Lloyd served on the House Science Committee for her entire congressional career. That committee had jurisdiction over legislation related to nuclear power facilities at Oak Ridge in her district. By the time of her retirement from Congress, she was the second-ranking Democrat on the committee. She was a strong advocate for the Clinch River Breeder Reactor project in Oak Ridge. She also served on the Committee on Public Works (1975–87), on the Armed Services Committee (1983–95), and on the House Select Committee on Aging for much of her congressional career.