Unaccompanied Children Pose a Refugee Problem
US officials resettling Vietnamese and Cambodian refugees have discovered more than 300 children, mostly Vietnamese, who arrived in US unaccompanied by parents; nearly all of children reptdly have parents who have not released them for adoption; serious legal and moral problems posed by presence of children explored; interagency Task Force on Indochinese Refugees chief spokeswoman Elinor Green says neither Internatl Red Cross nor UN's High Comr for Refugees have been asked to approach new S Vietnamese officials to determine whether children's parents want them returned to home country; UN spokesman says High Comr's office is aware of children's presence in US and has asked task force not to put them up for sponsorship; task force deputy sr civil coordinator in Camp Pendleton Thomas C Irvin says policy of not permitting outsiders to talk with children or visit dormitory is effort to shield youngsters from undue pressures; camp is housing about 170 children who have 'adopted' other Vietnamese families and add 13 girls and 20 boys who are being watched over by Red Cross officials; illus (L)