External lava heating effects?

Does anyone have any reliable information on the heating effects of lava external to the reactor? The reactor planner app will drop external cooling to 0, but does external lava ever offset the internal cooling?

I'm trying to find something to make it easier to keep my neutral breeder hot, so that it's actually worth running. Manual heating with lava buckets is ridiculously impractical, switching out configurations is viable, but vulnerable to timing failures on the operator's part. Maintaining sets of hot components sounds like there are many possibilities to really screw up your reactor. The hope was that I'd be able to use a lava bath to prevent the reactor from cooling down, but it seems like this is a bit of a pipe dream.

I'm guessing that lava will help slow down the cooling process, but can't balance it out?

Well, after some testing tonight, I can say that lava doesn't/can't do anything to offset the internal cooling (which I imagine is true for balance reasons). It does, however, significantly reduce heat-up times (especially if additional uranium is used to boost heat production) and drastically increases cool-down times, which helps you hold onto the heat you've gained more effectively, especially while away.

I'm using a one-uranium, two-isotope reaction with four chambers, three IHDs, 7 coolant cells . The 3x3x3 volume is divided into four lava/air spaces and ten air/water spaces (of which, only 9 get water during operation, the last is air at all times). This setup means that with both insufficient internal cooling and negated external cooling, we get up to heat fast. When we approach our target heat level, we shut off and clear the lava space (piston to block flow, four pistons to revert the lava to air right away). We do this at 9000 degrees. At this point, we now have partial external cooling (the 14 air blocks and reactor hull cooling are no longer being negated by lava), so we heat up more slowly. Once we reach 9500 degrees, the water is added. I've seen stable temperatures at both 9501 and 9502 degrees for this setup, with three or four different heating cycles.

To accomplish this, I am using the Nuclear Control add-on by Shedar. Two remote thermal monitors are used. One at 9000, to shut off the flow of lava and, after a short delay, pulse the clearing pistons; the other at 9500 to release the water, which stabilizes the temperature, forming an equal breeder.

This may not be the most accurate measure, but for comparison, note the difference in cool-down time between with lava and without. This design may not be the most efficient ever devised, but (with the add-on I mentioned to control it), I believe it is fairly safe, very easy to run, and relatively productive, especially after the initial heat-up period.

That's not a bad design if the primary goal was heat maintenance. I guess my main goal would be better stated as, "creating a mostly self-maintaining system, requiring minimal human interaction for safe operation over an indefinite period of cycles." The secondary design goals include rapid heat gains when starting, slow heat losses when idling, and exactly neutral heat while running.

I do find it a bit strange to use two uranium fuels to recharge two isotopes. Obviously, the yield would be a little higher than that, but I have a sneaking suspicion that the uranium profit margins from running that thing are going to be a fair bit lower than they are with the setup I posted. I'm not sure how the planner is calculating the breeder efficiency, but mine scores a 2 of 3 while your design achieves 1 of 2. Certainly not a bad design overall, and ingeniously accomplishes the goal I originally asked about. Sorry about the moving target there!

Thanks!

That is basically the design I ended up with (see my second post in this topic )! Yours does have better heat retention characteristics, though (3 internal cooling compared to my 7). I wonder if your design allows for separated lava and water spaces? I was worried about possible water/lava collisions affecting things despite the fact that I am using pistons to clear the lava after the flow stops.

Seeing your design with its excellent heat retention characteristics makes me wonder what other improvements I can squeeze out of the lava/water design class.