Tokyo Electric Power Company says the cooling of spent nuclear fuel pools remains disrupted on Tuesday at the damaged Fukushima Daiichi nuclear power plant.A momentary power blackout caused a malfunction in the cooling system on Monday. Spent fuel pools of the No. 1, 3 and 4 reactor units and another pool for shared use were affected, according to Japan’s (NHK WORLD).TEPCO officials said they found that three high voltage power distribution systems, which receive power from outside the plant, stopped functioning. Two of them were repaired but a problem with the third unit has yet to be identified. As a result the cooling system could not be restored.The water temperature of each fuel pool remained steady at between 16 and 30 degrees Celsius on Tuesday.TEPCO officials say it will take about four days for the pool at the No.4 unit — the hottest one — to exceed the safety limit of 65 degrees Celsius.They are planning to replace the damaged electric switchboard or reconnect the cooling system to other switchboards to resume cooling of the pools as soon as possible.Officials say the utility’s in-house rules mandate water injection using fire engines if the fuel pools’ cooling system does not work properly for two days or more.