S.T.A.L.K.E.R.: Shadow of Chernobyl Message Board  

But as far as the grenades go, as soon as you walk into the lab, go left (where the fire doesn't get you) and in the very last cabinet, there are 2 boxes (and 1 on top). Shoot them, and you won't be disappointed. Lots of ammo and about 5 'nades.
-AOOS

On the topic of copying from other games:

It's hard to come up with new ideas. However this game was in the works since like 2001. That was before these games were released. S.T.A.L.K.E.R. > Half-Life 2, F.E.A.R., etc COMBINED.