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TEPCO reports 50 problems at N-plant
The Yomiuri Shimbun (Jul. 18, 2007)

     Inspectors have so far discovered 50 problems and instances of damage, including the shifting of an exhaust duct connecting a reactor building and a main exhaust pipe, at the seven reactors of the Kashiwazaki-Kariwa nuclear power plant in Niigata Prefecture after the plant was hit by a major earthquake, Tokyo Electric Power Co. announced Tuesday.
     Radioactive substances such as iodine have been detected coming from the main exhaust pipe at the plant's No. 7 reactor. Although the amount of substances emitted into the atmosphere was extremely small, it is possible some equipment was seriously damaged in Monday's quake. TEPCO said it was investigating exactly how the damage occurred.
     After the earthquake, TEPCO analyzed samples taken from the exhaust sampling device of the main exhaust pipes at the seven reactors. It said there were no radioactive substances detected from the Nos. 1-6 reactors. But iodine, chromium and cobalt--all radioactive substances--were detected from the No. 7 reactor. The amounts were believed to be about one-thousandth of the upper limit of the emission based on safety regulations. The company said such substances are usually contained in the reactor's cooling water.
     About 100 drums containing low-level nuclear waste fell over at a warehouse to store solid waste, and the lids on several drums came off. After inspecting the floor of the warehouse, TEPCO detected an extremely small amount of radiation. It said a total of 22,000 drums are stored at the warehouse so there is a possibility that more drums may have tipped over.


TEPCO admits flaws in safety measures
The Yomiuri Shimbun (Jul. 18, 2007)

     Tokyo Electric Power Co.'s disaster prevention measures did not function successfully when Monday's Niigata Prefecture Chuetsu Offshore Earthquake hit its Kashiwazaki-Kariwa nuclear power plant in Niigata Prefecture, the company said Tuesday.
     The power company added that only four workers were available to extinguish the fire after it was discovered.
     The government plans an immediate review of the nation's 55 nuclear reactors by means of new seismic integrity standards, Economy, Trade and Industry Minister Akira Amari said during a press conference Tuesday.
     The vibration of the earthquake, which surpassed quake-resistance levels, reached an acceleration of 680 gals at the Kashiwazaki-Kariwa nuclear power plant.
     Prime Minister Shinzo Abe on Monday night ordered Amari to take immediate action against TEPCO as it had failed to swiftly confirm the fire had been extinguished and that radioactive material leaked from the plant. The fire was triggered by a power transformer outside one of the reactors.
     TEPCO also failed to report the fire and leak in time for Monday night's Cabinet meeting. Abe blasted TEPCO, saying its lack of action presented a serious problem, sources said.
     Amari reprimanded TEPCO President Tsunehisa Katsumata at the ministry early Tuesday, and ordered the company to review its procedures for extinguishing any immediately reporting fires.
     Amari also ordered Katsumata to find the cause of the radioactive coolant leak and to report on the reason for the delays. The minister also told him not to restart the Kashiwazaki-Kariwa nuclear power plant until its safety has been confirmed.
     TEPCO said it failed to take swift measures as it could not secure enough staff to deal with all the incidents at once, and therefore it failed to promptly report its situation to the ministry, the company said.
     The transformer fire was found at 10:15 a.m. Monday. However, it was not until 11:33 a.m. that local firefighters, which had been busy assisting quake victims, began fighting the fire.
     "Other facilities also were damaged, and our instructions were confused," the company said, admitting its disaster management measures did not go as planned. "Fire engines and ambulances usually are out on call in the event of disasters. Nuclear power plants need to set up a system for putting out fires on their own," Amari said Tuesday.
     At 12:50 p.m. Monday, TEPCO discovered a water leak in an area not yet under control--the area adjacent to the storage pool for spent fuel from the No. 6 reactor, whose operation had been suspended for regular inspection at the time of the earthquake, it said.
     The company decided to check the area later as the reactor and the pool are separated by a partition dozens of centimeters thick, it said.
     It was not until about six hours later that TEPCO discovered the coolant contained radioactive material. It was not until 8:28 p.m. that the power company reported that coolant had escaped into the sea, according to the company.

suite:
Radioactive materials discharged from main exhaust stack at nuke plant after quake
The Yomiuri Shimbun (Jul. 18, 2007)

     Quake damage at the Kashiwazaki-Kariwa Nuclear Power Plant was more extensive than initially thought, with radioactive materials discharged into the air, barrels of waste overturning and transformers leaking oil, officials said.
     Tokyo Electric Power Co. (TEPCO), operator of the plant, said 50 cases of mechanical glitches and damage were confirmed at the plant's seven reactors after Monday's powerful earthquake rocked Niigata and Nagano prefectures.
     The latest findings came after TEPCO acknowledged that water containing radioactive materials flowed into the Sea of Japan because of the temblor and that an electric transformer caught fire.
     Although TEPCO says the radioactive substances that leaked outside pose no health risks, the damage exposed the vulnerability of nuclear power plants in major earthquakes, experts warn. The Kashiwazaki-Kariwa Nuclear Power Plant was designed to withstand shaking from a quake at a level much lower than what was recorded Monday.
     "We need to review (the situation), including conducting anti-quake reinforcement work," a TEPCO official said.
     The plant's seven reactors have been shut down.
     The quake, with a magnitude of 6.8 and an intensity of upper 6 on the Japanese scale of 7, left at least nine people dead and injured more than 1,000.
     The epicenter of the quake is estimated to be only 9 kilometers from the plant's location.
     The radioactive substances that leaked into the air came through the main exhaust stack used to decontaminate air inside a steam condenser.
     The condenser cools steam generated at the reactor and converts it back into water. The air is decontaminated and discharged through the exhaust stack.
     When TEPCO conducted checks Tuesday, it detected radioactive substances, such as iodine, chrome and cobalt, outside the reactor, the company said.
     The company said an estimated 300 million becquerels of radiation was detected at the plant, a figure about one-thousandth of the legal limit, TEPCO said, adding that there should be no ill effects on people or the environment.
     But the company said it has yet to determine the cause of the leak at the No. 7 reactor exhaust stack. TEPCO said radioactive materials are usually kept inside nuclear reactors.
     The earthquake also caused exhaust ducts at the No. 1, 2, 3, 4 and 5 reactors to shift a little, but TEPCO officials said there was only a small likelihood that air containing radioactive substances had leaked outside the reactor.
     In addition, the shaking caused about 100 metal barrels containing low-level radioactive waste to topple. The lids of some of the barrels came off.
     Radioactive materials measuring 0.5 becquerels per square centimeter were confirmed from part of the floor.
     About 22,000 barrels, containing waste such as screws, piping materials, gloves and incinerated ash, are kept at the plant's two storage buildings.
     Meanwhile, the water containing trace amounts of radioactive materials from a spent fuel pool at the No. 6 reactor continued to leak inside the plant on Tuesday.
     The leak started Monday after the quake rocked the spent fuel pool, causing the water to flow into drainage ditches leading to the Sea of Japan.
     The flow of the radioactive water outside was stopped on Monday, but one drop of radioactive water formed every three seconds Tuesday inside the reactor building.
     The earthquake also caused other spent fuel pools to overflow, flooding the top floors of the reactor buildings.
     In addition, seven electric transformers other than the one that caught fire were found to have suffered minor damage, such as oil leaks and broken bolts.
At least one water-supply pipe for fire-fighting was damaged, resulting in water leaks, TEPCO said.
     "It cannot be denied that a fire might have occurred at several transformers, and the fire control equipment was not functioning properly," the TEPCO official said. (IHT/Asahi: July 18,2007)