EXTENDED DRY STORAGE AND TRANSPORTATION: MODEL FOR EVALUATING VACUUM DRYING ADEQUACY

摘要

This paper identifies a method for assessing potential consequences from residual water following incomplete drying of spent nuclear fuel (SNF), cladding and internal components in a dry storage cask. The assessment uses a time-dependent integrated model that accounts for residual water, temperature, relative humidity, and radiolysis kinetics to decompose water into oxygen and hydrogen. Various abstracted models are presented based on literature information for cladding oxidation, SNF oxidation/hydration, cladding splitting due to SNF swelling, relative humidity threshold for aqueous corrosion, and radiolysis kinetics. Each discrete time interval of the integrated model addresses degradation of cladding, SNF and other cask internal components. Possible changes to flammability conditions and criticality margin are also addressed. Uncertainties associated with data and model abstractions are addressed in the integrated model. This paper presents interim progress for model abstraction, model integration, and uncertainty assessments. Quantitative results will be presented in the future.