Long running insert

Oracle 11 Vanilla (no patches)

One of Developers started a script with 12 000 inserts. It is running now more than 55 hours consuming 100 % of one core. He tried to kill the session using:

alter system kill session 'sid,serial#' immediate;

I see following sessions:

  INST_ID    SID   SERIAL# SPID      BOX           USERNAME          OS_USER         PROGRAM              STATUS  LAST_CALL_ET_SECS SQL_ID

---------- ---------- ---------- ---------- ------------------------------ ------------------------------ -------------------- ------------------------------ -------- ----------------- -------------

   1     75     44432 4416      wce-728           ORCL          dev1            SQL Developer           KILLED       218063 b2bs2ns79qky8

   1     57     11763 20749      wce-728           ORCL          dev1            SQL Developer           INACTIVE        25014 b9pg8h112g2gv

I checked undo usage but do not see no output: