November 9, 2005 Thomas Hill, NSNFP DOE SNF Canister Planned Activities.
Post on 01-Jan-2016
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Limited Canister Analysis Planned
• Canister basket design
• Canister dynamic material properties verifications
• Transportation accident response
Canister Basket Development
• Canister defined by Preliminary Specification and Idaho Dry Storage Project design
• Concept for canister baskets provided in criticality analysis, except for MCOs.
• No functional or performance requirements available for canister baskets
• General configurations of baskets used in a number of reports
• NSNFP preparing a preliminary specification to guide basket design efforts.
DOE Canister Analysis Status
• The DOE canisters include both the Multi-Canister Overpacks (MCOs) and the standardized DOE SNF canisters
• Full-scale drop tests have demonstrated that these canisters (at ambient temperatures) maintain containment (no-breach) after accidental drop events
• Elastic-plastic analyses of these drop tests were performed (with an assumed 1.2 factored material true stress-strain curve increase) in order to demonstrate an acceptable analysis methodology
DOE Canister Analysis Status – cont’d
• Analysis would cover other canister conditions, lower or higher temperatures, different internals, material aging issues, etc.
• Canister deformations from very high strain levels require justification of material properties used in analysis predictions (ASME B&PV Code, Section III, Appendix F)
• Material impact testing efforts justify the final material models used in analyses
Material Definition Needs
• Loads associated with accidental drop events are typically design governing for canisters
• The better the elastic-plastic material definition is, the better the analytical predictions
• How much increase really exists is needed, since little information is readily available that addresses materials of interest at strain rates and temperatures of interest
Approach
• The approach is to use the INL developed Impact Testing Machine or ITM
• It is a drop weight device with weights as large as 1600 pounds and drop heights up to 13 feet
• A true impact is achieved instead of a hydraulic-based system that imposes strain rates only
Material Impact Testing Goals
• Quantify the increase (over that obtained from quasi-static tensile testing) of the canister material (304L and 316L stainless steels) true stress-strain curves
• Examine if cracks or tearing is initiated
Future Dynamic Testing Efforts
• Address adequate range of strain rates
• Incorporate temperature effects
• Gain weld and base metal response insights
• Determine flaw responses at varying strain rates
• Investigate bending and shear responses
Transportation Accident Evaluations
• To gain insights into the structural response of MCOs to hypothetical transportation accidents
• Identify potential MCO transportation concerns using analytical techniques
• Identify corrective actions for MCO transportation package
Transportation Package Design
• Transportation package design / response assumed but based on existing industry product (Hi-Star 100)
• Package has response of 60Gs maximum in any drop orientation
Analyses To Be Performed• Shielding calculations assess basic shielding
needs (MCO and standardized canisters in existing casks)
• Thermal calculations determine MCO material conditions
• Transportation accident analyses to be made to estimate the structural responses
– Ability of MCOs to maintain containment after hypothetical accident events
– Ability of MCOs to be retrieved from transportation package after drop event
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