Three Portsmouth students were officially expelled from Portsmouth Senior High School by a vote of the Board of Education Monday night. The action followed an incident at the school Jan. 5 when a bomb exploded and police iden tified the trio as being responsible. The three are Jeffrey S. Chidester, 17, 87 Sims Ave., Richard G. Garrison, 16, 1240 Maplewood Ave., and Steven R. Moody, 16, 12 Walnut Ave. The board, meeting in executive session with the parents and High School Principal William Mayo, voted its approval of a recommendation made by School Supt. Timothy Monahan dismissing the three from school for the remainder of the year. The recommendation made by Monahan said that ‘“‘due to the gross misconduct of those named students,’’ dismissal is recommended from the Portsmouth school system for the remainder of the year. It further recommended a ‘‘review of the case prior to the 1979-80 school year,” at which time the parents ‘‘or their representatives may present to the board any information they deem important to the case” and the board will then decide ‘‘whether to continue the dismissal or allow the students”’ back in school. The students face charges equivalent to that of arson in an adult court, and a preliminary hearing has already been held. Two of the three, police have said, have been linked to a bomb dropped from a window at the school Feb. 15. Another incident involved an unexploded bomb found on stairs at the school Jan. 4. Garritson and Moody are currently at the Youth Development Center in Manchester, while Chichester has been released to the custody of his parents. In other business, the board approved a policy concerning alcohol and unauthorized drugs on school grounds or in any school. High School Principal Mayo urged that there “be no loopholes in the policy for outside groups,”’ giving the policy ‘‘much more teeth and all-round protection.’ The policy which passed says that alcoholic beverages and-or unauthorized controlled drugs aren’t permitted in any school or on school grounds or school buses. Monahan said the policy was needed after meeting with the police, who suggested it because nothing can be done to prevent someone 18 or older from coming onto the property with an alcoholic beverage. BOMB TRIO Please Turn to Page Three Big news Israelis examine Tuesday morning paper with report of President Carter's trip to Egypt and Israel this week. With labor troubles at Israel radio stopping most news program, Israelis looked to newspaper for information on Carter's latest bid to reach a treaty between Egypt and Israel.