Most of the eligible government executives say, in a confidential, unrealeased survey, they will enlist in the new high-reward, high-risk Senior Executive Service when it begins taking recruits in July.

But a majority of the top-paid civil servants in the "supergrade" (Grades 16 through 18) jobs also express fears that flexibilities in the SES will make it much easier for political appointees to abuse the system, play politics with federal programs and zap once-tenured executives who stand in their way.

That data, from the Federal Executives League, will be released officially tomorrow at a special Saturday session for government supergraders. The majority of the top-paid career employes live and work in Washington. Most of them will be offered a chance to join the SES, part of the new civil service reform law, later this summer.

Career employes who do not volunteer for the SES-the keystone of President Carter's plan to reform the federal bureaucracy-will not be punished for choosing to remain in jobs with greater security, but less chance of transfer or reassignment. But it has been made clear to them that higher pay, leave benefits, educational breaks, improved retirement, promotions and the good will of their political masters will be reserved almost exclusively for SES personnel. They will be the new elite of the government management team.

An estimated 9,200 federal executives-both career and political-may be brought into the SES. Incumbents in Grade 16 through 18 jobs have a one-time option to join. But a person moving up from Grade 15 in the future must join the SES, if his new job is part of it.

The results of the FEL survey are interesting on several counts. First, they are the only indication the government now has as to feelings about SES participation.

Office of Personnel Management officials say they have no solid material to show how many executives will come into the SES or stay out in the cold. They have predicted all along, naturally, that all smart, right-thinking executives will jump at the chance to serve in the SES. But they say they have no indications as to widespread sentiment on the SES.

Federal Executive League sent out questionaires to 5,200 executives whose jobs it identified as probably coming within the new SES. About 20 percent responded, and FEL believes it got a good cross-section of grades, jobs, geographic areas and agencies.

The study shows 62 percent of those who answered saying they definitely will join the new service; 12 percent definitely will not and 22 percent undecided.

The major attractions of the SES are "chance for higher salary," followed by the lure of 5-figure bonuses, and more leave time.

Sixty-five percent of those answering said their primary worry about the SES-which gives political managers much greater control over the people-side of their agencies-is "concern about political abuse." Others are worried about the new emphasis on mobility, being forced to move from jobs they know and like, or to different agencies or cities.

Only a handful said they have been subjected to "improper influence" from anyone to join the SES.

Full results of the questionaire will be handed out Saturday at an FEL meeting (1800 G St NW.) beginning at 8:30 a.m. Nonmembers are invited. The main topic will be "Federal Pensions and Social Security" with Ronald P. McCluskey, staff director of the subcommittee on compensation and employe benefits headed by Rep. Gladys N. Spellman (D-Md.).

The prospect of mandatory social security coverage and the coming impact of the new executive service are of prime interest to top federal managers. Most are pushing or past 50, nearly all are eligible to retire within 10 years. The last few years of their careers, and the shape and size of their promised pension checks, seem pretty important now.

Should be an interesting session Saturday, with a pension-promotion-or-perish theme. FEL's number, for reservations or information, is 632-7316. Ask for Lewis P. Jones.