HTMP Quarterly Progress Report (January 1978)

Introduction of the improved techniques for monitoring and controlling the creep programme has resulted in the utilisation increasing to the 80% level. In terms of the technical output attention has been concentrated on organising the data generated on the prime candidate materials for application in Advanced HTR systems and data generated on individual alloys together with the evaluation and the corresponding metallurgical examination will be presented in a series of Review Reports. Evaluation is now being carried out on an individual basis for each of the first priority PNP alloys Hastelloy alloy X, Hastelloy alloy S, Inconel alloy 617, IN 586, Incoloy alloy 800H, Incoloy alloy 802, IN 519 and Manaurite 36X. In collaboration with IRW, log stress/log time creep data plots have been compiled for all available data from 0.2% creep strain to rupture. Wherever possible comparisons are made with manufacturers data. A series of reports covering the properties of each alloy, and the corrosion and carburisation behaviour in the HTR environment for exposure times up to 10000 - 15000 hours are currently in preparation.