Highly radioactive water found on floor of No. 4 reactor in Fukushima nuclear plant

Highly radioactive water found on floor of No. 4 reactor in Fukushima nuclear plant

Tokyo Electric Power Co. discovered possibly highly radioactive water on the first floor of the No. 4 reactor turbine building at its disaster-crippled Fukushima No. 1 nuclear power plant on Tuesday morning. The company believes the water leaked from a pipe that is transferring highly radioactive water from the basement of the No. 3 reactor's turbine building.

A TEPCO worker found the water on the floor of a power control room in the No. 4 reactor turbine building at 11:15 a.m. The company confirmed that the leak had stopped by about 1 p.m. after the radioactive water transfer was suspended at 12:20 p.m. According to TEPCO, a puddle of water about one centimeter deep had collected on the floor of the 350-square-meter power control room. There was no water leak outside the room, the company added.

The water is estimated to contain tens of thousands of becquerels of radioactive cesium per cubic centimeter, according to the firm. (EDIS).

Meanwhile, EneNews brings us quote from the Japan Times Online: according to a recently published study about 30 percent of the Tokyo Electric Power Co. workers at the Fukushima No. 1 nuclear plant were suffering from the disorder called posttraumatic stress response when a survey was conducted in May and June 2011.

The doctors warn that the discrimination and lack of appreciation are harming the workers’ productivity. noted that many confessed they have almost zero work motivation.

“Such low motivation could result in slowing down the restoration process, which will take decades, and possibly trigger accidents,” he said.

Even though the experts said more help is needed, it’s hard to find local help because hospitals in nearby areas have been suffering from a shortage of doctors. (EneNews)

Timeline of the Fukushima Daiichi nuclear disaster

Monday, March 7, 2011 - Warning from TEPCO

Tokyo Electric Power Company (TEPCO) submits a report to Japan's nuclear safety agency which predicts the possibility of a tsunami up to 10.2 metres high at the Fukushima Daiichi nuclear plant in the event of an earthquake similar to the magnitude 7.2 earthquake with accompanying tsunami that devastated the area in 1896. TEPCO actually made this prediction in 2008 but delayed in submitting the report because they "did not feel the need to take prompt action on the estimates".

Friday, March 11, 2011 - Magnitude 9.0 earthquake

  • 14:46: A 9.0 magnitude earthquake strikes off the coast of Honshu Island at a depth of about 24 kilometres (15 mi). The Fukushima I power plant's nuclear reactors 1, 2, and 3 are automatically shut down by the tremor. Nuclear reactors 4, 5, and 6 were undergoing routine maintenance and were not operating, (reactor 4 was defueled in November 2010). The tremor has the additional effect of causing the power plant to be cut off from the Japanese electricity grid, however, backup diesel generators kick in to continue cooling. Tokyo Electric Power Company (TEPCO), the plant's operator, finds that units 1 and 2 are not operating correctly and notifies the proper officials.
  • 14:52: Reactor 1's emergency cooling system, which is capable of running without external power, turns on automatically.
  • 15:03: Reactor 1's emergency cooling system is manually shut down.
  • 15:27: The first tsunami strikes the plant.
  • 15:30: The emergency condenser designed to cool the steam inside the pressure vessel of the No. 1 reactor fails.
  • 15:46 (approximate): A 14-metre (46 ft) tsunami, unleashed by the earthquake, overtops the seawall designed to protect the plant from a tsunami of 5.7 metres (19 ft), inundating the Fukushima facility and disabling the backup diesel generators – all but one of which were housed underground – and washing away their fuel tanks. With the loss of all electrical power supply, the low-pressure core spray, the residual heat removal and low-pressure coolant injection system main pumps, and the automatic depressurization systems all failed (most of the emergency core cooling system). Only the steam-powered pump systems (isolation condenser in reactor 1, high-pressure coolant injection and reactor core isolation cooling system in reactors 2 and 3) remained available. Later, as the temperature rose, a system started that used steam-powered pumps and battery-powered valves.
According to a report in the New York Times, "... at the start of the crisis Friday, immediately after the shattering earthquake, Fukushima plant officials focused their attention on a damaged storage pool for spent nuclear fuel at the No. 2 reactor at Daiichi, said a nuclear executive who requested anonymity ... The damage prompted the plant’s management to divert much of the attention and pumping capacity to that pool, the executive added. The shutdown of the other reactors then proceeded badly, and problems began to cascade."
  • 16:00: The Nuclear and Industrial Safety Agency of Japan (NISA) initiates an emergency headquarters in an attempt to gather information on the 55 nuclear reactors in Japan. There is no report that radiation was detected outside power-plant borders.
  • 18:00: The falling water level in reactor 1 reaches the top of the fuel, and the core temperature starts climbing.
  • 18:18: Reactor 1's emergency cooling system is once again back on.
  • 19:03: Prime Minister Naoto Kan declares a nuclear emergency status announced by Yukio Edano, Chief Cabinet officer in Japan. Japanese government officials try to comfort the people of Japan by telling them that the proper procedures are being undertaken. They also announce that no radioactive leaks have been detected.
  • 19:30: The fuel in reactor 1 becomes fully exposed above the water surface, and fuel damage in the central core begins soon after.
  • 21:00: An evacuation order is issued by the government to persons within a radius of 3 kilometres (1.9 mi) from the Fukushima I station. Those within a radius of 10 kilometres (6.2 mi) are told that they can remain in their homes, and carry on with regular activities, until told otherwise. TEPCO announces that the pressure inside reactor unit 1 of Fukushima I is more than twice normal levels. (Read the rest of timeline here)
Tags: fukushima