The forum banned my main account accidentally, so I had to post on an alt one. Basically I copied a design off the reactor design thread (http://www.talonfiremage.pwp.b…6ucaceovy6uixc92gxt2grpxc) which is stable according to the planner.
Ingame is a different story. Instead of running at 0 heat, it runs at 32 for some reason. It does output the correct EU/t (300) so I didn't think much of it, but I came back a few hours later to find it had shut off via the thermal control. The Heat Exchanger in the bottom right, and the heat vent to the left of it had both melted. I tried to recreate in a creative world, and sure enough you can see the exchanger durability dropping as the reactor runs.
In short, why doesn't this design work?? I am not using MOX fuel in this, everything is exactly as the design above shows (yes, I triple checked the components).
Also as a side note, I tried the design in FTB Mindcrack pack (1.5.2) using the GT computercube, and it runs completely fine, as expected. The GT computercube is broken in my 1.6.2 version and I can't use it to test builds. I've had multiple people tell me the "vanilla" reactor mechanics had not changed in ic2 experimental as far as heat/eu, so does anyone have the knowledge to explain to me what the problem is here? Thanks a bunch.