The petrenkos_workshop.zip file you have requested: Shadow of Chernobyl / Mods / Singleplayer / Petrenko's Workshop - 32.95kb is not available. Perhaps try browsing all files for the game S.T.A.L.K.E.R. Shadow of Chernobyl and upload any files you want to share or are missing. This is the only information we could locate:
A small mod which allows the player to bring weapons and armor to Petrenko of the Duty faction for upgrading.