No Problems at Fukushima From Weekend Quake
July 12, 2011
• An earthquake of magnitude 7.3 struck northeast Japan Sunday morning, prompting tsunami warnings for the coast, including Fukushima prefecture. Tokyo Electric Power Co. ordered workers at the Fukushima Daiichi plant to move to higher ground and suspended the transfer of low-level contaminated water from the plant to a large steel storage barge. However, no problems at the plant were reported after only a small tsunami wave reached the coast. Cooling water injections into reactors 1, 2 and 3 and nitrogen injections into reactors 1 and 2 continued as normal.
• TEPCO suspended operation of its water decontamination system for 12 hours Sunday to repair a leak in the system. The continued operation of the system is crucial to establish a circulatory cooling system for the reactors and to decontaminate and reduce the water accumulating in the reactor building basements. TEPCO has set a July 17 deadline to establish stable cooling for the reactors. As of July 10, the system has treated more than 18,000 metric tons of contaminated water.
• TEPCO has confirmed that an entry point is available to allow nitrogen injection into reactor 3’s pressure containment vessel. The injection of the inert gas will help prevent the potential for a hydrogen explosion. TEPCO reported to the Nuclear and Industrial Safety Agency July 11 on its preparations for the injection, which is to be started “as early as possible.”
• TEPCO is preparing to restart the fuel pool circulating system for reactor 4, after checking that a kink in the reactor heat removal system piping will not block the flow of water. The system is expected to be in service by the end of July. The company sampled the water in reactor 3’s fuel pool and concluded that boric acid injections have helped to prevent corrosion of the aluminum fuel racks. The issue became a concern when concrete debris in the pool caused the water to become more alkaline.
• A long-term roadmap drafted by Japan’s Nuclear Safety Commission and TEPCO calls for the removal of melted fuel from the reactors to begin in 2021, provided the technology required for the task has been developed. Damage to the reactor containment vessels will have to be repaired before the fuel can be removed. Dismantling the reactor buildings after the fuel has been removed will likely take several decades.
• TEPCO officials released the results of a detailed simulation of the tsunami that struck the Fukushima Daiichi and Daini plants on March 11. The analysis showed that the wave reached a height of 13 meters (42.7 feet) at the Daiichi plant and 9 meters (29.5 feet) at the Daini plant.
• At a press conference Monday clarifying the government’s position on restarting Japanese nuclear reactors, Chief Cabinet Secretary Yukio Edano stressed that nuclear safety should be given priority over the issue of whether there will be enough electricity to meet demand. Last week Prime Minister Naoto Kan and Minister for Nuclear Crisis Management Goshi Hosono agreed said that “stress tests” assessing the plants’ safety response to severe accidents should be one of the requirements for restarting the reactors, along with routine safety checks. Edano said a first stage would check plants awaiting restart after scheduled maintenance, and the second phase would be for all plants, including those currently operating.
• The Japanese government is requesting parliamentary approval of a second supplementary budget of two trillion yen ($24.5 billion) for nuclear damage compensation, health checks and radiation monitoring. A previous supplementary budget was used for accident recovery and debris removal work.
• Fukushima prefecture officials are inspecting a cattle farm in Minami-Souma city after elevated levels of radioactive cesium were found in 11 cows shipped from the farm to a Tokyo meat processing firm.
• A Reuters article reported Saturday that Japanese Prime Minister Naoto Kan said it will take decades to clean up and decommission the crippled Fukushima nuclear plant.
• CNN World reported on the Sunday earthquake that prompted tsunami advisories and evacuations of workers at Fukushima Daiichi that were later canceled.
• The NRC task force reviewing agency processes and regulations in light of the accident at Fukushima will brief the commissioners on its report at a public meeting July 19. The report is to be released to Senate and House committees July 12. NRC Chairman Gregory Jaczko will speak at the National Press Club in Washington, D.C., on July 18.