Understanding the usage of version store in tempdb
There can be many reasons for that.


You're queries run and generate a version, during another query use the same tables. During this phase version 1 will be hold back. If your transaction isn't commited at the end, it may occur that version 1 will last for a long time in your tempdb. Make sure that all transactions are probably commited and closed.
Make sure that all information is stored on the disc. It may occur that your information is still stored in your memory. This could cause the hold of a version in your tempdb. You can force the latch process by using CHECKPOINT after your commit.


Hopefully this will help you.