A letter sent by the leaders Wednesday pointed to a leaked email last month from the head of an NRC inspection team that raised questions about New Orleans-based Entergy Corp.'s ability to operate the plant safely.
Wednesday's letter was signed by Republican Gov. Charlie Baker and Attorney General Maura Healey, U.S. Sens. Edward Markey and Elizabeth Warren and the state's entire congressional delegation — all Democrats.
The NRC is currently inspecting Pilgrim citing recurring safety issues at the plant, scheduled to close in 2019.
Entergy was forced to shut down the plant last month after leaks were found in several steam valves.