I just finished an ice-cooled nuclear reactor in creative, ssp. I filled the reactor with uranium cells, except for the outer edges of the chamber, making something like this:
where [] = ice and u = uranium. It is a 6 chamber reactor, and it has water all around it except for directly underneath it (where I'm sending my power) and about 3 blocks where I have a shut-off switch. I monitored the heat for about 3 hours, and it stayed stable, since I was generating more ice than the reactor was using up per second. So I move the build to SMP, and twice the reactors have exploded, both time while I was offline and nobody was around to load the chunks. The first time I figured I had done something wrong, but the reactor went for two full cycles before it exploded. This time, with the same build, I built it, watched it for an hour, logged off for another half an hour, and when I logged back in, crater. It seems that something happens when I log out to increase the rate that the reactor heats up. Any clues as to what is happening?
I made a post but deleted it out of frustration. I was manually putting ice in but the redstone must be the cause of the issue 