K3b blu ray not recognized

using suse leap 42.2 downloaded scientific linux 7.8 everything [8.1 gb] and got 9 gb dvd blank disk for burn, but k3b said needed blu ray, so got new blank single layer blu ray and inserted and again was instructed to insert a blu ray disk, so tried a different new blu ray disc and again was as if k3b simply couldn't see it [no specification that it needed to be a dual layer disc].
Does k3b need some special add-on for something like this?