Fukushima Daini Nuclear Power Plant
F1
Active reactors ( gross ):
The nuclear power plant, Fukushima Daini and Fukushima II [ ɸɯkɯɕima ] (Japanese福岛 第二 原子 力 発 电 所Fukushima Dai -ni genshiryoku hatsudensho, nuclear power plant, Fukushima No. 2 ') is a nuclear power plant in Japan. It is located in the municipalities of Naraha and Tomioka in the Futaba district in Fukushima prefecture, about 200 kilometers from Tokyo located on the sea. The name is explained by the fact that the plant nearby - about 12 kilometers south - the older nuclear power plant Fukushima Daiichi (Fukushima I) was built.
Technology
The nuclear power plant consists of four boiling water reactors of the fifth generation of a designed by General Electric line of boiling water reactors ( BWR / 5: Boiling Water Reactor). Reactors 1 and 3 come from Toshiba, 2 and 4 by Hitachi. The reactor cores are in safety containers ( containment ), which were also designed by General Electric. It is the containment of the second generation (Mark II).
The complex is located directly on the sea and has its own port. There, cooling water is pumped and radioactive waste shipped. Overall, the plant covers an area of 1.5 km ².
Incidents
At the turn of 1999/2000 was at 8:58 clock in the power plant, the display for the control rods. A clock of the display terminal showed the date " 6 February 2036 " to. After the clock was made , everything went back to normal.
In August 2002, it turned out that 16 years falsified reports of the operator TEPCO and inspections had been deported for reasons of cost. All TEPCO nuclear power plants were subsequently shut down in the coming months. At the Fukushima II, all reactors were shut down during the period from 14 April to 31 August 2003. The last block 4 went on 4 November 2004 again.
Earthquake in Japan 2011
On 11 March 2011 ( 9 magnitude) was during the Tōhoku earthquake, initially made at 14:48 clock time on all four units of the power plant, which were at that time all in the power mode of the automatic reactor control process meet a reactor scram and the insulation condition the reactor containment vessel made . Thus, the loss of the main heat sink was connected planned due to the closed feed water and steam valves. The decay heat removal was done in serving as a replacement heat sink filled with water condensation chambers. Because of the failure of the coolant pumps at Units 1, 2 and 4 here Zusatzwassereinspeisesysteme were used as auxiliary feed pumps.
The triggered by the earthquake, tsunami hit with a height of 6.5 to 7 meters in Fukushima Daini and flooded parts of the power plant site, but did no damage to the reactor blocks.
In blocks 1, 2 and 4 reached on the following day at 5:22, 5:32 or 6:07 clock local time, the temperature in the condensation chambers 100 ° C, and the function of the pressure reduction systems was lost. Therefore, in each case an incident was declared at these time points for these three blocks. To respond to a dangerous rise in pressure in the reactor containment vessels, was prepared a filtered venting of low radioactive Luft-/Wasserdampfgemisch on the exhaust stacks during the day at all four blocks. However, such measures were not necessary. Block 3 had left at 12:15 clock cold ( temperature in the reactor <100 ° C), further cooling measures were in the other blocks still required. The operator TEPCO said on the evening of March 12, the state of all four reactors for stable. At block 1 full backup cooling system on March 14 at 1:24 clock, block 2 was restored at 7:13 clock. The supply of the plant with electric power was ensured throughout. There were several aftershocks. There were several false instrument displays.
During the event, apparently as a direct result of the earthquake, a worker died on the spot when a crane accident, four other workers were injured.
The danger from the temporary loss of pressure reduction systems led to the declaration of a nuclear emergency by the Japanese government, which was immediately before the first time for the more affected nearby nuclear power plant Fukushima Daiichi in Japan's history. First, for Fukushima II evacuation zone of three, arranged later of ten kilometers radius. The evacuation area was, however, almost entirely within the larger evacuation area for Fukushima I. In total, approximately 185,000 persons were evacuated. 230,000 iodine tablets were held to issue on the spot. The temperature of all reactors was reduced on March 15 to below 100 ° C; a condition of the " cold shutdown " or " cold shutdown " is called. The incidents in blocks 1, 2 and 4 were classified by the Japan Atomic Energy Agency on March 12th and 18th 2011 as INES level 3 (" Serious Incident ").
Data of the reactor units
The nuclear power plant in Fukushima II has a total of four blocks: