UPDATE statement with NVL in where clause

My update statement wont seem to finish its session with I use NVL in where clause.

   OPEN C_CHK_ERR_UPD;

   LOOP

      FETCH C_CHK_ERR_UPD BULK COLLECT INTO LP_item LIMIT i_commit_max_ctr;

      EXIT WHEN LP_item.COUNT = 0;

      FORALL i IN 1 .. LP_item.COUNT

         UPDATE xlll_st_item_master

            SET processed_ind = 'E'

          WHERE nvl(item, 'NA') = nvl(LP_item(i), 'NA')

            AND processed_ind = 'N';

      COMMIT;

   END LOOP;

   CLOSE C_CHK_ERR_UPD;