In the year since Mikhail Gorbachev took charge of the Kremlin with a three-pronged mandate to reinvigorate the Soviet Union's leadership, restore its international reputation and revive its economy, he has amassed a record of unusual successes on two counts.

The yearlong shake-up of senior officials, topped by the election of five new members to the 12-man ruling Politburo, has resulted in a historic rejuvenation of the Soviet Communist Party and government.

Through the U.S.-Soviet summit meeting in Geneva last November and other foreign policy bids, Gorbachev has achieved some positive results, including a normalization in relations with the United States, China, Japan and the Third World -- although relations with the United States in particular are entering a more critical phase as he starts his second year.

But the 55-year-old Soviet leader's mission to resuscitate the ailing Soviet economy is marked by an apparent lack of consensus on methods -- and by potential resistance -- as shown by the outcome of the 27th Soviet Communist Party congress, which ended Thursday.

Aside from a new air of openness in the news media, and a hardening of discipline, Gorbachev's first year has brought no substantive changes in the fields of Soviet human rights, culture or other major domestic policies, based on the West's standards.

The pointed exhortation for "a radical reform" that Gorbachev sounded in opening the congress received few echoes in the ensuing nine days of podium debate. By his closing speech, Gorbachev, too, had dropped the term.

Even Premier Nikolai Ryzhkov, in the second most important address at the congress, stressed more conservative remedies than Gorbachev for accelerating economic growth, western analysts noted.

And congress delegates endorsed potential opponents of Gorbachev's economic policy by electing to the new 307-member Central Committee senior economic officials of the Leonid Brezhnev era who had been retired from office after Gorbachev came to power.

Despite Gorbachev's apparent stronghold of allies in the ruling Politburo, which makes major day-to-day policy decisions, his ultimate jury is the Central Committee.

That powerful body, elected every five years, accepts -- or rejects -- a Soviet leader's long-term policy direction. If a majority of its members object to Gorbachev's course, they can unseat him. In October 1964, the Central Committee passed a unanimous resolution to relieve Nikita Khrushchev of his duties.

The new Central Committee list released at the close of the party congress this week included a majority of members originally elected under Brezhnev.

In approving Gorbachev's opening report, however, the delegates gave him the go-ahead to carry out his policies during the next five years.

The program outlined by Gorbachev in the 15-year plan for economic growth, approved by the congress, and his 5 1/2-hour speech on Feb. 25 combine conventional methods of reindustrialization, scaling down the bureaucracy and raising productivity with a few novel concepts.

The concepts include reviving agricultural growth by allowing state farms to sell surplus production and probing a system of self-financing; reviewing the demand and pricing concepts; and possible reform of the Soviet system of credit and financing.

In his congress speech a week later, Ryzhkov, 55, avoided elaborating on such concepts. Instead, he emphasized the need for resource conservation, belt-tightening and increased capital investments.

But Ryzhkov's speech and others convinced western analysts here that broad consensus exists within the Soviet leadership for the general goals of economic recovery, including doubling production by the year 2000 and raising growth rates from 3.1 to 5 percent.

With the election of former Leningrad party boss Lev Zaikov to the ruling Politburo and the promotions of senior-level officials at the end of the congress, Gorbachev completed a year of personnel changes unparalleled since the era of de-Stalinization 30 years ago.

With five new Politburo members, 30 of 80 new ministers, a raft of new regional party secretaries, the appointment of Eduard Shevardnadze as foreign minister and Ryzhkov to the top government job, he has achieved a considerable reduction in age and an invigoration of approach within the leadership across the country.

He also achieved the election of 124 new Central Committee members -- a 40.4 percent change in that 307-member body.

In addition, Gorbachev maneuvered the retirement of full Politburo members Tikhonov, Viktor Grishin and Grigori Romanov, and candidate members Boris Ponomarev and Vasily Kuznetzov.

However, 183 -- or 59.6 percent -- of the Central Committee members elected under Brezhnev, including Ponomarev, 81, and Kuznetzov, 85, were returned.

Two old guard Politburo members -- Dinmukhamed Kunaev and Vladimir Shcherbitsky -- also remain, despite strong criticism of the former in the official Soviet press.

Western analysts in the Soviet capital consider the remaining Brezhnev-era Politburo and Central Committee members a potential brake on the pace of change, particularly in controversial social or cultural policy areas.

Despite heavy domestic duties, Gorbachev moved quickly to compile early foreign policy achievements -- in his October meeting with French President Francois Mitterrand and his November talks with Reagan and in dealings with a range of other countries.

Since the Geneva summit, the Kremlin has stepped up demands for concessions from Washington in response to its recent proposal to rid the world of nuclear arms by the year 2000.

By devoting the foreign policy section of his congress speech to a discussion of superpower relations and arms control, the Soviet leader established them as his foremost priorities between now and the next party congress, in 1991.

In two of his final actions at the congress, Gorbachev gave his diagnosis of the cause of tension in the U.S.-Soviet relationship, and his long-term cure for them. In harsh words, he accused "militarist, aggressive forces" in Washington of seeking "to freeze and perpetuate confrontation."

Minutes later, he announced that Anatoliy Dobrynin, 66, the Soviet Union's senior diplomat, one of its leading Americanists and for 24 years ambassador in Washington, would be returning to Moscow to a senior policy-making post as a secretary of the Central Committee.

If Dobrynin assumes the job of improving U.S.-Soviet relations -- and succeeds -- then Gorbachev will have heightened the role of a Secretariat member in resolving major policy conflicts.