Hello,

Not a metallurgist, but I think this is a classic shrinkage related porosity. Have seen several of it.
Since it is already pass the test, in theory there shouldn't be any issue. meaning that the raised face roughness and effective sealing area are still within tolerance.
However if your inspector suspect that there might be other issue and let say there is a doubt that porosity also occurs on other part of the body, then you might want to issue an NCR. It is a bit tricky though.
Not sure how you addressed the PO and its governing standard, but usually Inspection can go as far as ASME B16.34 Appendix I - Casting Radiographic Examination.

Personally, I have less concern on the raised face, but more on the 'thin' body part such as body neck, etc.

Hope that helps.
Regards,
D

Its a pretty confined picture, if you have a better picture with more of a location on the casting to id the actually riser locations and if the casting has any amount of production the ENG.DEPT at the foundry would or should have records when the pattern was poured and SAMPLED if that is a problem area?