Students at the University of Virginia have voted to continue the "single sanction" honor system that has governed the school since 1842. The system provides for one penalty, expulsion, for students found to have violated the school's honor code.

In two days of voting on a referendum proposal to soften the penalty for first offenders to suspension, 3,216 students voted to keep the old system and 2,670 favored amending it. Six other attempts to change the code have failed in the last decade.

"This puts the question to rest for quite a few years," said Nancy Lyons, chairman of the university's honor committee. " . . . Tonight is a visible sign that the students do support our system." The code is administered wholly by students.

Critics of the system argued that the harshness of the expulsion penalty means that students are reluctant to enforce the penalty on one another and that lying, cheating on exams and theft go on unrecognized at the university.

Its supporters said the single sanction was the backbone of a system that had long worked well. Its severity, they said, ensured that no trivial cases would be brought and that student jurors would deliberate carefully before convicting.

Even though the university has more than doubled in size to about 16,000 students in the last 15 years, students still are usually left alone in classrooms for exams without proctors or allowed to take test questions home. Dormitories are generally unlocked, and most local merchants accept student checks.