High school asemblies are notorious for breakdowns in discipline, and last week's gathering of seniors at Mount Vernon High School in Fairfax County was no exception.

"This is worse than usual," one teacher muttered as students talked and laughed among themselves, ignoring the woman on stage with a microphone.

The reason for the assembly was an attempt to make voter registration easier for area young people. Fairfax County registrars last week began a swing through 20 high schools where they conducted mass voter registration.

Following a discussion of the electroal process, seniors could fill out registration cards. When the paper work was complete, Fairfax County general registrar Eve Newman asked the group to stand, raise their right hands and repeat the oath administered to every new voter.

By the end of the first day, county officials had registered nearly 500 new voters.

"I think it went very well," said Newman gamely as the last of the students left the auditorium. "The kids just have a lot of energy."

Newman's generosity toward the students, some of whom had given her a healthy dose of inattention, was not shared by other assistnat registrars. When asked for a copy of the high school itinerary, one said: "I just burned it."

A random sampling of the newly registered voters did not show partisan politics to be of primary importance. Most students said they registered because the opportunity was there. Few were supporting political candidates and most said they were unsure if they would vote in November's presidential election.

County residents wishing to register may do so at any of the following mass registrations for students.

Today: Oakton High School at 8:45 a.m.; Woodson High School at 8:45, Lee High School at 8:50.

Friday: Jefferson High School at 8:55 a.m.; Stuart High School at 9:45.

March 24: Hayfield Secondary School at 8:30, Fort Hunt High School at 10; Chantially High School at 9:25.

March 25: Edison High School at 9:15; Falls Church High School at 8:40.