I can safely say if you launch 7 days and it immediately starts using 14gb of ram, there's something wrong. Mine only uses 1.1 GB working set and 2.9GB commit on launch.
If you mean after generating a new RWG, close and restart the game after generating a new world.
So, standby memory you're seeing is memory that programs frequently/recently use, it is not memory taken up and that cache is instantly overwritten if it's needed. That's completely normal, and is different from a "memory leak", and is actually Windows doing that to make your frequently used programs snappier/load faster.
Case in point, I had 21GB in my Standby. Loaded 7 days into a world, it ate up the Standby, exited the game, I am now at 15GB.