The Nuke is similar to TNT, but has a much higher explosion radius, comparable to a Nuclear Reactor meltdown. Nukes are so powerful that they can penetrate through Gem Armor, Red Matter Armor and Dark Matter Armor.
Walls composed of Reinforced Stone and Reinforced Glass will minimize the damage of the Nuke, but the walls should be at least 2.5 (effectively 3) layers thick to completely protect anything behind. A Nuke will even destroy Obsidian, as the blast resistance of Obsidian has been reduced to 60 in Tekkit. The only things that can survive a nuclear explosion are Bedrock, End Portal, Enchantment Table, dark matter blocks, red matter blocks, force fields, and personal safes (on slower computers, Nukes may blast through and/or destroy Forcefields ). Although the Dark/Red Matter Blocks and Personal Safes don't take any damage from the explosion, they will allow the blast to pass through and damage items behind.
The blast radius of a Nuke is dependent on the blocks surrounding it. Underground, it will generally have a blast diameter of 20 blocks (10 block radius). Above ground in the open it will have a blast diameter of 76 blocks (38 block radius, however low blast resistance blocks can be damaged up to ~130 blocks). The player, if standing directly on the nuke and completely protected, will be launched 191 blocks into the air.
The Nuke is usually turned off by default on Tekkit servers, to prevent a substantial amount of damage from being caused so easily. Older machines or clients with a small amount of memory are not recommended to detonate over 5 nukes at once, as the crater usually creates a large amount of memory usage (lag), while the client redraws the world. Some computers can't even handle 1 Nuke, which can result in not even being able to close the game and having to restart your computer.
You can ignite a Nuke with a Redstone signal, or with Alloy Wire (must be left-clicked with Flint and Steel instead of right-clicked). The fuse time is about five times as long as TNT , being approximately 13 seconds. Although it is possible to escape damage or death by running away from the Nuke, it is best to have a long line of Redstone or Red Alloy Wire, because the blast radius of a Nuke is colossal. At the end of the Redstone trail from the Nuke, you can simply place a Lever or a Redstone Torch to activate its core. Fire will not set off a Nuke; only a direct Redstone signal, a lever adjacent to it being switched, left-clicking it with Flint and Steel , or another explosion (such as another Nuke, TNT, Industrial TNT or Dynamite with a Dynamite-O-Mote (so that it can be used remotely) will ignite a Nuke.If a Nuke detonates near another Nuke the second Nuke will have a shortened fuse.
If Nukes are placed in a column from bedrock to the surface and then detonated (in any order), within 10 to 15 seconds the game may become unplayable even after the world is redrawn (game slows to 2 Frames Per Second maximum - tested multiple times). This may cause a crash on servers with only moderate hardware available. However, 60% of the time, after leaving the world open for a half hour or more, the dropped blocks that cause the lag will de-spawn and the lag will diminish. If you get more than one frame per second, your world will be saved. (Tested 11 times, each with 20 nukes.) However, if drops are disabled in NEI, lag will be avoided as the computer only has to redraw exposed areas, instead of dealing with the dropped items.
To remove excessive drops in SMP:
- Keep away at least 200 block (10+ chunks) from the nuked site
- Use command /remove item 500. This will destroy all drops in a 500 block radius.
- The Nuke still causes block damage if it is in a water current, even though TNT does not.