Abstract
British Energy funded a large programme to pre-emptively investigate the use of structural weld overlays
(SWOLs) to mitigate against crack initiation and growth within the dissimilar metal welds (DMW) found in the
pressuriser safety/relief valve nozzle components in their Sizewell B nuclear power plant (NPP). Deep-hole drilling
(DHD) measurements were carried out to provide confidence in and hence validate the residual stresses predicted
along the DMW centreline of the “virgin” and “overlaid” nozzle using finite element analysis (FEA). The predicted
residual stresses were then used for subsequent fatigue crack growth rate analysis. The residual stresses measured at
all three locations within the “virgin” nozzle were in very good agreement, while for the “overlaid” nozzle good
agreement was seen at depths greater than 25% from the inner surface of the nozzle. It was found that the SWOL
reduces the magnitude of the tensile stresses in the underlying DMW and causes a much deeper compressive stress
zone. Relatively good agreement was observed between the FEA results and the measurement results.
| Translated title of the contribution | Through Thickness Residual Stress Measurement in a Full Structural Weld Overlay on PWR Pressuriser Nozzle |
|---|---|
| Original language | English |
| Title of host publication | International conference on Structural Mechanics in Reactor Technology |
| Pages | 1 - 8 |
| Volume | Div-II: Paper ID 153 |
| Publication status | Published - 2011 |