GCFR 1/15-Scale PCRV Steam Generator Cavity Closure Half-Thickness Model Test

摘要

Oak Ridge National Laboratory is conducting structural response tests of the prestressed concrete reactor vessel (PCRV) closures for the 300-MW(e) GCFR demonstration power plant. The report describes the second in a series of tests of small-scale closure plug models. The model represents a redesign of the steam generator cavity closure plug to a thickness of one-half that of the original model. The primary objective was to demonstrate structural performance and ultimate load capacity of the closure plug. Secondary objectives included obtaining data on crack development and propagation and mode of failure of the composite structure. After ten pressurization cycles from zero load to the maximum cavity pressure (MCP) of 10.08 MPa (1462 psig), the model was pressurized in steps until failure occurred. No visual indications of distress were evident prior to failure, although the strains on metal components exceeded 1.2% and strains recorded by the embedded concrete gages were approximately 1%. Failure occurred by abrupt punching shear at approximately 99.3 MPa (14,000 psig), thereby expelling the central section with considerable force. The failure surface was that of a truncated cone. (ERA citation 04:013261)