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.