President Reagan's chief personnel adviser says a new plan to rifproof U.S. workers could result in more people getting canned, blocked promotions and transfers and perhaps a constitutional crisis in the bargain.

Donald Devine, head of the Office of Personnel Management, says a rif-protection package introduced last week by Rep. Mike Barnes (D-Md.) and 31 colleagues presents a "lot of serious problems, both constitutional and administrative," for the government. In short, he doesn't like the bill.

Barnes' staff says that Devine's fears are without merit. They suspect the real problem is that he doesn't want to have to sit down with unions, next time the rif winds blow, to seek alternatives to firing people.

The Barnes bill would require agencies facing rifs to first consider other ways to save money. If the rif was unavoidable, job openings those workers might fill would be frozen to give them first crack, before they could be filled by others.

Barnes' bill would have the General Accounting Office "certify" that agencies had met the bill's requirements before they could rif. Devine says that since GAO is an arm of Congress it amounts to giving the legislative branch "veto power over fundamental executive responsibilities."

OPM, which itself just finished one of the biggest rifs in government, says Barnes' plan to freeze openings-by-occupation for people on rif lists would unnecessarily tie up personnel actions and undercut its own "highly successful" programs to find new jobs for fired workers.

The arguments go on and on. Suffice to say the administration will not support the Barnes bill in its present form. The Barnes people say they are not surprised.