Ah, like the grenade adept from the fiction near the end of Run & Gun? That was badass. And terrifying.
As others have said, it's an expensive idea. You need to budget your grens or else you'll be out of money fast.
A dwarf/ork Adept can be very effective with throwing weapons. I'd suggest a few throwing knives for times when you just don't want an explosion or someone isn't worth the money (why waste a grenade on a ganger when a throwing knife will get them to leave you alone?). You definitely need Gear Access on your armor like Hobbes suggests. Throwing knives also work for when it's just one or two opponents left. Again, it's about budget.
Adept powers can make you more flexible too. Missile Mastery is great for saving money... Ask your GM if he'd allow you to count hitting someone with the grenade as an improvised thrown weapon, and then having it go off from the impact (if it's motion sensing). The downside being it'd take more than just 3 hits to get it where you want it-- If you miss the opponent, you roll for scatter, no matter how many hits you had. That's how I'd rule it.
Nimble Fingers, Rapid Draw, and maybe one or two other powers would also be helpful (beyond the obvious of Improved Ability).
Grenades are quite varied on what they can do. A gas mask or armor with chemical seal can mean a CS or Pepper Punch grenade can be great. HE grenades and frag grenades can take care of drones and people. Flash-bangs are great for taking out groups non-lethally-- That they have no damage fall-off means it's perfect for certain situations. Doing things like throwing a grenade into a room of hostiles is perfect for making an entrance too, even if it doesn't do much (like a frag into a widely-spread group of armored targets).
