I've done Tritium Steel in my mod ;)
It's named Solid Steel in game, it's very cheap and much durable also. Only 6 times lighter than Obsidian!
It can be made with an easy way:
Components: 1xC - Coal, 1xT - T2O Ice (ID 514, item), 1xIO - Iron Ore. (working also for Charcoal)
It's a shapeless recipe.
Then, Half Tritium Steel has been crafted. Now it's only for smelting, and here we have - a Solid Steel.
1 block of this steel can be crafted into 4 Solid Steel Ingot, and vice versa - 4xSSI -> 1xSS.
For now, there are only tools which can be crafted from SSI. Just put this steel ingot instead of Iron, Diamond etc.. I'm working on Solid Steel Panoply.
New tools are about 2x more durable than Diamond Set, and much faster. It's enough, when You click once time on Netherrack with Pickaxe to extract block.
Tomorrow will be more City Stuff Mod features.