Millions of older Americans who fear that the senior citizen soon to be in the White House will wipe out old-age benefit can rest easy. It's true that Ronald Reagan years ago voiced serious doubts about the system and suggested it be made voluntary. But political realities, if nothing else, have changed Reagan's mind. Far from scuttling the program, Reagan will move cautiously to put Social Security on a sounder basis.

William driver, commissioner of the Social Security Administration for a year, is not a Reagan man, but has been working closely with the transition team -- and, perhaps significantly, has not been asked to submit his resignation. He is convinced the Republican's approach will be more moderate than the long-ago Reagan campaign rhetoric with which Jimmy Carter tried to scare older voters.

Driver told my associate Indy Badhwar: "I think scare stories in the press have done more to frighten Americans about the end of Social Security than anything the Reagan people have indicated."

The biggest obstacle obstacle to financial health for the Social Security system is Congress. The lawmakers have never been overly reluctant to increase the coverage of the program and the size of its benefits. But they have proven consistently timorous about making the unpopular revenue-raising decisions that must pay for this openhandedness.

This is the year when Congress will have to bit the bullet. Social Security disbursements amount to a staggering total of $10 billion a month. It's obvisouly out of the question to cut off this significant portion of consumer income. And politically, the public wouldn't stand for it.

But inflation and unemployment have pushed Social Security to the brink of disaster. Benefits are tied to the Consumer Price Index, so they increase with every hike in the cost of living. Meanwhile, continued high unemployment means workers and employers are contributing less in payroll taxes, which are the trust fund's only source of revenue.

Reforms enacted in 1977 were touted as the "final solution" to Social Security's predicament. Both the rate of the payroll tax and the salary base on which it was collected have been raised significantly -- as millions of workers discovered to their dismay on their first 1981 paychecks.

That should have been enough to balance the income-outgo equation. But the 1977 experts made one miscalculation that has invalidated their rescue effort. They figured that inflation, while increasing the amount Social Security would have to pay out, would also increase taxable wages enough to cover the difference. But for the first time, wages failed to keep pace with the consumer prices on which benefit payments are calculated. t

Driver is not pessimistic about the chances of restoring the program to fiscal health. While there are no "quick fixes" Congress can make, he listed these possible solutions:

Transfer the nearly one-fourth of current payroll taxes that go into the Medicare hospital fund to the retirement and survivors fund, and finance Social Security's hospital costs out of general revenues. That alone would be enough to solve thesystem's problem.

But "Americans are rugged individualists who believe that they've paid their own way for Social Security hospital costs," Driver said. "Any suggestion of financing this [hospital] program through general revenues taints the program as welfare-oriented."

Borrown on a regular basis from general revenues to keep the trust fund afloat, paying interest rates set by the Treasury.

Raise the payroll taxes still more, and raise the retirement age from 65 to 68 -- a possibility the Reagan special task force has been exploring.

Change the way Social Security benefits are pegged to the cost of living.

Any or all of these changes would see the system safely through the year 2010, Driver predicts. But by 2030, when the post-Korean War babies are ready for retirement, he said, "it's hard to say what will happen."