a radiation shielding system includes at a first shielding member and at least a second shielding member that is coupled to the first shielding member . each of the first and second shielding member includes a moderator material . at least the first shielding member includes at least one locking member extending from a surface of a region where the at least one locking member is disposed . at least the second shielding member includes at least one recessed area on a side of the second shielding member corresponding to the side of the first shielding member . the second shielding member is coupled to the first shielding member by the recessed area receiving the locking member .