The state of Massachusetts argued at the U.S. Court of Appeals for the First Circuit that the U.S. Nuclear Regulatory Commission didn’t fully incorporate lessons from the Fukushima, Japan radiological accident when relicensing a local nuclear power plant.

The December 5 oral argument concerned the state’s appeal of the commission’s grant of a 20-year license extension to the Pilgrim nuclear power plant in Plymouth, Mass. The state is also challenging the NRC’s denial of its petition for review.