According to WRC-368 if the pad width is greater that 1.65 SQRT (RT) then it is assumed that the stresses at the pads edge will be reduced to an acceptable value at that location (i.e, all local nozzle stress effects will be essentially gone). Also some FEA calculation reports have also indicated that at about 9T distance from the edge of the nozzle the local discontinuity nozzles stresses due to piping loads have all diminished so that only general membrane stresses exists.

Question: if this is the case then why should a WRC-107/297 stress check be performed at the R-pad edge at all if the width of the pad is 1.65 SQRT (RT)or greater? I have come across a case where an FEA report calc predicts a stress of about 20,000 psi, which is all just general membrane, at the pads edge but WRC-107/297 predict close to 140,000 psi total membrane + bending for the same configuration and loading (although at the nozzle to shell/pad connection the stresses calculated are in close agreement). Seems like this is erroneous results from the WRC-107/297 calc since even WRC-368 ignores stresses at the pads edge if the pad width is greater than 1.65 SQRT(RT). In my understanding of this, if the pad is of a width 1.65 SQRT(RT) then no stress check is required at the pad edge or at least should not be done with WRC-107 or 297, in paticular since there will be super high erroneous stresses calculated by these programs there.

Could you explain why Caesar II WRC calcs consider stresses at pads edge in light of the above potential for super high erroneous results? And do you agree that if the pad is at least 1.65 SQRT(RT) wide then no stress check is required at the pad edge?