Supergrade bureaucrats who left the security blanket of the civil service system expecting to get a shot at bigger financial rewards in return for added risks are learning a little about the latter these days.

The Carter administration set up the Senior Executive Service to provide a cadre of top career officials who would be more responsive to their political bosses. SES enlistees traded in much of their tenure and appeal rights in transfer and dismissal actions for the promise of higher pay and bonuses. Although there is no doubt that the Carter people acted only in the interests of good government, one suspects that they had hoped to be around for a second term to put the SES through its paces. That, as well all learned on Nov. 4, was not to be.

Rules of the SES provide that an incoming administration cannot involuntarily replace SES personnel until 120 days after the inauguration. The idea was to create a three-month getting-to-know-you period during which new political appointees could meet, work with and evaluate the career staff they inherited. Calendar-watchers are aware that that 120-day period is up. Some SES reassignments have already been made (at Justice and Energy) and others are in the works in departments and agencies. SES people are tense.

Some political appointees are delighted with the career executives they have. Others are less so. Some have checked performance, or the party affiliation, of their $50,000-a-year career staffers and have decided they would be better off in other assignments.

Insiders expect there will be large-scale reassignments of SES personnel in weeks and months ahead, after agency RIF (reduction in force) plans are completed, and when new rules covering the job security, or lack of same, for SES members are issued. Those proposed new rules, which deny SES members fall-back rights to Grade 15 career jobs or to placement in other SES vacancies, are now at the Office of Management and Budget (White House) for review. They should be back at the Office of Personnel Management within a few days, and published sometime later this month.