Purpose and Introduction: This diary has been set up as a repository for easily accessible temperature, pressure etc readings; amount of fuel at the plant; radiation levels in air, water and food; reported radiation exposure; changes in allowable limits of radiation exposure; links to images of the damaged power plant and other information over time at the Daiichi nuclear power plant. For example, do you want to know what the temperature readings were for reactor #3's spent fuel pool on Mar 19th? If one was made available, it should be here. If one was not made available, that is also recorded here. In order to conserve space, some information is simply linked to. In addition there is some basic reference material linked to at the end.
This database was designed to be used in conjunction with the Kos Japan Nuclear Incident Group, and is considered, for purposes of editing, to be the entire group's diary. Any editor or admin of that group is welcome to add updates, new information or entire sections of interest. If you have other relevant data, please feel free to store it here, either in the text (please try to adhere to the categorical organization) or the comments, for all to be able to access and reference. Just be sure to include a link.
This diary is meant to be added to and updated as time goes on.
Much thanks to Siri for documenting the pressure and temperature readings!
Pressure and Temperature Readings at the Reactors and SFPs
Fukushima - Daiichi
Updated with readings as of: 3/25/2011
Please note: The water levels are measured from the top of the assemblies down to where the water is. These assemblies are exposed.
a "-" sign will be in front of the number as long as they are reporting that water is below the assemblies.
Pressure readings are MPa, Temperature reading are Celcius, Water level reading are in milimeters (mm). Readings were obtained from GRS (1) and (2)
Reactor 1 |
Reactor Pressure Gauge 1 |
Reactor Pressure Gauge 2 |
Reactor Water Level |
Reactor water level 2 |
Reactor Containment Pressure |
Reactor - Condensation Chamber Pressure |
17-Mar |
0.173 |
0.144 |
-1800 |
xxxxx |
n/a |
n/a |
18-Mar |
0.265 |
0.243 |
-1700 |
xxxxx |
n/a |
n/a |
19-Mar |
0.306 |
0.256 |
-1750 |
xxxxx |
n/a |
n/a |
20-Mar |
0.304 |
0.263 |
-1750 |
xxxxx |
0.18 |
0.17 |
21-Mar |
0.297 |
0.265 |
-1750 |
xxxxx |
0.16 |
0.16 |
22-Mar |
0.328 |
0.306 |
-1800 |
-1750 |
0.175 |
0.155 |
23-Mar |
0.481 |
0.495 |
-1750 |
-1700 |
0.36 |
0.33 |
24-Mar |
0.511 |
0.488 |
-1700 |
-1700 |
0.37 |
0.385 |
25-Mar |
0.453 |
0.453 |
-1650 |
-1600 |
0.275 |
0.275 |
____________
Reactor 1 |
Reactor Water Temp. C |
Spent Fuel Pool Water Temp. C |
Temp on RPV Feedwater nozzle/plenum at bottom |
17-Mar |
unknown |
unknown |
unknown |
18-Mar |
unknown |
unknown |
unknown |
19-Mar |
unknown |
unknown |
unknown |
20-Mar |
unknown |
unknown |
unknown |
21-Mar |
unknown |
unknown |
unknown |
22-Mar |
unknown |
unknown |
unknown |
23-Mar |
unknown |
unknown |
305/306 |
24-Mar |
unknown |
unknown |
243/229 |
25-Mar |
unknown |
unknown |
196.9/148.5 |
|
|
|
|
Reactor 2 |
Reactor Pressure Gauge 1 |
Reactor Pressure Gauge 2 |
Reactor Water Level |
Reactor water level 2 |
Reactor Containment Pressure |
Reactor - Condensation Chamber Pressure |
17-Mar |
0.029 |
0.047 |
-1800 |
xxxxx |
n/a |
n/a |
18-Mar |
0.085 |
0.069 |
-1400 |
xxxxx |
n/a |
n/a |
19-Mar |
0.096 |
0.083 |
-1400 |
xxxxx |
n/a |
n/a |
20-Mar |
0.087 |
0.072 |
-1300 |
xxxxx |
n/a |
under measuring range |
21-Mar |
0.081 |
0.081 |
-1350 |
xxxxx |
0.12 |
under measuring range |
22-Mar |
0.08 |
0.083 |
-1350 |
xxxxx |
0.11 |
under measuring range |
23-Mar |
0.065 |
0.065 |
-1250 |
xxxxx |
0.11 |
under measuring range |
24-Mar |
0.076 |
0.076 |
-1000 |
xxxxx |
0.105 |
under measuring range |
25-Mar |
0.085 |
0.083 |
-1400 |
xxxxx |
0.12 |
under measuring range |
________________
Reactor 2 |
Reactor Water Temp. C |
Spent Fuel Pool Water Temp. C |
Temp on RPV Feedwater nozzle/plenum at bottom |
17-Mar |
unknown |
unknown |
unknown |
18-Mar |
unknown |
unknown |
unknown |
19-Mar |
unknown |
unknown |
unknown |
20-Mar |
unknown |
unknown |
unknown |
21-Mar |
unknown |
49.0 |
unknown |
22-Mar |
unknown |
53.0 |
unknown |
23-Mar |
unknown |
52 |
101/102 |
24-Mar |
unknown |
52 |
102/109 |
25-Mar |
unknown |
52 |
107/104 |
Reactor 3 |
Reactor Pressure Gauge 1 |
Reactor Pressure Gauge 2 |
Reactor Pressure Gauge c |
Reactor Water Level |
Reactor water level 2 |
Reactor Containment Pressure |
Reactor - Condensation Chamber Pressure |
17-Mar |
0.014 |
0.023 |
unknown |
-1950 |
unknown |
n/a |
n/a |
18-Mar |
0.096 |
0.115 |
unknown |
-2000 |
unknown |
n/a |
n/a |
19-Mar |
0.146 |
0.106 |
unknown |
-1200 |
unknown |
n/a |
n/a |
20-Mar |
0.281 |
0.317 |
unknown |
-1950 |
unknown |
0.34 |
under measuring range |
21-Mar |
No reading |
0.144 |
0.18 |
-1600 |
unknown |
0.12 |
under measuring range |
22-Mar |
No reading |
No reading |
0.137 |
-1575 |
-2350 |
0.1 |
under measuring range |
23-Mar |
No reading |
0.003 |
0.135 |
-1800 |
-2300 |
0.1 |
under measuring range |
24-Mar |
No reading |
0.004 |
0.142 |
-1800 |
-2300 |
under range |
at full scale |
25-Mar |
0.137 |
0.002 |
n/a |
-1900 |
-2300 |
0.1075 |
0.2 |
Please note: On 3/21 a reading was given for Gauge C of .018. This is the first mention of a "gauge c" and there is no reading for gauge a
_________________
Reactor 3 |
Reactor - Condensation Chamber Pressure |
Reactor Water Temp. C |
Spent Fuel Pool Water Temp. C |
Temp on RPV Feedwater nozzle/plenum at bottom |
17-Mar |
n/a |
unknown |
unknown |
|
18-Mar |
n/a |
unknown |
unknown |
|
19-Mar |
n/a |
unknown |
unknown |
|
20-Mar |
under measuring range |
unknown |
unknown |
|
21-Mar |
under measuring range |
unknown |
unknown |
|
22-Mar |
under measuring range |
unknown |
unknown |
|
23-Mar |
under measuring range |
unknown |
unknown |
n/a |
24-Mar |
at full scale |
unknown |
unknown |
80.7/185.4 |
25-Mar |
0.2 |
unknown |
unknown |
-33.4 (under survey)//111 |
Reactor 4 |
Reactor Water Temp. C |
Spent Fuel Pool Water Temp. C |
16-Mar |
XXXXX |
84.0 |
17-Mar |
XXXXX |
unknown |
18-Mar |
XXXXX |
unknown |
19-Mar |
XXXXX |
unknown |
20-Mar |
XXXXX |
unknown |
21-Mar |
XXXXX |
unknown |
22-Mar |
XXXXX |
unknown |
23-Mar |
XXXXX |
unknown |
24-Mar |
XXXXX |
100.0 |
25-Mar |
XXXXX |
indication failure |
- There are no fuel rods in the core of reactor four. All fuel rods are in the spent fuel pool. No readings published since 3/16
- There are no pressure readings for reactor 4.
Reactor 5 |
Reactor Water Temp. C |
Spent Fuel Pool Water Temp. C |
14-Mar |
XXXXX |
59.7 |
15-Mar |
XXXXX |
60.4 |
16-Mar |
XXXXX |
62.7 |
17-Mar |
XXXXX |
64.2 |
18-Mar |
XXXXX |
65.5 |
19-Mar |
XXXXX |
68.8 |
20-Mar |
XXXXX |
48.1 |
21-Mar |
XXXXX |
42.2 |
22-Mar |
XXXXX |
37.5 |
23-Mar |
XXXXX |
41.1 |
24-Mar |
XXXXX |
45.1 |
25-Mar |
XXXXX |
37.9 |
- There are no pressure readings for reactor 5.
- Spent Fuel Pool temps had been decreasing in #5. Power supply to Unit 5 was switched from the Emergency Diesel Generator to external power supply. (11:36 March 21st) The pumps for Residual Heat Removal (RHR) was automatically stopped when the power supply was switched from the temporary to the permanent. (17:24 March 23rd). RHR Pump is now working.
Reactor 6 |
Reactor Water Temp. C |
Spent Fuel Pool Water Temp. C |
14-Mar |
XXXXX |
58.0 |
15-Mar |
XXXXX |
58.5 |
16-Mar |
XXXXX |
60.0 |
17-Mar |
XXXXX |
62.5 |
18-Mar |
XXXXX |
62.0 |
19-Mar |
XXXXX |
66.5 |
20-Mar |
XXXXX |
67.0 |
21-Mar |
XXXXX |
35.0 |
22-Mar |
XXXXX |
34.1 |
23-Mar |
XXXXX |
19.0 |
24-Mar |
XXXXX |
23.5 |
25-Mar |
XXXXX |
22.0 |
- There are no pressure readings for reactor 6.
How Much Fuel Is At This Plant?
Update on fuel in the spent fuel pools at each reactor, when the fuel was changed, and how much spent fuel there is per reactor unit (fuel is reported in irradiated vs. unirradiated assemblied): Based on IAEA reports
When was it first known there was a problem?
From NIRS,
On Saturday night, Citizens Nuclear Information Center in Tokyo held a press conference with Mitsuhiko Tanaka, a nuclear engineer who helped design the Unit 4 reactor pressure vessel. He conducted an analysis of the events at Unit 1 (the first reactor to experience an explosion, barely 24 hours after the earthquake) and concludes that Unit 1 suffered a Loss-of-Coolant Accident within hours of the earthquake. Indeed, it is likely the earthquake caused a key cooling pipe to rupture. Tanaka noted that an attempt was made to initiate the emergency core cooling system within two hours of the earthquake, which failed because of lack of power.
The implication of this analysis is that TEPCO knew within hours—probably less than two hours—of the earthquake that a nuclear meltdown was likely, and yet did not the public nor seek an immediate evacuation of the area. It also indicates that, contrary to nuclear industry statements, that the reactors did not even withstand the earthquake itself. If true, and Tanaka acknowledged some key data is still incomplete, this will likely have serious repercussions on TEPCO as well as government nuclear safety authorities if they were aware of the situation.
Japan Times corroborates this time frame, and adds:
By the evening of March 11, hours after the massive quake hit northern Japan and the ensuing tsunami wiped out towns on the Pacific coast of Tohoku, the Nuclear and Industrial Safety Agency had drawn up the worst-case scenario for the troubled No. 2 reactor: Its failed cooling system could cause the fuel rods in the core to start burning up and release radioactive material outside it.
The government's nuclear watchdog conveyed its assessment of the reactor's state to Kan's team at 10:30 p.m., the sources said. By the early hours of March 12, high levels of radioactive iodine had been detected at the plant, which is operated by Tokyo Electric Power Co.
Around the same time, pressure in the No. 1 reactor had begun to rise. That was the most critical point in the emergency because it was necessary to lower the pressure in the reactors and prevent an explosion, the unnamed sources said. But Kan flew in to view the power plant in the early morning of March 12.
"How could Tepco irradiate the prime minister flying up above by ventilating the reactors?" asked a government official familiar with the development. "His inspection delayed the ventilating steps."
It was not clear whether Tepco emphatically warned Kan to stay away. Tepco started the process to ventilate the reactors at 9:04 a.m. only after the chopper Kan was aboard left the area, the sources said. But workers could not open valves that were necessary to release the air until 2:30 p.m., the sources said. Despite ventilation, a hydrogen explosion occurred at the No. 1 reactor hours later.
A nuclear expert close to the government's nuclear policy speculated that the loss of time at the initial stage probably narrowed the scope of options available to contain the crisis.
(h/t: DRo and Siri)
Radiation in Air, Water and Food
Air
The data released by the NSC on Wednesday brought to light the fact that there are considerable differences in radiation levels between areas, even within 30 kilometers of the troubled nuclear power plant in Fukushima Prefecture.
Significantly high radiation readings were recorded in some areas outside the 30-kilometer zone, according to the commission, as the spread of radioactive substances depends heavily on geography and wind direction.
- TEPCO Mar 24, 2011 report link to pdf, second report here; TEPCO press release with links to other reports can be found here
- Radiation Monitoring in Japan: Crowd-sourced real time radiation monitoring hosted by Pachube community. An excellent source with linked maps in various formats. (h/t: Cosmic Debris)
- Nearly hourly updates in the surrounding Fukushima area: an excel file that is updated with great frequency is linked to in this NIRS article.
Food
Drinking Water
- Allowable limits for infants and adults for I-131:
The central government's limit is 100 becquerels for safe consumption by infants under 1 and 300 becquerels for adults. Japan Times
- An excellent set of graphs of the levels of I-131 and Cs-137 over time by prefecture can be found in English (thank you, Google Translate!) here. These tables run from Mar 21-25, 2011. They were originally published here (Japanese). (h/t: ricklewsive)
Please note: the tables (the Japanese link) may be updated on a regular basis. To see updated tables, click the Japanese link, then copy/paste the tables into Google Translate, Japanese --> English, for updated tables.
- A Japan Times article from Mar 27, 2011 can be found here.
Sea Water
Sea water monitoring is important due to the large fishing grounds near Fukushima.
The Oyashio Current is cold water flowing south past the reactor region; the Kuroshio Current is warm water flowing north past Tokyo. They meet midway around Hokkaido and mix to create a productive sea life and seafood grounds.
Injuries
- Three workers were injured Mar. 24, 2011 while working in the turbine building for reactor #3 (Kyodo News). The suffered severe beta burns on their lower legs and feet while wading through water in the building. A nucleide analysis was done on the water in the "puddle" (TEPCO analysis) This water was severely contaminated. The results are seen below.
Two of these workers have been reported to have been exposed to between 2 and 6 Sieverts from this accident. (NY Times)
TEPCO performed a separate analysis on a similar puddle in the turbine building of unit 1. Results are below (Link to TEPCO/NISA Mar 26, 2011 report):
- The results of the measurement of puddle of water in the basement of the turbine building of Unit 2 of Fukushima Daiichi Nuclear Power Station.(2nd release) (TEPCO):
APPENDIX
March 27, 2011
Result of Contamination Check of Water in the Basement
At the Turbine Building of Each Unit 2 of Fukushima Daiichi Power Station
|
Density of Radioactive Materials (Bq/cm3) |
|
Unit 2 (Error) Obtained at around 8:50 on March 26 Measured at around 18:50 March 26 |
Unit 2 (Reassessment) Obtained at around 8:50 on March 26 Measured at around 18:50 March 26 |
Unit 2 (re-measurement) Obtained at around 8:50 on March 26 Measured at around 12:50 March 27 |
Unit 2 (re-extraction) Obtained at around 20:40 on March 27 Measured at around 22:30 March 27 |
Radioactive
Materials (T1/2) |
Radiation Dose Rate in the Surface of Water >1000mSv/h, |
Radiation Dose Rate in the Surface of Water >1000mSv/h, |
Radiation Dose Rate in the Surface of Water >1000mSv/h, |
Co-56
(approx.77days) |
1.6×105 |
under the limit |
under the limit |
under the limit |
Co-58
(approx.71days) |
under the limit |
under the limit |
under the limit |
under the limit |
Co-60
(approx.5years) |
under the limit |
under the limit |
under the limit |
under the limit |
Mo-99
(approx.66hours) |
under the limit |
under the limit |
under the limit |
under the limit |
Tc-99m
(approx.6hours) |
8.7×104 |
8.7×104 |
4.8×105 |
under the limit |
Ru-106
(approx.370days) |
under the limit |
under the limit |
under the limit |
under the limit |
Ag-108m
(approx.418years) |
2.5×105 |
under the limit |
under the limit |
under the limit |
Te-129
(approx.70mins) |
under the limit |
under the limit |
under the limit |
under the limit |
Te-129m
(approx.34days) |
under the limit |
under the limit |
under the limit |
under the limit |
Te-132
(approx.3days) |
under the limit |
under the limit |
under the limit |
under the limit |
I-131
(approx.8days) |
1.3×107 |
1.3×107 |
1.3×107 |
1.3×107 |
I-132
(approx.2hours) |
under the limit |
under the limit |
under the limit |
under the limit |
I-134
(approx.53mins) |
2.9×109 |
under the limit |
under the limit |
under the limit |
Cs-134
(approx.2years) |
2.3×106 |
2.3×106 |
2.2×106 |
3.1×106 |
Cs-136
(approx.13days) |
2.5×105 |
2.5×105 |
2.5×105 |
3.2×105 |
Cs-137
(approx.30years) |
2.3×106 |
2.3×106 |
2.2×106 |
3.0×106 |
Ba-140
(approx.13days) |
4.9×105 |
4.9×105 |
4.9×105 |
6.8×105 |
La-140
(approx.2days) |
1.9×105 |
1.9×105 |
1.8×105 |
3.4×105 |
Total |
2.9×109 |
1.9×107 |
1.9×107 |
2.0×107 |
- Including the above mentioned three workers, a total of 18 workers have been exposed to radiation exceeding 100 mSv, the original allowable limit (See pages 18-20 of this NISA report).
Radiation Limits
- In response to increases in radiation levels, the allowable limits have been increased in order to allow people to continue working at, or living near the plant.
- General population in the surrounding region: As reported in the 55th Seismic Damage Information report, on Mar 20, the Local Emergency Response Headquarters issued a directive to change the reference value on screening levels
for decontamination of radioactivity as the following to the Prefectural Governor and the heads of cities, towns and villages (Tomioka Town, Hutaba Town, Okuma Town, Namie Town, Kawauchi Village, Naraha Town, Minamisouma City, Tamura City, Kazurao Village, Hirono Town, Iwaki City and Iidate Village).
Old : 40 Bq/cm2 measured by a gamma-ray survey meter or 6,000 cpm
New : 1 μSv/hour (dose rate at 10cm distance) or 100,000cpm equivalent
links
(1) and
(2).
An article on this disturbing adaptation can be found here.
Images (Links)
Infrared images of the reactors: link
"The Fukushima 50": trying to stabilize the plant Photo Essay from Daily Mail UK, Mar 23, 2011.
Video fly-by of each of the reactor buildings shot Mar 25, 2011 by SDF, provided by NHK
Slide show with diagrams of plant and reactors: The following link is to a marvelously well done slide show with diagrams of the plant, its reactor designs, explanations of the explosions, etc. by German nuclear scientist Dr. Matthias Braun who works for Areva h/t to Drama Queen who took the following exception to the presentation:
My only issue is that page 32 shows spent pool 4 drying up in 10 days and the other spent pools drying up in weeks and no one on the DK comment threads can tell me why. Does the author know that the cooling systems are failing? Or that the salt crusting has rendered even an intact cooling system eventually fatally inefficient?
Basic Information
What is happening inside the reactor: This is a good, simple explanation. h/t: Pluto (The Denki Shimbun)
The Nuclear Accident Scale: This IAEA produced very large pdf (h/t: gchaucer2) gives the INES scale from 1-7 and and defines the different ratings of nuclear disasters. It includes examples of previous disasters and where they fell on the scale.
For example:
7. Chernobyl, 1986 -- effect on people and environment;
6. Kyshtym, Russia, 1957 -- effect on people and environment -- significant release due to exploding radioactive waste tank;
5. Windscale Pile, UK, 1957 -- effect on people and environment --fire in reactor core;
5. Three Mile Island, 1979 -- Radiological Barriers and Control;
4. Toakaimura, Japan 1999 -- effect on people and environment -- fatal exposures to workers after failure at nuke plant.
Units of Measure for Radiation: Whitis has provided useful information on the various units (Bq, Sv, CPM, etc) used to measure radiation (link to whitis' comment).
The significance of certain isotopes in terms of core breach: The presence of certain short lived isotopes can be indicative of radiation coming from the core itself. More official information is needed here, however, this diary by Kossack and physicist rb137 contains a helpful comment thread on this.
Information of the short-lived substance Technetium-99m, which was present in the pool of water in turbine building #3's basement (see the "Injuries" section, above), can be found here.
Information of two-stage radioactive decay can be found here.
Different Iodine Isotopes: There are 37 well characterized isotopes of iodine, each with its own half-life. I-131 with its 8 day half-life is by no means the only isotope there is, nor is it the only one produced by fission. For example, I-129 is a long-lived marker for nuclear fission contamination and was used following Chernobyl. It has a half-life of 15.7 billion years. Read more here at this Wiki page.
Radiation Equivalents: This is a highly useful graphic representation of how much radiation is in say a mammogram vs. a Sv. Have a look at this dose chart.
Radiation Sickness: This wiki page gives a good description of immediate and short term effects of high doses of radiation, as well as a table of what symptoms and diseases are experienced at what radiation exposure levels. Wiki