(The Hill) — The Biden administration is vacating a decades-old decision to revoke the security clearance of World War II-era scientist J. Robert Oppenheimer, who is known today as the “father of the atomic bomb.”

In a written statement first shared with The Hill, Energy Secretary Jennifer Granholm said the 1954 decision barring Oppenheimer’s clearance went through a “flawed process” and said there was evidence of bias. 

“In 1954, the Atomic Energy Commission revoked Dr. Oppenheimer’s security clearance through a flawed process that violated the Commission’s own regulations. As time has passed, more evidence has come to light of the bias and unfairness of the process that Dr. Oppenheimer was subjected to while the evidence of his loyalty and love of country have only been further affirmed,” Granholm said. 

“I am pleased to announce the Department of Energy has vacated the Atomic Energy Commission’s 1954 decision In the Matter of J. Robert Oppenheimer,” she added.

Oppenheimer directed the Manhattan Project’s Los Alamos Laboratory when the atomic bomb was being developed during World War II.

His security clearance was later revoked by the Atomic Energy Commission, a federal agency that predated the Energy Department, with commissioners arguing he was a “security risk” amid allegations that he was disloyal.

Oppenheimer’s past connections with communism and communists also played a role. His hearing before the commission in 1954 occurred during the Red Scare, a time where U.S. politics was dominated by anti-communist sentiment.

Documents from his hearing that were declassified in 2014 raised doubts about the disloyalty accusations, suggesting, for example, that his opposition to the hydrogen bomb project was for technical and military reasons rather than pro-Soviet sentiments. 

The move from the Energy Department comes ahead of the release of an eponymous movie about Oppenheimer from director Christopher Nolan. The film is slated for release this summer.

It also comes amid a new development in nuclear energy. Earlier in the week, the department announced a breakthrough for nuclear fusion energy, getting a net-energy gain out of this type of reaction for the first time. 

The department has previously acknowledged Oppenheimer’s scientific work, including the 2017 creation of the Oppenheimer Science and Energy Leadership Program that supports early and mid-career scientists. 

The Atomic Energy Commission also granted Oppenheimer its Enrico Fermi Award in 1963 for his scientific work.