Meltdown timing starts at 3,120 K. The community reactor guide says you then have four minutes to cool the core to 800 K or below, and that the SCRAM button unlocks about 45 seconds after 3,120 K. Another operations summary uses 900 K and a 45 to 50 second wait. Watch the in-game SCRAM prompt instead of arguing with a wiki number while the core is climbing.
Above roughly 3,300 K, or with cooling not at full output, the same guide says a save is unlikely. Above about 3,500 K it calls the explosion nearly unavoidable, and past 4,000 K it says the chance is gone. Call an evacuation on the radio if you are already in that range.
A successful save from a controlled SCRAM test pays 1,000 XP. An explosion pays less. The guide also says a Tier 3 power-order shift is usually more XP than SCRAMming for fun. Do not run a SCRAM test while West Noobian players are active. A rod jam, shown as ERROR instead of a percent, cannot be cleared from the panel.
SCRAM test, only with permission
Get a yes from the Shift Manager and Plant Director. Tell the other operators. Confirm coolant pumps on, feedwater on, water at 100 percent, external grid available, at least one generator running, and all four relief valves off cooldown.
- Rods to 0 percent and the coolant valve off.
- Around 2,200 K, lower rods to 20 percent, then return the switch to idle.
- At 2,700 K, lower rods to 95 percent, then idle again.
- Near 3,110 K, lower rods all the way to 100 percent.
- At 3,120 K, not before, turn the coolant valve on, confirm rods at 100 percent, and open all four relief valves together.
- Press SCRAM as soon as it unlocks.
- Keep cycling relief valves until the core is under the success line, 800 K in the long guide.
- Wait one to two minutes for the restart, then ignite again. Do not restart into a control room that security has not retaken.
Each relief valve drops 75 K over 10 seconds and then waits 90 seconds. All four together drop 300 K. They stack, so you do not stagger them. After the first drop toward about 2,800 K the temperature can rise again. That rise is described as normal if every cooling system is actually on.
If someone opens a relief valve before about 3,050 K, put rods at 55 percent, coolant on, and wait until every valve is ready before you continue. If a coolant pump or the water level fails, cancel the test: rods to 100 percent, coolant valve on, and all relief valves if you are already above 1,600 K.
Emergencies that are not a planned test
Hostile players in or near the control room. Radio a short call such as WN CR. Rods to 100 percent, all relief valves, grid to external. A colder core is easier to save. Hostiles can use rods, coolant, feedwater, and turbines. They cannot use Shift Manager controls or the ignition button.
Coolant pumps off. Rods to 100 percent, or about 80 percent if only one pump is down. Call Plant Maintenance or restart the pumps yourself. Cycle relief valves above about 1,450 K, and open all of them above about 1,600 K.
Feedwater level falling. Call maintenance, rods to 100 percent, turbine valves to 100 percent so they run as long as they can, and be ready for a trip. Move to the external grid if water keeps falling. If both pumps at 80 percent still cannot refill the vessel, warn maintenance and raise feedwater flow on the external grid.
External grid down and one turbine desynced. Switch to the turbine grid, put the synced turbine at 100 percent valves, keep at least about 1,400 K, and call repairs to the transformers.
External grid down and both turbines desynced. Switch to the generator configuration, keep at least two generators running, and stall the core if temperature is rising. The long guide says cutting the DC bus is optional here. Another note says generators already cover the auxiliary bus, so cutting DC is not required for cooling.
Stall at 323 K
A stall is the cold floor. It does not pay the SCRAM test bonus. Use it when the control room is being taken, when a raid is about to hit the SKALA computers, or when cooling will not stay on.
- Switch to the external grid, or to generators if external power is gone. Turbines will trip as temperature falls.
- Rods at 100 percent. Coolant valve and feedwater valve open.
- Use relief valves if you must drop faster.
- At 323 K, leave cooling open and rods fully in. Further relief valves do nothing at the floor.
During an announced raid the reactor cannot finish a meltdown while the raid notice is up. The moment the raid ends, an overheated core can melt immediately. Stall before phase two, when the city falls and SKALA computers start getting hacked. A hacked computer can disable the function it controls, including rods or relief valves.
Radio in the reactor guide is opened with X. A controls page instead binds the department radio toggle to Z. Use whichever control actually opens the radio on your client, and keep the channel for failures and attacks.