rmsaj;
Regarding failure rates and infant mortality statistics for UPV built to ASME Section VIII Div 1, I would think that the National Board would have all those statistics since the member jurisdictions are required to report boiler and upv incidents on a regular basis. Another source may be...
Deanc is right in referencing the NBIC.
In addition, you might want to consider doing the internal inspection while the vessel is still under warrentee to determine if there may be installation or initial construction defects. If there is then get it on the installers budget not yours.
FYI,
You might want to check ASME Section VIII Div 1 as there are certain circumstances where an electric steam generator may be constructed under those rules.