I was testing reactor builds in creative single player and stumbled across a wierd case of temperature fluctuation. The build I used was 14x14x3 (interior 12x12x1), one layer of gelid cryotheum (added by @draknyte1/GTplusplus. The code is directly lent from Thermal Expansion) at the edges and the rest filled with fuel rods, two coolant ports, two access ports and a controller. The water was fed in by Pressure Pipes at infinite rates. The steam got dumped directly to an Extra Utilities fluid trashcan. In the end I noticed that the temperature stayed most of the time at 197-198 but every couple of seconds or so jumped up to ~260 which also affected the fuel consumption because of the lowest temperature treshold was broken.

Initially I built a smaller reactor and expanded it using Extra Utilities builder's wand. The Reactor was located at a four chunk intersection with atleast a few fuel rods in every chunk but I didn't leave the area so it shouldn't be a matter of chunk loading/unloading. Both coolant ports were within one chunk (one configured to input and one to output) and the access ports (one filled with yellorium ingots and one configured to output cyanite) & controller in another. The port configuration was made using an Applied Energistics wrench. All of the fuel rods were configured to 94% inesrtion to reach a stable ~2,1k steam per tick while maintaining the temperature at under ~197. I tried replacing the coolant with diamond blocks (stabilized the temperature) and then back to gelid cryotheum (started fluctuation again. this could indicate that the issue might be also related to either fluid coolants in general or gelid cryotheum).

Lastly I tried closing the game and restarting and the fluctuation persisted. Only after I changed the fuel rod insertion back and forth the fluctuation stopped. No matter what I have tried I haven't been successful in reproducing this wierd phenomenon since. For reference I tested other similar reactor builds with temperature bouncing between 199-201 and breaking the 200 treshold did not cause such a notable increase in temperature.

Versions:

• Beyond Reality pack 2.4.2-r2
• Big Reactors 0.4.3A
• GT++ 1.4.9
• Pressure Pipes 1.3.0.131
• Extra Utilities 1.2.12
• Applied Energistics rv3-beta-6

Please read #583