Residual stresses are detrimental to performance of large reactor components, and knowledge of the stress state in the manufactured components is necessary in order to carry out structural integrity assessments. Post-weld heat treatment restores toughness in the vicinity of welds and, to a lesser extent, relieves residual stresses. However, some level of residual stress remains. In order to reduce the residual stresses, we can choose a welding process in which the extent of the regions subject to high-level tensile stresses is minimised. It is postulated that laser-based processes will achieve significant reductions in the residual stresses in comparison to conventional arc welding and electron beam welding processes. The focus of this proposal is to explore the residual stress developments in these laser welds.