reactor refiller

reactor = peripheral.wrap("left")
local depleted = "down"
local fresh = "up"
while true do
local i = 1
repeat
print(i)


    if reactor.getStackInSlot(i)~=nill then
        if reactor.getStackInSlot(i).name=="reactorUraniumSimple" then
            print("FILLED")
            sleep(1)
        else
            print("DEPLETED")
            reactor.pushItem(depleted,i)
            print("ROD REMOVED")
            reactor.pullItem(fresh,2,1,i)
            print("NEW ROD INSERTED")
            sleep(1)
        end
    end

    if reactor.getStackInSlot(i)==nill then
        print("EMPTY SLOT")
        reactor.pullItem(fresh,2,1,i)
        print("NEW ROD INSERTED")
    sleep(1)
    end
i = i + 2
until i == 55
end