Washington — The power structure of the new, Republican-controlled Senate that will be installed in January has a conservative look that should help it work well with the incoming Reagan administration.
Some of the switches in committee chairmanships from Democrats to Republican suggest sharp reversals in policies, while others herald little change. But the net impact seems to be a discernible shift to the right.
Here is a rundown on the probable new chairmen of principal Senate committees , based on the seniority rankings that normally determine chairmanships:
Agriculture. Jesse a. Helms (R) of North Carolina, who will most likely succeed the defeated Herman E. Talmadge (D) of Georgia, is expected to downgrade Democrats' traditional interest in food stamp and nutrition programs.
Appropriations. Mark O. Hatfield (R) of Oregon, expected replacement for the defeated Warren G. Magnuson (D) of Washington, is a middle-roader on government spending who probably will wield a more stingy gavel than did his fellow senator from the Pacific northwest. The new chairman has, however, opposed the Reagan-backed Kemp-Roth proposal.
Armed Services. John G. Tower (R) of Texas probably is as firm a proponent of strong defense measures and heavy military spending as the present committee chairman, John C. Stennis (D) of Mississippi.
Banking, Housing, and Urban Affairs. Edwin J. (Jake) Garn (R) of utah, unlike present chairman William Proxmire (D) of Wisconsin, is a staunch critic of domestic programs who may try to pare US housing programs.
Budget. Pete V. Domenici (R) of New Mexico probably can be counted as a stout ally of President-elect Reagan in reducing the money spent on federal social programs. He supports the Kemp-Roth plan.
Commerce. robert W. Packwood (R) of Oregon may inject more environment awareness into this committee, which oversees commerce and transportation from the oceans of the airways, than has departing chairman Howard W. Cannon (D) of Nevada.
Energy. James A. McClure (R) of Idaho favors dismantling federal controls on energy and granting maximum freedom to the private energy industry -- a sharp departure from the approach of the present chairman, Henry M. Jackson (D) of Washington.
Environment. Robert T. Stafford (R) of Vermont, in line to succeed Jennings Randolph (D) of West Virginia (unless he opts instead to chair the labor committee), is a moderate with environmentalist inclinations.
Finance. Robert J. Dole (R) of Kansas would likely bring a more party-line, conservative thrust to tax and revenue legislation than has longtime chairman Russell B. Long (D) of Louisiana.
Foreign Relations. Charles H. Percy (R) of illinois appears to have an internationalist outlook broadly similar to that of the defeated Frank Church (D) of Idaho.
Intelligence. Barry M. Goldwater (R) of Arizona is likely to prove a less critical watchdog of the intelligence community than the defeated Birch Bayh Jr. (D) of Indiana.
Judiciary.Strom Thurmond (R) of South Carolina, one of the most conservative men in the Senate, is expected to curb the liberal activism which the committee assumed under Edward M. Kennedy (D) of Massachusetts.
Labor. Orrin G. Hatch (R) of Utah, who is like to chair this committee if Senator Stafford does not, is a leading opposnent of the labor law reform sought by the AFL-CIO. Outgoing chairman Harrison A. Williams Jr. (D) of New Jersey has been an outspoken proponent.