Do other people find these information sheets useful? I am debating about whether to keep posting them.
My fascination with the events unfolding at Fukushima is slowly giving way to the fact that I still have a day job that deals with other topics.
Update to Information Sheet Regarding the Tohoku Earthquake
The Federation of Electric Power Companies of Japan (FEPC) Washington DC Office
As of 3:00PM (EST), April 7, 2011
- Radiation Levels
o The concentration of radioactive nuclides from the seawater sampled at the screen device (installed to remove waste before the intake of seawater) of Unit 2 and sampled near the seawater discharge point (south side) of Fukushima Daiichi Nuclear Station were as follows:
Nuclides (half-life)
Concentration (Unit : Bq/cm3) Ratio Sampled at the screen of Unit 2 at 7:40AM on April 6 (a) Sampled at south side discharge point at 2:05PM on April 6 (b) Maximum Permissible Water Concentration (c) a / c b / c I-131 (8 days)
5.6 x 103 3.7 x 100 4.0 x 10-2 140,000 93 Cs-134 (2 years)
3.1 x 103 2.4 x 100 6.0 x 10-2 52,000 40 Cs-137 (30 years)
3.2 x 103 2.5 x 100 9.0 x 10-2 36,000 28
o At 6:00PM (JST) on April 7, radiation level at main gate (approximately 3,281 feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power Station: 99 micro Sv/hour.
o At 6:00PM on April 7, radiation level at west gate (approximately 3,609 feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power Station: 56.8 micro Sv/hour.
o Measurement results of environmental radioactivity level around Fukushima Nuclear Power Station announced at 7:00PM on April 7 are shown in the attached PDF file. English version is available at: http://www.mext.go.jp/english/radioactivity_level/detail/1304082.htm
o For comparison, a human receives 2,400 micro Sv per year from natural radiation in the form of sunlight, radon, and other sources. One chest CT scan generates 6,900 micro Sv per scan.
- Plant Parameters
Unit 1 Unit 2 Unit 3 Unit 4 Unit 5 Unit 6 pressure inside the reactor core (gauge pressure, MPa) 0.375 -0.009 0.000 – 0.002 0.008 4/7 12:00PM
4/7 12:00PM
4/7 12:00PM
– 4/7 12:00PM
4/7 12:00PM
pressure inside the primary containment vessel (absolute pressure, MPaabs) 0.165 0.100 0.1059 – – – 4/7 12:00PM
4/7 12:00PM
4/7 12:00PM
– – – water level inside the reactor core (meter) *1 -1.65 -1.5 -1.9 – +1.801 +1.816 4/7 12:00PM
4/7 12:00PM
4/7 12:00PM
– 4/7 12:00PM
4/7 12:00PM
temperature of the reactor vessel measured at the water supply nozzle (degrees Fahrenheit) 434.8 290.5 190.9 *2
– – – 4/7 12:00PM
4/7 12:00PM
4/7 12:00PM
– – – temperature of the spent fuel pool (degrees Fahrenheit) – 123.8 – – 96.8 69.8 – 4/7 12:00PM
– – 4/7 12:00PM
4/7 12:00PM
the temperature directly above the spent fuel pool by thermography measurement (degrees Fahrenheit) 75.2 – 140.0 134.6 – – 4/6 7:30AM
– 4/6 7:30AM
4/6 7:30AM
– – temperature directly above the primary containment vessel (degrees Fahrenheit) 84.2 – 89.6 – – – 4/6 7:30
– 4/6 7:30
– – – temperature directly above the second containment building (degrees Fahrenheit) – 89.6 – – – – – 4/6 7:30
– – – – Amount of water in total shot/injected to the spent fuel storage pool (tons) 90 299 – 314 5,048 1,493 – – as of 4/7 7:00PM
as of 4/7 7:00PM
as of 4/7 7:00PM
as of 4/7 7:00PM
– – *1: Minus figure means that water level is below the top of the fuel rods.
*2: This figure is under investigation.
- Fukushima Daiichi Unit 1 reactor
o At 1:31AM on April 7, TEPCO began the injection of nitrogen gas into the primary containment vessel to prevent an explosion by accumulated hydrogen gas.
o As of 3:30PM on April 7, the injection of freshwater into the reactor core continues.
- Fukushima Daiichi Unit 2 reactor
o At 1:29PM on April 7, TEPCO began to inject freshwater into the spent fuel pool, until 2:34PM (approximately 36 tons in total).
o As of 3:30PM on April 7, the injection of freshwater into the reactor core continues.
- Fukushima Daiichi Unit 3 reactor
o At 6:53AM on April 7, TEPCO began to shoot water aimed at the spent fuel pool, until 8:53AM, with a specialized vehicle normally used for pumping concrete (approximately 70 tons in total).
o As of 3:30PM on April 7, the injection of freshwater into the reactor core continues.
- Fukushima Daiichi Unit 4 reactor
o At 6:23PM on April 7, injection of freshwater into the spent fuel pool commenced.
- Fukushima Daiichi Common Spent Fuel Pool
o At 7:45AM on April 7, the temperature of the spent fuel pool: 82.4 degrees Fahrenheit.
- Others
Our official sources are:
- Office of The Prime Minister of Japan
- Nuclear and Industrial Safety Agency (NISA)
- Tokyo Electric Power Company (TEPCO) Press Releases
- Ministry of Education, Culture, Sports, Science and Technology (MEXT)