Spent Fuel Project Office Interim Staff Guidance - 8

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

This paper describes the lessons learned from the U.S. Department of Energy (DOE) transportation of
125 DOE-owned commercial spent nuclear fuel (SNF) assemblies by railroad from the West Valley Demonstration
Project to the Idaho National Engineering and Environmental Laboratory (INEEL). On July 17, 2003, DOE made
the largest single shipment of commercial SNF in the history of the United States. This was a highly visible and
political shipment that used two specially designed Type B transportation and storage casks. This paper describes

This research examines the practice of equating the reactivity of spent fuel to that of fresh fuel for the purpose of performing burnup credit criticality safety analyses for PWR spent fuel pool (SFP) storage conditions. The investigation consists of comparing kf estimates based on reactivity "equivalent" fresh fuel enrichment (REFFE) to kl estimates using the actual spent fuel isotopics.

This report presents a best-estimate probabilistic risk assessment (PRA) to quantify the frequency of criticality accidents during railroad transportation of spent nuclear fuel casks. The assessment is of sufficient detail to enable full scrutiny of the model logic and the basis for each quantitative parameter contributing to criticality accident scenario frequencies. The report takes into account the results of a 2007 peer review of the initial version of this probabilistic risk assessment, which was published as EPRI Technical Report 1013449 in December 2006.

STARBUCS is a new prototypic analysis sequence for performing automated criticality safety analyses of spent fuel systems employing burnup credit. A depletion analysis calculation for each of the burnup-dependent regions of a spent fuel assembly, or other system containing spent fuel, is performed using the ORIGEN-ARP sequence of SCALE. The spent fuel compositions are then used to generate resonance self-shielded cross sections for each region of the problem, which are applied in a three-dimensional criticality safety calculation using the KENO V.a code.

Spent Fuel Project Office, Interim Staff Guidance - 8, Revision 2 - Burnup Credit in the Criticality Safety Analyses of PWR Spent Fuel in Transport
and Storage Casks

This report has been prepared to qualitatively assess the amount of burnup credit (reactivity margin) provided by ISG-8 compared to that provided by the burnup credit methodology developed and currently applied in France. For the purposes of this study, the methods proposed in the DOE Topical Report have been applied to the ISG-8 framework since this methodology (or one similar to it) is likely to form the basis of initial cask licensing applications employing limited burnup credit in the United States.

There have been roughly 2,600 shipments of commercial spent fuel in this country over the past three decades or so. Although this is not an enormous volume by European standards, it is nevertheless significant. These shipments fall into two general categories: individual and "campaign."
There have been a number of individual shipments where lead test assembly fuel was shipped from a reactor to a laboratory for examination. This is an important part of reactor fuel development.

With the Department of Energy’s (DOE) recent submittal of a license application to the U.S. Nuclear Regulatory Commission, the development of Yucca Mountain, Nevada, as a national nuclear waste repository moves one step closer to reality. An operating site at Yucca Mountain could receive between 38-106 rail shipments and 53-89 truck shipments annually over a period of 50 years.