– Tepco Plans New System to Cool Reactors (Wall Street Journal, May 22, 2011):
TOKYO—Tokyo Electric Power Co. Inc. said Sunday it aims to establish a water-circulation system to ensure continuous cooling of the spent-fuel pools at its stricken Fukushima Daiichi reactors by the end of July.
The troubled utility, known as Tepco, said it plans to build a cooling system with water-circulation pumps and heat-exchange equipment by the end of May at the reactor No. 2 spent-fuel pool, by June at the reactors No. 1 and No. 3 pools, and it plans to have an even more advanced cooling system for the No. 4 reactor pool by July, Tepco official Junichi Matsumoto told a news conference in Tokyo on Sunday.
The reactor No. 4 spent-fuel pool generates more heat than the others, he said, because the rods that have remaining active life are in it.
The new cooling systems would continuously remove radioactive decay heat, lower the amount of water vapor from the spent fuel pools and ensure fuel rods are kept under water, the company said. The establishment of a stable cooling function at the spent fuel pools is an integral part of the company’s ultimate goal of bringing the stricken power plant under control.
Mr. Matsumoto said vapor is still seen sometimes from the spent fuel pools at reactors No. 2, 3 and 4, depending on the weather and wind direction of the day.