So my friend an i were setting up a fission reactor and as we were looking at what we could use for coolant, my friend had seen that you could use sodium in the mek wiki, but when i looked at jei in game, i didnt see sodium as a coolant. just wanting to know if you can use it or not

I'm fairly certain you can use Sodium as coolant:

https://www.youtube.com/watch?v=8HwhqPjIllE
https://www.youtube.com/watch?v=yQzm5Ou5Bps

YouTube

Minecraft Mekanism Sodium Cooling tutorial

In this video I go over the Sodium cooling setup.Mekanism Mod: https://www.curseforge.com/minecraft/mc-mods/mekanismMekanism Mod creator Patreon: https://www...

YouTube

Surviving With Mekanism v10 :: E18 - Sodium Cooled Fission Reactor

Today we set up a sodium cooled fission reactor, which uses sodium as the coolant and produces superheated sodium that goes into the thermoelectric boiler to...