scram

local comId = os.getComputerID()
print("My Id is " ..  comId);

redstone.setOutput("back", true);
print("Reactor enabled");

while true do
    local id, message = rednet.receive()
    if (message == "SHUDOWN") then
        redstone.setOutput("back", false)
        print("Reactor disabled");
    end
end