Export backup getting failed

Hi Team,

             Export backup getting failed due to below error. The mentioned table has LOB.

ORA-31693: Table data object "INST1_TW"."PR_ADDTL_DATA" failed to load/unload and is being skipped due to error:

ORA-02354: error in exporting/importing data

ORA-01555: snapshot too old: rollback segment number 32 with name "_SYSSMU32_3387151492$" too small

Undo retention for the database = 12700

select max(MAXQUERYLEN) from v$undostat;

MAX(MAXQUERYLEN)

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

            3352

Undo tablespace size 10gb..

Not sure how to proceed further.

Regards,

Ram.