Based on a cool little theoretical design I came up with. Gold has been picked due to its low melting point, so it will melt into the fuel disposal chamber easily. A meltdown state can be induced by pouring BVBR into the core shafts.
If the POLO depletes, you can use a portal out to dump it, then portal in more. Planning to automate the process at some point. Also this save is almost fully destructible!