Further to the development of a model analysis framework suitable for calibration and validation of complex multivariate multiphysics models detailed in [1], this report presents an approach to data collection and characterization which can work in parallel with the above-mentioned model analysis framework and support the calibration and validation of the case-study subcooled flow boiling model presented in [1].This work presents a step forward in the development and realization of the "CIPS Validation Data Plan" [2][3] at the Consortium for Advanced Simulation of LWRs (CASL) to enable quantitative assessment of the CASL modeling of CrudInduced Power Shift (CIPS) phenomenon, in particular, and the CASL advanced predictive capabilities, in general.Advanced modeling of LWR systems normally involves a range of physicchemical models describing multiple interacting phenomena, such as thermal hydraulics, reactor physics, coolant chemistry, etc., which are usually constrained by the lack of data suitable for model validation and calibration. The necessary employment of different modeling approaches in the advanced LWR modeling practice further complicates the situation, since each modeling approach has a unique requirement of validation data. The development and validation of closure model of wall heat transfer process employed in the subcooled flow boiling modeling, for instance, may require data of microscopic physics, i.e. wall heat flux partitioning, bubble nucleation, growth and detachment dynamics, etc.[4], which can hardly be obtained for reactor-prototypical conditions.Although the model analysis framework proposed in [1] is designed to be robust enough to deal with a wide range of measurement data of different quality and availability, a strategy for data collection, data validation and data characterization is still needed which has been detailed in [3]. This work presents an implementation of that strategy for a case-study calibration/validation of a subcooled flow boiling model. The lesson learnt and implication to CIPS modeling and the overall CASL VUQ effort will also be discussed.
EXECUTIVE SUMMARYThis milestone supports a case study on development, testing and application of a strategy, methods and associated infrastructure for validation data support that enables assessment of CASL-developed predictive capability for Crud-Induced Power Shift (CIPS) challenge problem as formulated in a previous report for CASL.VUQ.VVDA.P4.02 [3]. Subcooled flow boiling (SFB) prediction is selected as a capability for which data collection, characterization and integration (model calibration) be performed, with the objective to develop recommendations on a CASL-wide Validation Data Process.This milestone focuses on quantification of data needs, data collection and characterization, preparing the ground for the SFB model calibration and validation. The selected test case (simulation of subcooled flow boiling) is an important capability for CIPS prediction, whose development has been hampered by validation data ch...