This is something more you need to discuss with your site support group as there may be standards and procedures already in place. Data sets on tape can be deleted just like any disk data set, but there are some additional things to be aware of. For example, if the tape data set was created with an expiration date, simply uncataloging the tape data set won't delete it. Your tape management system will usually maintain the tape until it is either explicitly deleted or the expiration date is reached. If the tape has multiple data sets, all of them have to reach expiration before the tape can be returned to the scratch pool.