While the White House may no longer regard dismantling the Energy Department as one of its top priorities, the Reagan administration has not given up trying to cut back some of its activities.

In fact, the administration has proposed such deep personnel cuts for fiscal 1984 in several divisions that it would violate congressionally mandated minimum staffing levels.

According to documents submitted to the Senate Energy and Natural Resources Committee, the administration wants to cut Conservation and Renewable Energy, which has a congressionally mandated floor of 352 employes, to 210; Fossil Energy, with a floor of 754, to 591; the Economic Regulatory Administration, with a floor of 450, to 146; and the Energy Information Administration, with a floor of 490, to 480.

To achieve this, the administration in an appendix to its fiscal 1984 budget request is seeking the repeal of the minimum staffing requirements. Congress is viewing the idea with skepticism, to say the least. TV TIME . . . Even opponents of the administration's bill to decontrol natural gas give Secretary Donald P. Hodel high marks for mastering the intricacies of this complex issue.

Hodel, who confesses that he probably has spent more than half his time on the issue since he took office in November, now feels comfortable with the subject and has launched a blitz of appearances on network TV shows in an effort to sell the administration's arguments.A VACANCY UPDATE . . . Congressional committees that oversee the department are becoming increasingly restless over the administration's failure to fill five key vacancies in the department, including the No. 2 and No. 3 positions. No successor has been named to replace former deputy secretary W. Kenneth Davis, who was eased out in December, and the undersecretary's position has been allowed to remain empty for an entire year.

The department also has three other key vacancies: assistant secretary for international affairs, director of the Office of Alcohol Fuels and director of the Office of Civilian Nuclear Waste Management. MEANWHILE, LOWER ON THE LADDER . . . While no names have been circulated recently as candidates for the top posts, there have been several names mentioned for the lower-ranking position of head of the new nuclear waste management program. They include Frederick M. Bernthal, the chief legislative assistant to Sen. Howard H. Baker Jr. (R-Tenn.), and J. Bennett Easterling, a former Nuclear Regulatory Commission staff member who works in the office of Rep. Trent Lott (R-Miss.).