High-definition radiography of tube-to-tubesheet welds of steam generator of prototype fast breeder reactor

In the steam generator of the Prototype Fast Breeder Reactor (PFBR), steam is generated by the transfer of heat from secondary sodium to water. Due to the inherent dangers of sodium-water reaction, the integrity of weld joints separating sodium and water/steam is of paramount importance. This is particularly true and very important for the tube-to-tubesheet joints. This paper discusses the use of projective magnification technique by microfocal radiography for the quality evaluation and optimisation of the welding parameters of such small tube-to-tubesheet welds of the steam generator of PFBR. It should be mentioned here that in a recent article on microfocus radiography (1) , Dr Halmshaw observed that little had been published on the application of projective magnification techniques using microfocal radiography for similar small-bore pipe welds.