If only the Log File is corrupt you could try to attach only the Data File with:

sp_attach_single_file_db [@dbname=] 'dbname', [@physname=]'physical_name'

Example:

sp_attach_single_file_db @dbname='DataBaseName', @physname='C:\SQLServer\Data\DataBaseName_Data.mdf'

Edit :w00t::

you must Stop the Production SQL Server Instance in order to copy the mdf file to another location and attach to a Test SQL Server Instance.

Hope it help you