This paper demonstrates the implementation of Six Sigma in a nuclear piping facility of a Nuclear Research organization in India to reduce the GTAW defect of “Tungsten Inclusion” in SS pipe weld joints and thereby enhance nuclear safety and also reduce project overrun and rework cost. This study verifies the applicability of DMAIC methodology in implementing Six Sigma in GTAW process, a non-repetitive activity. The findings of the research suggests devotion of serious consideration to welders‟ skill, experience in GTAW and formal technical qualification in order to reduce „Tungsten Inclusion‟ defect in GTAW process. Till date no comprehensive research has been undertaken to implement Six Sigma in GTAW process. The challenging issue of choosing the correct approach and tools and the nonexistence of research in this field motivated the study.  

Keywords: Six Sigma, DMAIC, DPMO, GTAW, Weld Defects, Tungsten Inclusion. IGCAR, Nuclear piping facility