Rick Perry, Vogtle, Resignation Letter

U.S. Secretary of Energy Rick Perry pictured here at Plant Vogtle in Georgia. Plant Vogtle is about one hour away from Aiken.

In a resignation letter tendered to President Donald Trump, U.S. Secretary of Energy Rick Perry reviewed his department's accomplishments over the years, including nuclear cleanup and weapons work, both of which are conducted at the Savannah River Site.

"The Department of Energy has also embraced, with success, the national security mission of modernizing our nuclear enterprise to make sure our weapons are safe and work as designed," Perry wrote, after mentioning work across the various national labs, one of which is directly south of Aiken. "We have also achieved unprecedented success in the clean-up of our nuclear facilities."

In a July interview with Fox News, Perry described the country's nuclear arsenal as the "most developed" and up-to-date "in the world." The energy secretary said modernization efforts are well underway, ensuring weapons will "work as advertised" – if ever needed.

"In some cases there's weapons that are 40 years old," he said in the interview, which took place in Jerusalem. "As any type of product, it's going to have some degradation. We have the process in place to make sure that our weapons are as modern … and in the right condition as they need to be."

Rick Perry SRS (copy)

U.S. Secretary of Energy Rick Perry during his 2018 tour of the Savannah River Site.

Perry's resignation letter was posted to the Energy Department's website Thursday, the same day news broke of his resignation, which is effective later this year.

Footage from Perry's tour of Plant Vogtle, across the river in Georgia, is prominently featured in a farewell video posted to his official Twitter account.

On Thursday night, National Nuclear Security Administration chief Lisa Gordon-Hagerty thanked Perry "for all" he has done to advance the nation's energy and nuclear security fields.

The NNSA is the Energy Department's semiautonomous agency in charge of nuclear weapons and related nonproliferation.

Under Perry's watch – not over yet – the federal government managed to terminate the never-finished, multibillion-dollar Mixed Oxide Fuel Fabrication Facility at SRS, something both the Obama and Trump administrations had been angling to do.

In May 2018, the NNSA and the U.S. Department of Defense jointly recommended repurposing MOX's bones for an enduring nuclear weapons mission: plutonium pit production. Related efforts are already underway.

Gordon-Hagerty in a mid-June interview with the Aiken Standard said both Perry and Trump support a healthy nuclear complex.

"They are absolutely wedded to the prospect of making sure that we have a robust and a resilient enterprise," the NNSA administrator said. "Not only now, but in the future."

"Now more than ever, I believe strongly in the mission of the Department of Energy," Perry wrote in his signing off. "The people across the enterprise have a sincere commitment to this country."

Colin Demarest covers the Savannah River Site, the U.S. Department of Energy, the National Nuclear Security Administration and government in general. Follow him on Twitter: @demarest_colin