Because of the high first-year costs involved in firing bureaucrats (government-paid severance and unemployment benefits), the Reagan administration is considering furloughs, mixed with layoffs, to reduce spending for the fiscal year that begins next month.

Most federal officials here claim they are in the dark as to the extent or timing of major personnel cuts that President Reagan's budget chief, David Stockman, has said will be announced beginning next week.

This column has learned that technicians at the Office of Personnel Management were recently directed -- by Stockman's office -- to come up with a report dealing with the legality and cost-savings of using furlough procedures, rather than reductions in force (RIFs), to cut the government payroll.

Although the number of RIFs in government so far has been relatively small (compared to the size of the work force), federal agencies have found RIFs disruptive (with senior workers bumping less senior types out of jobs) and expensive.

A worker fired in a RIF situation can, depending on length of service, get up to one year's pay, and draw unemployment benefits (largely paid by his or her agency through state programs) for months or until he gets a new job. The General Accounting Office, in a special report for Congress, recently cited the RIF route as being an expensive way to trim the work force.

A number of agencies, among them the Army Corps of Engineers and Defense Department, used furloughs during the 1950s and 1960s, but since have got away from them by hiring seasonal employes for specified times of work.

Under furlough regulations, agencies can take employes off the payroll for "emergency" reasons (if the building burned down or working conditions were impossible), or for lack of funds or lack of work. (There are a number of agencies and programs Congress and the Reagan administration would like to choke off).

When an agency furloughs an employe, it must do so with the intention of rehiring that worker, in his same job, within a year. Agencies can also initiate RIF procedures if furloughs go beyond 30 days, but until the employe is separated he cannot qualify for severance payments.

An official, who said quoting him by name might land me in the hospital, said "they are kicking the furlough idea around. But it is a quick-fix that wouldn't save money in the long run unless the furloughed employe got tired of waiting" and found another job. In that case, the government could duck most if not all of its severance obligation, create an empty spot without RIF ripples and avoid paying unemployment benefits.

Before you decide to leap off the Washington Monument, be advised that the furlough idea is a contingency, and that lots of contingency plans are being kicked around. But the way things are going these days for federal workers, you might want to check out the hours the Monument is open to the public and when it is least crowded just in case.