Please find the updated information sheet below and attached that summarizes the events from Update-40 at 11:40AM on 5/5.
For your reference, JAIF (Japan Atomic Industrial Forum) has been posting the translation of news reports on their website.
Please direct any questions regarding this document to me, Ishida@denjiren.com or Samuel Lederer, Researcher of FEPC at lederer@denjiren.com.
Update to Information Sheet Regarding the Tohoku Earthquake
The Federation of Electric Power Companies of Japan (FEPC) Washington DC Office
As of 09:00PM (EST), May 6, 2011
All times listed below are Japan Standard Time (JST) unless otherwise noted.
- Radiation Levels
- 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 inside the silt fence at the screen of Unit 2 | Sampled outside the silt fence at the screen of Unit 2 | Sampled at south side discharge point | Maximum Permissible Water Concentration (d) | a / d | b / d | c / d | |
5/5 7:30AM (a) | 5/5 7:20AM (b) | 5/5 2:10PM (c) | |||||
I-131 (8 days) | 9.4 x 100 | 3.9 x 100 | 7.7 x 10-3 | 4.0 x 10-2 | 240 | 98 | 0.19 |
Cs-134 (2 years) | 3.7 x 100 | 3.9 x 100 | 6.3 x 10-2 | 6.0 x 10-2 | 62 | 65 | 1.1 |
Cs-137 (30 years) | 3.7 x 100 | 4.0 x 100 | 7.1 x 10-2 | 9.0 x 10-2 | 41 | 44 | 0.79 |
- At 2:00PM on May 6, radiation level at main gate (approximately 3,281 feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power Station: 46 micro Sv/hour.
- At 2:00PM on May 6, radiation level at west gate (approximately 3,609 feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power Station: 18.7 micro Sv/hour.
- Measurement results of environmental radioactivity level around Fukushima Nuclear Power Station announced at 10:00AM on May 6 are shown in the attached PDF file. English version is available at: http://www.mext.go.jp/
english/incident/1304082.htm - 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) | 0.465 | -0.020 | -0.079 | - | 0.006 | 0.016 |
5/6 11:00AM | 5/6 11:00AM | 5/6 11:00AM | - | 5/6 13:00PM | 5/6 13:00PM | |
pressure inside the primary containment vessel (absolute pressure, MPaabs) | 0.130 | 0.065 | 0.1043 | - | - | - |
5/6 11:00AM | 5/6 11:00AM | 5/6 11:00AM | - | - | - | |
water level inside the reactor core (meter) *1 | -1.65 | -1.5 | -2.1 | - | +1.967 | +2.286 |
5/6 11:00AM | 5/6 11:00AM | 5/6 11:00AM | - | 5/6 13:00PM | 5/6 13:00PM | |
temperature of the reactor vessel measured at the water supply nozzle (degrees Fahrenheit) | 273.4 | 241.5 | 326.3 | - | - | - |
5/6 11:00AM | 5/6 11:00AM | 5/6 11:00AM | - | - | - | |
temperature of the spent fuel pool (degrees Fahrenheit) | - | 158.0 | - | - | 101.7 | 84.2 |
- | 5/6 11:00AM | - | - | 5/6 13:00PM | 5/6 13:00PM | |
Amount of water in total shot/injected to the spent fuel storage pool (tons) | 90 | 697 - 712 | 5,390.5 | 3,306.2 | - | - |
as of 5/5 5:00PM | as of 5/5 5:00PM | as of 5/5 5:00PM | as of 5/5 5:00PM | - | - |
*1: A negative figure indicates that the water level is below the top of the fuel rods.
- Fukushima Daiichi Unit 1 reactor
- At 4:36PM on May 5, TEPCO began operating six air circulators which have been installed at the turbine building in order to reduce the radioactive concentration of the reactor building.
- At 10:01AM on May 6, TEPCO began to increase the injection volume of freshwater into the reactor core from 6m3 /hour to 8m3 /hour in order to flood the primary containment vessel to the level at which the fuel in the reactor can be fully submerged for cold shutdown of the reactor.
- As of 3:00PM on May 6, injection of nitrogen gas into the primary containment vessel to prevent an explosion by accumulated hydrogen gas continues.
- As of 3:00PM on May 6, the injection of freshwater into the reactor core continues.
- Fukushima Daiichi Unit 2 reactor
- At 9:36AM on May 6, TEPCO began to inject freshwater into the spent fuel pool, until 11:16AM (approximately 58 tons in total).
- As of 3:00PM on May 6, the injection of freshwater into the reactor core continues.
- Fukushima Daiichi Unit 3 reactor
- As of 3:00PM on May 6, the injection of freshwater into the reactor core continues.
- Fukushima Daiichi Unit 4 reactor
- At 12:38PM on May 6, TEPCO began to shoot freshwater aimed at the spent fuel pool, with a specialized vehicle normally used for pumping concrete.
- Fukushima Daiichi Unit 6 reactor
- At 2:00PM on May 6, transferring of the accumulated water at the turbine building to the temporary tank commenced.
- Fukushima Daiichi Common Spent Fuel Pool
- As of 6:30AM on May 6, the temperature of the spent fuel pool: 77.0 degrees Fahrenheit.
- Others
- On May 6, TEPCO dispersed dust suppressant around the reactor building of Unit 1 in order to prevent diffusion of radioactive materials.
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)
- Ministry of Defense (MOD)
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Taro Ishida
The Federation of Electric Power Companies of Japan
1901 L Street, NW Suite 600
Washington, DC 20036
1901 L Street, NW Suite 600
Washington, DC 20036
Mobile (202) 253-2579
Phone (202) 530-0769 (Direct)
Phone (202) 466-6781
Fax (202) 466-6758
Phone (202) 466-6781
Fax (202) 466-6758
email: ishida@denjiren.com
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