TempLog.ldf Grows Too Large
You can observe transaction log usage in Tempdb with DMVs, and then possibly instrument your procedure and monitor its transaction log usage in tempdb to see if you can account for the log file growth and possibly identify what's contributing to it.

EG:

select database_transaction_log_bytes_used /1024. log_mb_used
from sys.dm_tran_database_transactions dt
join sys.dm_tran_current_transaction ct
  on dt.transaction_id = ct.transaction_id
where database_id = 2