The Commission shall establish, by rule or regulation, a detailed system of reasonable and fair priority rights applicable to the sale of Government-owned property to private purchasers at each community. The priorities shall—
((a)) be uniform in each class or subclass of property;
((b)) give such preference to occupants and project-connected persons and to incoming employees of the Commission, of a contractor, or of a licensee as the Commission finds necessary or desirable, giving due consideration to the following factors:
((1)) The retention and recruitment of personnel essential to the atomic energy program;
((2)) The minimization of dislocations within the community;
((3)) The expeditious accomplishment of the disposal program; and
((4)) The desirability of encouraging private firms to locate or remain in the community;
((c)) give the occupant of a Government-owned single family house, and the senior occupant of a duplex house, at least ninety days in which to exercise the first right of priority;
((d)) permit persons who have formerly been occupants, project-connected persons, or inhabitants of the community, upon application therefor, to have such priority as the Commission finds to be fair and equitable; and
((e)) not impair any rights, including purchase rights, conferred by existing leases and covenants.