The criticality consequence analysis for pressurized water reactor (PWR) waste packages (WP)
(Civilian Radioactive Waste Management System [CRWMS] Management and Operating
Contractor [M&O] 1997) focused on results obtained by maximizing postulated rates of
reactivity insertion to assure no synergistic reactions could occur among waste packages from
hypothetical criticality events. Other variables potentially influencing the criticality
consequences were held constant during the above referenced analysis. One of those variables

The objective of this calculation is to document the Grand Gulf Unit 1 (GG1) reactivity calculations for sixteen critical statepoints in cycles 4 through 8. The GG1 reactor is a boiling water reactor (BWR) owned and operated by Entergy Operations Inc. The Commercial Reactor Criticality (CRC) evaluations support the development and validation of the neutronic models used for criticality analyses involving commercial spent nuclear fuel to be placed in a geologic repository. This calculation is performed as part of the evaluation in the CRC program.

Presented at the NEI Used Fuel Management Conference, St. Petersburg, FL, May 7-9, 2013

US policy for management of used nuclear fuel (UNF) and high level radioactive wastes (HLRW) is at a crossroads, and the success of new policy directions will depend in part on broad public acceptance and support. In this paper I provide an overview of the evidence concerning the beliefs and concerns of members of the American public regarding UNF and HLNW. I also characterize the evidence on American’s policy preferences for management of these materials.

The results of the MCNP criticality safety calculations described in this document are presented in Section 7.1. Based on the results presented attributes of the TAD canister-based systems that are important to ensuring their subcriticality are established. These attributes can be categorized according to the criticality control parameter that is impacted. Based on the categorization presented it is seen that moderation control is the underlying criticality control parameter for TAD canister-based systems containing CSNF with a maximum initial enrichment of 5 wt.% 235U/U.

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.

The purpose of this document is to establish waste acceptance technical requirements for the U.S. Department of Energy’s (DOE) Civilian Radioactive Waste Management System (CRWMS). These requirements and functions consist of two types: (a) internal CRWMS requirements derived from the Civilian Radioactive Waste Management System Requirements Document (CRD) (DOE 2007a) as illustrated in Figure 1, and (b) acceptance criteria imposed by the CRWMS on spent nuclear fuel (SNF) and high-level waste (HLW) delivered into the CRWMS.

The objective of this calculation is to evaluate the required minimum burnup as a function of initial boiling water reactor (BWR) assembly enrichment that would permit loading of spent nuclear fuel into the 44 BWR waste package configuration as provided in Attachment IV. This calculation is an application of the methodology presented in ''Disposal Criticality Analysis Methodology Topical Report'' (YMP 2003). The scope of this calculation covers a range of enrichments from 0 through 5.0 weight percent (wt%) U-235, and a burnup range of 0 through 40 GWd/MTU.

This new report from the National Research Council’s Nuclear and Radiation Studies Board (NRSB) and the Transportation Research Board reviews the risks and technical and societal concerns for the transport of spent nuclear fuel and high-level radioactive waste in the United States. Shipments are expected to increase as the U.S. Department of Energy opens a repository for spent fuel and high-level waste at Yucca Mountain, and the commercial nuclear industry considers constructing a facility in Utah for temporary storage of spent fuel from some of its nuclear waste plants.