The effect of residual stresses generated by load history on fracture has been investigated through experimental and numerical studies. In this paper the application of a “local approach” to determine the change in applied load to cause fracture is described. Then the R6 defect assessment procedure is presented. The effect of tensile residual stress on brittle fracture of ferritic steel type A533B at -150ºC is explored. The modified J-integral, J
has been also used to estimate the combined crack driving force during loading to fracture of the specimens containing tensile residual stresses ahead of a crack/notch. It is shown that by having more accurate estimates of driving force created by the residual stresses leads to increased agreement between experiments and assessment.