(Adds details throughout on amount of power supplied, duration of contracts and comments from Constellation and U.S. government)

By Laila Kearney and Timothy Gardner

NEW YORK/WASHINGTON, Jan 2 (Reuters) - Constellation Energy has been awarded a record $1 billion in contracts to supply nuclear power to the U.S. government, the company said on Thursday.

Constellation, the country's largest operator of nuclear power plants, will deliver electricity to more than 13 federal agencies, as part of the agreement with the U.S. General Services Administration.

The GSA estimated that the contracts, set to begin on April 25, will comprise over 10 million megawatt-hours over 10 years and provide electricity equivalent to powering more than 1 million homes annually.

The procurement will deliver electricity to 80 federal facilities located throughout the PJM Interconnection, a regional transmission operator that covers parts of 11 mid-Atlantic and Midwest states and the District of Columbia. The U.S. Department of Transportation, the Federal Reserve Board of Governors and the Army Corps of Engineers are some of the facilities that will get the power.

Constellation said the deal will enable it to extend the licenses of existing nuclear plants and invest in new equipment and technology that will increase output by about 135 megawatts.

“The investments we make as a result of this contract will keep these plants operating reliably for decades to come and put new, clean nuclear energy on the grid while making the best use of taxpayer dollars," Joe Dominguez, president and CEO of Constellation said in a release.

The GSA said in the face of uncertainty over future electricity prices and soaring power demand from data centers and AI facilities, the contracts will provide federal agencies with budgetary stability by keeping electricity costs fixed for 10 years.

Robin Carnahan, the GSA administrator, said the deal demonstrates "how the federal government can join major corporate clean energy buyers in spurring new nuclear energy capacity and ensuring a reliable, affordable supply of clean energy for everyone."

(Reporting by Laila Kearney and Timothy Gardner; Editing by Bill Berkrot)

((Laila.kearney@thomsonreuters.com; (917) 809-0054;))