The name of Mark Andrews, Republican of North Dakota, was inadvertently omitted from a list of newly elected senators published in yesterday's Washington Post. Andrews, 53, a member of the House since 1963, was elected to succeed Sen. Milton Young (R-N.D.), who is retiring.

Jubilant Republicans yesterday laid claim to the Senate for the first time in a quarter century after winning a dozen seats in a sweeping purge of Democratic liberals in Tuesday's elections.

The GOP's possession of 53 of the 100 Senate seats, stunning as it is, pales by comparison with the dramatic ideological shift in the composition of the Senate and the radical changes that will occur in many important Senate committee chairmanships when the 97th Congress convenes in January.

Among the most significant power shifts on committees, Sen. Strom Thurmond (R-S.C.), a longtime foe of civil rights legislation, will succeed Sen. Edward M. Kennedy (D-Mass.) as chairman of the Senate Judiciary Committee. Sen. Orrin Hatch (R-Utah), organized labor's nemesis in the Senate, is in line to take over from Sen. Harrison A. Williams (D-N.J.), a prolabor man, as head of the Senate Labor and Human Resources Committee.

Also Sen. Jesse Helms (R-N.C.), a leader of the ascendant New Right bloc in the Senate, can claim the chairmanship of the Agriculture Committee from veteran Sen. Herman E. Talmadge (D-Ga.), who lost not only his committee post but also his seat in a surprise defeat at the polls Tuesday night.

Sen. John Tower (R-Tex.) is in line to take over from Sen. John C. Stennis (D-Miss.) as chairman of the Armed Services Committee, probably strengthening the hand of the Pentagon in lobbying on Capitol Hill. p

In what could be a major setback for environmentalists, conservative Sen. James A. McClure (R-Idaho) is in line to take over the Energy and Natural Resources Committee from Sen. Henry M. Jackson (D-Wash.), assuming that the current ranking minority member, Sen. Mark O. Hatfield (D-Ore.), picks up the Appropriations Committee chairmanship now held by defeated Sen. Warren G. Magnuson (D-Wash.). McClure is an ardent proponent of energy development, including nuclear power.

And on the Banking Committee, Sen. Jake Garn (R-Utah), a stauch Rocky Mountain conservative, is poised to take over from Sen. William Prosmire (D-Wis.).

Switches at the top on other committees also reflect a more conservative drift, although probably not as dramatically. The main losers in Senate influence -- and possibly in the elections as a whole -- are civil rights activits, environmentalists and especially labor unions.

"The swing in the Senate is probably even greater, in ideological terms, than the shift in the White House," a prominent labor leader said yesterday. "A bleeping disaster," said another.

A key question is the extent to which the resurgent right tries to use its new muscle to claim the perquisites of its power, which could determine whether Sen. Howard H. Baker Jr. (R-Tenn.), the current minority leader, takes over from Sen. Robert C. Byrd (D-W.Va.) as majority leader in January.

Asked about a call from some New Right leaders for his replacement as GOP leader in the Senate, Baker told reporters yesterday that he believes he has at least 40 votes to become majority leader, many more than enough to be elected by the Republican bloc in the Senate.

Baker, a party moderate who tried unsuccessfully for the Republican presidential nomination earlier this year, also said that Sen. Paul Laxalt (R-Nev.), the campaign chairman for President-elect Ronald Reagan, has agreed to place his name in nomination for the majority leader's job.

"If they [the New Right leaders] think Howard Baker is going to roll over and play dead for them," said Baker, "they are mistaken."

But speculation continued yesterday, nonetheless, about possible moves by the most conservative of the Senate Republicans -- their numbers vastly expanded by results of Tuesday's election upsets -- to extend their spheres of influence.

For instance, although Sen. Charles Percy (R-Ill.), a moderate, is in line to take over as chairman of the Senate Foreign Relations Committee, some committee sources said they expected a bid by conservatives to win the post for Helms, who ranks just behind Percy and Baker on the Republican seniority list for the committee.

The current chairman of the Foreign Relations Committee, Sen. Frank Church (D-Idaho), lost not only his chairmanship but also his seat -- a fate shared by Talmadge on Agriculture and Magnuson on Appropriations.

Other committee chairmen who went down to defeat were Birch Bayh (D-Ind.), who led both the Senate Intelligence Committee and the special subcommittee that investigated Billy Carter's ties to Libya earlier this year, and Gaylord Nelson (D-Wis.), who headed the Small Business Committee.

Church was defeated by Rep. Steve Symmn (R), Talmadge by former Georgia state Republican chairman Mack Mattingly, Magnuson by Washington state Attorney General Slade Gorton, Bayh by Rep. Dan Quayle (R) and Nelson by former Rep. Robert W. Kasten (R). All but Gorton are considered strong conservatives.

Talmadge was a consertative among the Democrats, but most of the others on the long Democratic casualty list were liberals, including some of the left's most prominent leaders.

Late yesterday, Republican Sen. Barry Goldwater (D-Ariz.) kept his seat when Democrat Bill Schultz conceded. The race had been the toughest the 1964 presidential nominee and the GOP's "Mr. Conservative" had faced during his career. Goldwater, like Magnuson, suffered at the polls from old age and the appearance of physical infirmity; both men are in their 70's.

Perhaps the most dramatic of the liberal Democratic losses was the defeat of Sen. George McGovern (D-S.D.), the Democrats' 1972 presidential nominee, at the hands of Rep. James Abdnor (R).

Another liberal who went down was Sen. John C. Culber (D-Iowa), who will be succeeded by Rep. Charles Grassley (R), who, like Abdnor, is a staunch conservative.

Sen. John Durkin (D-N.H.), another liberal, was turned out by former New Hampshire attorney general Warren Rudman (R), who is regarded as more moderate than most of his incoming Republican collegues.

In North Carolina, Sen. Robert Morgan, a moderate Democrat, was supplanted by college professor John P. East (R), who is among the most conservative of the GOP newcomers.

Republicans took all three states where Democratic incumbents were unseated in party primaries earlier this year.

In Florida, Paula Hawkins (R) defeated Democrat Bill Gunter to succeed Sen. Richard Stone (D), whom Gunter beat in a primary. Hawkins, a consumer advocate and moderate conservative, will become the second woman in the Senate, joining Sen. Nancy Kassebaum (R-Kan.).

Frank H. Murkowski (R), a Fairbanks, Alaska, Banker, outdistanced Democrat Clark Gruening to take over the seat by Sen. Mike Gravel (D).

Retired admiral Jeremiah Denton (R), a favorite of the fundamentalist Moral Majority that was active in a number of Senate campaigns this year, defeated former Public Service Commissioner Jim Folsom, son of a former Alabama governor, in the race to take over from Sen. Donald Stewart (D-Ala.)

In New York, Republican Alfonse D'Amato claimed the seat of Sen. Jacob K. Javits (R), although the race was close enough to prompt Rep. Elizabeth Holtzman (D-N.Y.), his Democratic opponent, to say she wanted a recount. Javits, who had been defeated by D'Amato in the Republican primary, came in third running on the Liberal Party label.

In races to succeed three retiring Republican senators, Rep. Mark Andrews (R) won in North Dakota, former Philadelphia district attorney Arlen Specter (R) won in Pennsylvania and state Sen. Don Nickles (R), another favorite of the Moral Majority, won in Oklahoma.

In races to succeed two retiring Democratic senators, the Democrats won: Rep. Christopher Dodd in Connecticut and Secretary of State Alan J. Dixon in Illinois.

In two races that were too close to call on Tuesday night, Sens. Patrick J. Leahy (D-Vt.) and Gary Hart (D-Colo.) pulled out narrow victories in two of the rare liberal successes of the evening. Two moderately liberal victors were Sen. Thomas F. Eagleton (D-Mo.) and Sen. Dale Bumpers (D-Ark.). Big liberal winners were Senate Majority Whip Alan Cranston (D-Calif.) and Sen. Daniel Inouye (D-Hawaii). Senate Budget Committee Chairman Ernest F. Hollings (D-S.C.), a more moderate Democrat, also won a big victory.

Senate Finance Committee Chairman Russell B. Long (D-La.) won reelection last September by pulling out a majority in Louisiana's unusual winner-take-all primary election.

A total of 34 Senate seats were at stake in this year's elections, 24 held by Democrats and 10 by Republicans. The Republicans needed to add nine seats to the 41 that they currently hold to take control because Vice President-elect George Bush could break a 50-50 tie in organizing the Senate next January.

At one point it appeared that Sen. Harry F. Byrd Jr. (Ind.-Va.) might also be instrumental in deciding control of the Senate. But it now appears that his vote won't matter. Byrd, a former Democrat, has voted with the Democrats to control the Senate but has come under periodic pressure from the Republicans to switch sides. Byrd endorsed Reagan this year and there was some speculation that he might switch parties, but Byrd said in endorsing Reagan that he did not intend to do so.

In commenting on the results of Tuesday's elections, Majority Leader Byrd expressed intense regret at the Democratic losses that will soon make him minority leader, but said they may turn out to be a "healthy shock" for the party. "I think we need to regroup and unify and come up with a program of our own," said Byrd, who promised cooperation with the new Republican president and Republican Senate majority leader but also vowed to oppose them when there are "honest differences" on issues.

Byrd conceded that the Senate will be more conservative next year but added that "as the world of reality is faced up to . . . perhaps it won't be quite as conservative as it might seem."

Baker appeared to say somewhat the same thing in noting that moderates as well as conservatives played a part in the presidential and congressional victories on Tuesday. He said he thought Republican moderates and conservatives would have no difficulty working together. He also said he anticipated no trouble working with the somewhat shrunken Democratic majority in the House but acknowledged that House-Senate conferences may be "a little more tumultuous" than normal. He dismissed notions of a legislative paralysis in the Senate because of the close party-line split. But he summed up the Republican victories in historic proportions: "not only a landslide but a political earthquake."