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.

Talen Energy (TLN) and Amazon (AMZN) shares fell over 2% and 1%, respectively, on Monday. The decline came after the U.S. Federal Energy Regulatory Commission (FERC) denied a request to increase the power supply from TLN’s Susquehanna nuclear plant to AMZN’s data center campus.

The US Federal Energy Regulatory Commission (FERC) has rejected a proposal that would have allowed an Amazon data centre

The commission agreed with opponents of the proposal, citing concerns about grid reliability and cost fairness.

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.

Constellation Energy will continue to pursue deals to develop data centers on the sites of its U.S. power plants, days after federal regulators dealt a blow to the so-called co-located arrangements, company executives said on Monday.

The Federal Energy Regulatory Commission (FERC) has rejected an amended interconnection agreement that would have supported expanded co-located load at an

Nuclear-power stocks slumped on Monday after US regulators barred a plant from supplying extra power to an Amazon data center. The Federal Energy Regulatory Commission rejected the deal between Amazon and Talen Energy late last week.

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

Talen said it believed FERC had erred and was evaluating its options. The company can still restructure its expanded deal with Amazon, according to Oppenheimer analysts.