144. The carrier shall ensure that:
(a) any group of packages, overpacks and freight containers containing fissile material stored in transit in any one storage area shall be so limited that the total sum of the criticality safety indexes in the group does not exceed 50;
(b) each group shall be stored so as to maintain a spacing of at least 6 m from other such groups; and
(c) where the total sum of the criticality safety indexes on board a conveyance or in a freight container exceeds 50, as permitted in Table IV of the Sixteenth Schedule, storage shall be such as to maintain a spacing of at least 6 m from other groups of packages, overpacks or freight containers containing fissile material or other conveyance carrying radioactive material.