Amazon’s (NASDAQ:AMZN) plan to build a data center powered by a Pennsylvania nuclear power plant has not changed, even as the top U.S. energy regulator has turned down a request to increase power to the facility.

Chairman Willie Phillips dissented from the decision on the “first of its kind” co-location proposal, saying it could harm national security and grid reliability.

The Federal Energy Regulatory Commission (FERC) rejected an effort Friday to allow an Amazon data center to tap into additional power from a nearby Pennsylvania nuclear plant. The decision could throw a wrench in efforts by large technology companies to secure so-called “behind the meter” power from nuclear plants as they seek to meet