Reinforced Blocks

Reinforced Stone is your upgrade to improve your base defense.
It is 250% more blastresistant than obsidian and provides you with an almost witherproof area.
Withers can destory these blocks only if you punch them into them. Their explosions are save.

Nukes are usually to weak to destroy any of those blocks, configs might change that thought.
For a Nuclear Reactor you need a wall at least 2 thick to be safe.

Reinforced Stone can be created in 2 ways.
You can either craft it out of 1 Advanced Alloy and 8 Stone
or you spray CFoam on a Reinforced Scaffold.

Reinfroced Stone is luckly not your only option to stay safe.
Industrial Craft Classic has imported a mod that gives you 2 different decorative options:

• Reinforced Stone Brick which is tiled Reinforced Stone
  
• Cracked Reinforced Stone which is a broken version of Reinforced Stone
  Both that can be crafted in the crafting table.
  

To round out the Reinforced Blocks there is also Reinforced Glass. It is made with 7 glass and 2 Advanced Alloy which is also 250% stronger than obsidian but it is seethrough. That can be fancyfied into Clear Reinforced Glass which has less texture in the way and allows you to see through better.

You have stone & glass but what about an door? That exists too. The Reinforced Door is basically your matchup to Reinforced Stone/Glass which can be made out of 6 Reinforced Stone in a door shape allowing you to get your explosionsave door.