back-End of the Fuel Cycle (IAEA-CN-226). The purpose of the conference was to highlight the importance of an integrated long-term approach to the management of spent fuel from nuclear power reactors.

This analysis provides information necessary for total system performance assessment (TSPA) for the license application (LA) to include the excess U.S. Department of Energy (DOE) plutonium in the form of mixed oxide (MOX) spent nuclear fuel and lanthanide borosilicate (LaBS) glass. This information includes the additional radionuclide inventory due to MOX spent nuclear fuel and LaBS glass and the analysis that shows that the TSPA models for commercial spent nuclear fuel (CSNF) and high-level waste (HLW) degradation are appropriate for MOX spent nuclear fuel and LaBS glass, respectively.

The purpose of this calculation is to develop an estimate of the isotopic content as a function of time for mixed oxide (MOX) spent nuclear fuel (SNF) assemblies in a Westinghouse pressurized water reactor (PWR). These data will be used as source data for criticality, thermal, and radiation shielding evaluations of waste package (WP) designs for MOX assemblies in the Monitored Geologic Repository (MGR).

As part of the plutonium waste form development and down-select process, repository analyses have been conducted to evaluate the long-term performance of these forms for repository acceptance. Intact and degraded mode criticality analysis of the mixed oxide (MOX) spent fuel is presented in Volume I, while Volume II presents the evaluations of the waste form containing plutonium immobilized in a ceramic matrix.

Taking into account of the loss of reactivity of fuels at the end of their irradiation is known under the
term burnup credit (BUC). It is a question of dimensioning in a less penalizing way the devices of transport,
storage or of processing with respect to the risk of criticality. In the context of nuclear criticality safety a better
realism cannot be obtained at the price of conservatism. As a result the regulator requires measurements make it
possible to validate the adequacy between real fuels and the design assumptions. The sophistication of the

This report presents results from a parametric study of equilibrium fuel cycle costs for a closed fuel cycle with multi-recycling of plutonium in fast reactors (FRs) compared to an open, once-through fuel cycle using PWRs. The study examines the impact on fuel cycle costs from changes in the unit costs of uranium, advanced PUREX reprocessing of discharged uranium dioxide (UO2) fuel and fast-reactor mixed-oxide (FR-MOX) fuel, and FR-MOX fuel fabrication.

Expanding interest in nuclear power and advanced fuel cycles indicate that use of mixed-oxide (MOX) fuel in the current and new U.S. reactor fleet could become an option for utilities in the coming decades. In light of this renewed interest, EPRI has reviewed the substantial knowledge base on MOX fuel irradiation in light water reactors (LWRs). The goal was to evaluate the technical feasibility of MOX fuel use in the U.S. reactor fleet for both existing and advanced LWR designs (Generation III/III+).

Within the context of long-term waste management and sustainable nuclear fuel supply, there continue to be discussions regarding whether the United States should consider recycling of light-water reactor (LWR) spent nuclear fuel (SNF) for the current fleet of U.S. LWRs. This report presents a parametric study of equilibrium fuel cycle costs for an open fuel cycle without plutonium recycling (once-through) and with plutonium recycling (single-recycling using mixed-oxide, or MOX, fuel), assuming an all-pressurized water reactor (PWR) fleet.

As part of the plutonium waste form development and down-select process, repository analyses have been conducted to evaluate the long-term performance of these forms for repository acceptance. Intact and degraded mode criticality analysis of the mixed oxide (MOX) spent fuel is presented in Volume I, while Volume II presents the evaluations of the waste form containing plutonium immobilized in a ceramic matrix.

The purpose of this calculation is to perform a parametric study to determine the effects of fission product leaching, assembly collapse, and iron oxide loss (Me203) on the reactivity of a waste package (WP) containing mixed oxide (MOX) spent nuclear fuel (SNF). Previous calculations (CRWMS M&O 1998a) have shown that the criticality control features of the WP are adequate to prevent criticality of a flooded WP for all the enrichment/ burnup pairs expected for the MOX SNF.

The purpose of this calculation is to perform a parametric study to determine the effects of fission product leaching, assembly collapse, and iron oxide loss on the reactivity of a waste package containing mixed oxide spent nuclear fuel. Previous calculations (CRWMS M&O 1998a) have shown that the criticality control features of the waste package are adequate to prevent criticality of a flooded WP for all the enrichment/burnup pairs expected for the MOX SNF.

This paper presents an assessment of the benefits for extended burnup credit in transporting
pressurized-water-reactor (PWR) spent nuclear fuel (SNF) in the United States. A prototypic 32-
assembly cask and the current regulatory guidance were used as bases for this assessment. By
comparing recently released PWR discharge data with actinide-only-based loading curves, this
evaluation shows that additional negative reactivity (through either increased credit for fuel burnup or

The purpose of this calculation is to perform criticality evaluations for mixed oxide spent nuclear fuel (MOX SNF) in 12 and 21 Pressurized Water Reactor (PWR) waste packages (WPs) for both intact and degraded configurations.
The MOX assembly design considered in previous studies on Pu disposition in commercial reactors is based on the Westinghouse (W) 17x17 Vantage 5 assembly (Ref. 7.2). Depletion analyses of four Pu enrichment and burnup (expressed as gigawatt days/metric ton heavy metal; GWd/MTHM) combinations were performed in Reference 7.4. These are:

The objective of this calculation is to perform additional degraded mode criticality evaluations of the Department of Energy's (DOE) Fast Flux Test Facility (FFTF) Spent Nuclear Fuel (SNF) codisposed in a 5-Defense High-Level Waste (5-DHLW) Waste Package (WP). The scope of this calculation is limited to the most reactive degraded configurations of the codisposal WP with an almost intact Ident-69 container (breached and flooded but otherwise non-degraded) containing intact FFTF SNF pins.

The purpose of this calculation is to evaluate the transient behavior and consequences of a worst- case criticality event involving intact pressurized water reactor (PWR) mixed-oxide (MOX) spent nuclear fuel (SNF) in a degraded basket configuration inside a 21 PWR waste package (WP). This calculation will provide information necessary for demonstrating that the consequences of a worst-case criticality event involving intact PWR MOX SNF are insignificant in their effect on the overall radioisotopic inventory and on the integrity of the repository.

Following the proposals for nuclear fuel assurance of International Atomic Energy
Agency (IAEA) Director General Mohamed ElBaradei, former Russian President Vladimir V.
Putin, and U.S. President George W. Bush, joint committees of the Russian Academy of
Sciences (RAS) and the U.S. National Academies (NAS) were formed to address these and other
fuel assurance concepts and their links to nonproliferation goals. The joint committees also
addressed many technology issues relating to the fuel assurance concepts. This report provides

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

This analysis is prepared by the Mined Geologic Disposal System (MGDS) Waste Package Development Department (WPDD) to compare the criticality potential of Westinghouse 17x17 mixed oxide (MOX) PWR fuel with the Design Basis spent nuclear fuel (SNF) analyzed previously (Ref. 5.1, 5.2). The basis of comparison will be the conceptual design Multi- Purpose Canister (MPC) PWR waste package concepts.

There are more than 250 forms of U.S. Department of Energy (DOE)-owned spent nuclear fuel (SNF). Due to the variety of the spent nuclear fuel, the National Spent Nuclear Fuel Program (NSNFP) has designated nine representative fuel groups for disposal criticality analyses based on fuel matrix, primary fissile isotope, and enrichment. Fast Flux Test Facility (FFTF) fuel has been designated as the representative fuel for the mixed-oxide (MOX) fuel group which is a mixture of uranium and plutonium oxides.

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

Ever since the 1950s, plutonium, used in fas reactors, has been seen as the key to unlocking the vast energy resource contained in the the world's uranium reserves. However, the reductions in expected nuclear reactor installation rates, combined with discovery of additional uranium, have led to a lengthening in the perceived time interval before fast reactors, the most effective users of plutonium, will make large demands on plutonium supplies. THere are several options concerning its use or storage in the meantime.