You will need to add current limiting. The boost topology is not protected against a shorted output.
Regarding the inductor current rating, if the average inductor current is 9 A, then the peak will be greater. But, not 18 A if continuous conduction mode is used. The double value occurs if boundary mode is used. With a large enough inductor value, with 9A average, the peak can be 12A, while the valley can be 6A. As the L value increases, the ripple decreases, i.e. 11A peak w/ 7A valley, etc.
Since the duty factor will exceed 50%, instead of a 3845, use the 3843. It is identical in all respects except there is no toggle flip-flop which limits duty factor to 50%. I'd use the newest CMOS version, the UCC28C43 part. Have I helped?