I don't know how many records are involved, but NOT EXISTS might offer some advantages.
FROM V_RPT_TRANS2 WHERE INTNL_PF_NUM NOT IN (SELECT INTNL_PF_NUM FROM V_RPT_TRANS1)
Gail is right - looking at the plan would be your best way to troubleshoot. And you probably might have a look at why duplicate records seem to be creeping in.
It also looks kind of like a data dump. Reveiwing the requirements to see if some columns / rows could be eliminated also might be a good idea.