Fairfax County parents, meeting with school officials Saturday, were divided over whether intermediate school students should be admitted to a high school opening next fall in Chantilly.

Officials have recommended opening the building, which has the temporary name of Braddock Park, with about 600 ninth and 10th graders drawn from areas served by Chantilly and Fairfax high schools. They would add about 300 seventh graders the next year to relieve crowding at Rocky Run Intermediate School. Under this plan, these would be the only intermediate school students enrolled.

Under this plan, the school would become a senior high with grades nine through 12 and approach its rated capacity of 2,000 students by fall 1991.

During and after the meeting, parents from areas now served by Fairfax High called for two full grades of intermediate school students at the new building. Parents from areas served by Chantilly criticized the proposal for including any intermediate students.

"To have grade gaps within the school is ludicrous," said parent Lee McFann, one of about 200 people who attended the 8 a.m. meeting. "You've got to look at the social aspect . . . . I would like to see {grades} nine to 11 {next year}. It's the same maturity level."

"A child who has started high school deserves to finish at that school," said Fairfax High School PTA member Judy Buchanan. She said she plans to organize parents to push for opening the school with grades seven through nine, avoiding moving students already enrolled at a high school.

Some parents criticized the plan for including only two grades of students to start -- too few, they claimed, for healthy extracurricular activities and advanced academics, despite administrators' assurances that they could provide a full range of courses and activities.

"A lot of things got out on the table that showed there was no consensus in the community," said Roger Webb, facilities planning director. "I don't think there's any way we can satisfy everyone. We can't open it all which ways . . . . I thought it was a very helpful meeting. I hope it was helpful to the community."

He said that as a result of parents' comments, his staff will examine other options, including opening the school with grades seven through nine and sending some Clifton students to Robinson Secondary School.

Webb said on the subject of including seventh graders at the new high school:

"We have opened a number of schools in that fashion. The county has three secondary schools. I firmly believe that with good leadership and appropriate supervision, that need not be a problem. I can understand parents' concerns . . . . It's like sending your child to the first day of kindergarten.

"It was done with the opening of Robinson. The seventh grade was housed at Fairfax for a year and seemed to be well contained."

Parents of Chantilly High School students said they remembered drug and discipline problems among seventh and eighth grade students when Chantilly included intermediate school students.

"I've lived through a seven to 12 {grade high school}. I don't think a child should be subjected to adulthood in seventh grade," said Chantilly PTA pyramid coordinator Gail Jasionowski. "It was like I went from a kindergarten class to a high school overnight."

In Clifton, where students are bused for up to an hour to get to Fairfax High and Lanier Intermediate School, parents are eager for the new school to include intermediate students.

"We want to get as many students from Clifton in there as possible," said Trudy Larson, past president of the Clifton Elementary School PTA and a spokeswoman for parents there. "This school that is being built is our school . . . . I think we deserve this school because historically we have been a swing community. Whenever they needed some students somewhere, they threw us on a bus and sent us there. They owe us a sense of community after all these years."

Parents in other parts of the Fairfax attendence area, which would not be directly affected by the new school, also want intermediate school students at Braddock Park, but for the opposite reason. They hope to keep Clifton area high school students, who have a reputation as high achievers, at Fairfax to maintain their high school's enrollment and academic programs.

Larson said that her group will work with Fairfax City parents to push for intermediate school students at Braddock Park but that their interests would probably diverge when the time comes for choosing boundaries for the new high school's attendance area.

Superintendent Robert Spillane is not scheduled to make a formal recommendation for the boundaries until Dec. 17, but administrators have disclosed three alternatives.

One would include a roughly rectangular area in the southwest corner of the county, bordered by Braddock Road between the Loudoun County line and the intersection of I-66 and Rte. 28, then Rte. 28 south to Lee Highway, from there east on Lee Highway to Clifton Road, south on Clifton Road to Popes Head Road, and from there following the boundary of the Clifton Elementary School attendance area south to Prince William County.

The second would eliminate the western tip of the first and split the Clifton attendance area down the middle, along Wolf Run. It would add a section to the north, including Xanadu Estates and Sequoia Farms. It would be bordered by Cub Run in the west, Flatlick Branch in the north, Rte. 28 south of the Flatlick Branch to Lee Highway, Lee Highway to Clifton Road, and Popes Head Road to the Wolf Run River.

A third would resemble the second but include the entire Clifton area and remove a triangular area in the northwest approximately bounded by Poplar Tree Road, Braddock Road and Rte. 28.

Each proposals has a corresponding proposal for the seventh grade class, which would be drawn from areas served by the Lanier and Rocky Run elementary schools.

The administration projects the first proposal would do the least to reduce crowding at Chantilly High, where 2,600 students now use a building designed for 2,300, but it would still reduce the student body below rated capacity within five years.

The first proposal would have a large projected effect on Fairfax High School, reducing the student body to 1,463 by 1992. It would split the Country Club Manor and Chalet Woods communities along Braddock Road.

The second proposal would have the smallest effect on Fairfax High School, leaving the student body at 1,596 in 1992. It would have the greatest effect on Chantilly High School, where the student body would fall to as little as 1,589 in the 1990-91 school year. It would split Clifton Elementary School down the middle.

The third plan would have the same effect on Fairfax High School as the first plan, and it would have a moderate effect on Chantilly's enrollment. It would keep the Clifton Elementary School area in the Braddock Park area but split the London Towne Elementary School enrollment area in two places for high school enrollment.