b'A Critical Review of High Burnup Fuel Fragmentation, Relocation,and Dispersal under Loss-of-Coolant-Accident ConditionsPrincipal Investigator: Nathan Capps (Oak Ridge National Laboratory)Team Members/ Collaborators: Colby Jensen (Idaho National Laboratory), Fabiola Cappia (Idaho National Laboratory), Jason Harp (Oak Ridge National Laboratory), Kurt Terrani (Oak Ridge National Laboratory), Nicolas Woolstenhulme (Idaho National Laboratory), and Daniel Wachs (Idaho National Laboratory)The content of thisE xperimental data produced byHowever, there is a significant data fuel fragmentation testing ofgap connecting research to commer-manuscript provideshigh burnup fuel is limitedcial application. Major identified data a clear path forin the literature, and collection ofgaps consist of (1) a comprehensive connecting testingnew data limited by both the timeunderstanding of pretransient fuel and data acquisition torequired to irradiate commercialrod conditions (fuel temperature, fuel commercial applicationfuels to relevant burnup as well asstress, rod internal pressures, micro-by providing concretethe cost. This data is essential tostructure, etc. (see Figure 1). The first means for filling datafacilitate ongoing efforts to extendfigure provides a snapshot at the end gaps and prioritizedrod average burnup to ~75 GWd/tUof a cycle for a core containing high testing regimes. in the coming years. The uncertain- burnup fuel. The figure highlights ties and caveats inherent to complexthat there are at minimum two hot cell testing are present in thedifferent operating regimes (center existing data, but not always identi- of the core and core periphery) fied. Advanced Fuels Campaign (AFC)that may impact end of life fuel rod research staff therefore performedconditions. Additional data gaps are a comprehensive review of all the(2) definition of prototypic loss-of-publicly available data related tocoolant accident conditions (heating high burnup fuel fragmentation,rate, fuel temperatures, fuel stress), relocation, and dispersal. The reportand (3) identification of the differ-summarizes the loss of coolant acci- ences between nuclear and electrical dent (LOCA) integral test, separateintegral loss-of-coolant accident tests.effects heating test, and detailedFigure 2 is an example of fragmented microstructure analysis examinations. fuel from the Severe Accident Test Project Description: Station (SATS) facility at ORNL. SATS The purpose of this review is touses an electrically heated furnace perform a critical, holistic assessmentto heat sample up from ~330oC, of fuel fragmentation, relocation,whereas fuel in a commercial and dispersal under loss-of-coolantreactor will be at power prior to the conditions to identify data gaps in thetransient. Halden data suggest fuel experimental data base. Phenomenaoperating at power prior to the tran-have been identified and well definedsient may experience less fragmenta-through the various testing programs,tion than observed in an electrically and general agreement regarding theheated furnace. Finally, connecting governing parameters (temperature,fuel rod performance (cladding burnup, heating rate, cladding defor- ballooning, burst opening, potential mation, etc.) has been established.relocation, fragmentation suscep-80 2021|AFC ACCOMPLISHMENTS'