Feasibility assessment of burnup credit in the criticality analysis of shipping casks with boiling water reactor spent fuel

Technical Report · Thu Aug 01 04:00:00 EDT 1991

DOI:https://doi.org/10.2172/6243609· OSTI ID:6243609

Broadhead, B L

Considerable interest in the allowance of reactivity credit for the exposure history of power reactor fuel currently exists. This burnup credit'' issue has the potential to greatly reduce risk and cost when applied to the design and certification of spent fuel casks used for transportation and storage. Recently, analyses have demonstrated the technical feasibility and estimated the risk and economic incentives for allowing burnup credit in pressurized water reactor (PWR) spent fuel shipping cask applications. This report summarizes the extension of the previous PWR technical feasibility assessment to boiling water reactor (BWR) fuel. This feasibility analysis aims to apply simple methods that adequately characterize the time-dependent isotopic compositions of typical BWR fuel. An initial analysis objective was to identify a simple and reliable method for characterizing BWR spent fuel. Two different aspects of fuel characterization were considered:l first, the generation of burn- up dependent material interaction probabilities; second, the prediction of material inventories over time (depletion). After characterizing the spent fuel at various stages of exposure and decay, three dimensional (3-D) models for an infinite array of assemblies and, in several cases, infinite arrays of assemblies in a typical shipping cask basket were analyzed. Results for assemblies without a basket provide reactivity control requirements as a function of burnup and decay, while results including the basket allow assessment of typical basket configurations to provide sufficient reactivity control for spent BWR fuel. Resulting basket worths and reactivity trends over time are then evaluated to determine whether burnup credit is needed and feasible in BWR applications.

• Research Organization: Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6243609
• Report Number(s): ORNL/CSD/TM-268; TTC--1033; ON: DE92002402
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210100* -- Power Reactors
Nonbreeding
Light-Water Moderated
Boiling Water Cooled
BURNUP
BWR TYPE REACTORS
CASKS
CONTAINERS
CRITICALITY
ENERGY SOURCES
ENRICHED URANIUM REACTORS
FEASIBILITY STUDIES
FUEL ELEMENTS
FUELS
MATERIALS
NUCLEAR FUELS
POWER DENSITY
POWER REACTORS
REACTIVITY
REACTOR COMPONENTS
REACTOR MATERIALS
REACTORS
SPENT FUEL CASKS
SPENT FUELS
THERMAL REACTORS
WATER COOLED REACTORS
WATER MODERATED REACTORS