From a mechanics point of view, do the holes in your reinforced shielding (for power and redstone cable) compromise the shielding aspect at all? Is the blast contained, partially contained, or is the full force directed out the hole?
I did a before and after test, so I think I know the answer - so wiring up from the bottom is probably best? Full containment not possible?
It is possible, and my design incorporates it.
I don't know if you want to figure it out yourself or just have the answer, so I'll give you a clue, and then the answer in the spoiler. Also, do not build shielding in the 5x5 around the reactor, it will melt and stop providing the same absorbtion.
Hint: In minecraft, explosions happen as lines drawn outward from the central point, and are absorbed by things in that straight line.
Lol ok - trade secret? 
And is it done without wireless redstone rcvr and teleport pipes? Or does one make a shielded tunnel out of the reactor core? (in other words the meltdown blast doesn't go around corners).
My reactor uses almost exclusively IC2 & vanilla parts, though I do have an EE alchemical chest instead of a vanilla chest for more space. I do not have a pipe into it, it is six chamber.
I have not tested this by exploding the reactor, as I am playing it SSP hardcare and don't want to die, but it should in theory provide total containment of all but extreme urainium filled combos that I can't use anyways because I dont have logic pipes. Every line from the center must go through 3 reinforced stone minimum (top and bottom too). Add another layer of stone and it should work even then in extreme cases.
Hint: In minecraft, explosions happen as lines drawn outward from the central point, and are absorbed by things in that straight line.
Perfect, thanks this clears it up.
Whats the distance you would need from the reactor so it no longer can destroy reinforced stone?
The melting to lava thing happens at 85% hull temp in 5x5x5, so I don't build shielding there. Realistlically, it doesn't stay there long, as 100% of heat generated is going to hull by that point, all heat dispensers will have melted. Chances are low that everything would melt, but since I don't know what will and what won't I don't build anything in the 5x5 that I don't expect to melt.
If you are talking attenuation of the explosion in general, that depends on what it goes through before hitting the reinforced stone. Using http://www.minecraftwiki.net/wiki/Explosion as a reference, this is what I get.
If it's going through air, you'd have to solve this:
Miniumum Block resistance = ((1.3 × power - attenuation steps × step length × 0.75) / step length - 0.3) × 5.
for attenuation steps
whre the block resistance 150 must be > or = minimum block resistance
Where step length is probably 0.3
and the power of the explosion is not something I know
so the maximum attenuation steps for
150 > ((1.3 x power - attenuation steps x 0.3 x .75) / 0.3 - 0.3) x 5.
which simplifies to
attenuation steps >= 5.778 * Power - 40.4
but still need to know the power of the explosion, I don't.
edit: Nukes don't use minecrafts explosion code, apparently. Trial and error!
IC nuclear explosion don't use normal explosion code.
For all of the "holes" in the shielding, I make a block of reinforced stone just past the hole to catch the explosion. I have not blown up any reactors yet though, so I can't say if this actually works.
Roughly:
I'm going under the assumption that explosions can't do right angles very well and will waste most of their energy against the stone.
QuoteI'm going under the assumption that explosions can't do right angles very well and will waste most of their energy against the stone.
They can't... tested this with other mod blocks as well
with 1.70 out you can now turn cables into construction foam which have nice blast resistance. so it helps contain explosion.
If you have a massive amount of resources you can do simply make double layer of reinforced stone.
Another way is to use wireless redstone, so you dont have to break through the shielding for the signal, then just have the wires move upwards from the reactors and make a room over the water.
After all, more shielding is better, than trying to be efficient, you most definitly want to avoid another Fukushima!
Pffff...
Just ignore the shielding and pretend that you constructed a totally save reactor. But if you really want shielding it is also a cheap solution to use Construction Foam, its not the best, but it's cheap. And you should use Construction-Foamed Cables, this also increases the shielding.
IC nuclear explosion don't use normal explosion code.
This.
As well i'm not 100% sure whether foamed cables actually have the same explosion resistance as CF.
I always "snake" my cables and walkways.
wait... does this mean my single layer reinforced stone will fail?
I have the reactor in the middle of an 5x5 area, on the 6th row, i have reinforced stone. the only hole i have is the area coming from under it for wiring. walkway has a reinforced door.
I know it wont blow up. but i like to feel better that knowing that if it does, it would be contained.
wait... does this mean my single layer reinforced stone will fail?
I have the reactor in the middle of an 5x5 area, on the 6th row, i have reinforced stone. the only hole i have is the area coming from under it for wiring. walkway has a reinforced door.
I know it wont blow up. but i like to feel better that knowing that if it does, it would be contained.
Yup, you need a minimum of two layers unbroken for explosion shielding. (by "unbroken" I mean extra around places like cabling and such)
three to be safe/paranoid, two sometimes does a little damage to the environment.
