The California Public Utilities Commission in San Francisco issued a staff citation Tuesday with an $8.1 million fine to PG&E for allowing a contractor to conduct inadequate X-ray tests on natural-gas pipeline welds.

The commission staff said in the citation that a PG&E employee discovered March 26 that an outside contractor was performing radiographic tests on a pipeline in Brentwood that didn’t meet a federal requirement for evaluation of the full circumference of a line.

The citation said PG&E fired the contractor and conducted new tests on that line, and also conducted an internal review that found 224 previous instances where the same contractor violated the requirement.

The planned $8.1 million fine is for the 224 previous violations. PG&E has 10 days to either pay the penalty or begin an appeal process before a CPUC administrative law judge.

Asked whether the utility plans to appeal, PG&E spokeswoman Brittany Chord said, “We are reviewing the decision and will respond accordingly.”