10 years tape retention

hi

we have oracle RAC databases which are backed up to asm disk and kept for 14 days.

we have requirment to keep 30 days backups onto data domain ( disk )

and 10 years offline on tape.

question is in above setup how can i copy 1 backup each month from asm or storage unit to tape ?

i am thinking of creating additional storage unit , and additional rman job which runs each month to send data into new su.

we then copy whole storage unit to tape and delete all files.

is there better way to do this ?

thanks