Fukushima: Texas A&M forecasts, other simulations.

The Texas A&M forecasts are in:

Monday, April 4
• 2011-04-04 12Z - forecast only
• 2011-04-04 06Z - forecast only
• 2011-04-04 00Z - forecast only

I also found some readings from KEK in Tokyo, that are similar but more frequently updated than the SPEED! measurements. They are here and here. As shown earlier, these measurements show several spikes stemming from the releases from the reactors and a larger set of bump starting around March 21st that seem to correlate with the pool cooling events. As soon as the pools are filled, i.e. cooled, the sources terms stops immediately.

At the start of the accidents, there was not much data with regards to the source term at Fukushima, i.e how much elements were escaping from the reactors. Most of the computations performed by different groups were focused on  a worst case scenario of continuous release, which was never supported by any of the SPEED! measurements. The simulations include:

• Special Forecast products for Fukushima produced by NILU-ATMOS (disclaimer: These products are highly uncertain based on limited information for the source terms. Please use with caution and understand that the values are likely to change once we obtain more information on the overall nature of the accident. The products should be considered informational and only indicate 'worst case scenario' releases. From what we've learned recently, it seems releases of this magnitude have not yet occurred. Furthermore, these modeling products are based on global meteorological data, which are too coarse to provide reliable details of the transport of the plume across Japan.)
• Eurad simulations. (Fukushima site) Disclaimer: This simulation is a so called "worst case scenario" with continuous release rate. The value of 0001 Bq / m 3 correspond to appr. one millionth of the concentration at the source. At distances more than appr. 2000 km away from the source, the concentrations are not harmful to health. The simulation starts at fictitious 15.03. 00 UTC and will continue to run in order to Demonstrate the InterContinental. Relaese exact transport When rates are published we will restart the simulation with reliable values.

When given more data from the CTBTO, the german Eurad model was re-run and the dispersion model was compared as to when CTBTO stations would detect the plume from the Fukushima plant. The animated gif is here.

and seems to show a pretty good fit with regards to when the stations would detect elements given the new simulations. Finally, an NOAA HYSPLIT model is currently being run by somebody which seems to give similar result with regards to particle trajectories. It is here. 

Fukushima: Ibakari Analysis for March 21st.

I wanted to come back to an dose rate increase in Ibakari that occurred on March 21st at 10:00 am. From here:

According to the TEPCO press release on March 20th, the only event I could find is the cooling of the spent fuel of reactor 2:

Cooling of Spent FuelFrom 3: 05 PM to 5: 20 PM on March 20th, 40 tons of seawater was injected into Unit 2 by TEPCO employees.

The Texas A&M maps show the trajectories at about that tine (3PM JST)

On the 22th, at 21:00 JST on March 22, there is a drop, that coincides with a westerly wind. Then the dose rate goes up as the winds comes back to the Ibakari region. So it looks like from the information currently available, the cooling of the pool in reactor 2 and attendant vapor generation might be responsible for this increase in dose rate in Ibakari.

Fukushima: TAMU Forecasts March 30th, Source term around the plant.

The Texas A&M forecasts are in for tomorrow Wednesday March 30th:

Wednesday, March 30

1. • 2011-03-30 12Z - forecast only
2. • 2011-03-30 06Z - forecast only
3. • 2011-03-30 00Z - forecast only

Let us note that 06Z means 6:00 GMT or (6:00 + 9:00) 15:00 JST

From the IAEA press release:

Fukushima Daiichi Nuclear Accident Update (28 March, 23:00 UTC)

Japan Confirms Plutonium in Soil Samples at Fukushima Daiichi.After taking soil samples at the Fukushima Daiichi nuclear power plant, Japanese authorities today confirmed finding traces of plutonium that most likely resulted from the nuclear accident there. The Nuclear and Industrial Safety Agency told the IAEA that the Tokyo Electric Power Company (TEPCO) had found concentrations of plutonium in two of five soil samples.

Traces of plutonium are not uncommon in soil because they were deposited worldwide during the atmospheric nuclear testing era. However, the isotopic composition of the plutonium found at Fukushima Daiichi suggests the material came from the reactor site, according to TEPCO officials. Still, the quantity of plutonium found does not exceed background levels tracked by Japan's Ministry of Education, Culture, Sports, Science and Technology over the past 30 years.

It is important to realize that plutonium is already in the background in large part because of atomic weapons test performed in the 1950s and 1960s in the atmosphere. These tests released plumes of these materials in the atmosphere. The TEPCO/Fukushima anlysis shows specifically that these soil samples have elements of the reactors as the composition of fissile material is different from the atmospheric tests of the 50-60s. From  wikipedia, here is historical account on the truely known toxicity of Plutonium:

....Several populations of people who have been exposed to plutonium dust (e.g. people living down-wind of Nevada test sites, Hiroshima survivors, nuclear facility workers, and "terminally ill" patients injected with Pu in 1945–46 to study Pu metabolism) have been carefully followed and analyzed.

These studies generally do not show especially high plutonium toxicity or plutonium-induced cancer results.^[88] "There were about 25 workers from Los Alamos National Laboratory who inhaled a considerable amount of plutonium dust during the 1940's; according to the hot-particle theory, each of them has a 99.5% chance of being dead from lung cancer by now, but there has not been a single lung cancer among them."^[94][95]...

Fukushima: Timelines, the Fog of Data, Comparing the DOE data and Texas A&M's simulations, Forecasts

The Neutroneconomy blog has an update on Dose Readings in Japan.and provides some analysis of the plumes and their detection. Also via the Neutroneconomy blog, R.C Hoetzlein provides a very nice timeline.

There is another one on the NYT.

Having a good timeline should allow us to make a better comparison with the Texas A&M simulations and readings on the ground. To the untrained eye it looks like there is only one set of sensors. However, the fog of data is fed from are several sensor networks. There are:

• The MEXT ( SPEED! network ) via Marian Steinbach's effort on the Japan Radiation OpenData
• Geiger Crowd network (contribute data and software here)
• Local prefecture networks as featured in this site.( Radiation Levels for Tokyo, Chiba, Saitama, Ibaraki, Tochigi, Gunma, Yamagata, Miyagi, Iwate )
• RDTN.ORG, uses SPPED! data and other networks
• Radiation Crowd Map.
• TEPCO readings (Thanks NeutronEconomy) only in Japanese it seems.
• Citizen centered networks linked to the internet through entities like Pachube (Pachube also get information from the SPEED! network thanks to Marian Steinbach's effort). This last network has issue on its own when it comes to getting peoples's sensors to the network. It includes the need for getting digital information from analog Geiger counters.

Beside the atmospheric ground measurements, there are also tap water measurements (see graphs).

We have updated a google maps featuring the MEXT data and some other data we  mentioned in the blog before:






View Fukushima Plume (Sensors and Measurements) in a larger map


The Radiation data from the SPEED! network can also be found on this map.

With regards to the source term, the Fukushima Dai-ichi plant, Cheryl Rofer  has a take on the white smoke coming out of the plant:

The puffs of smoke that have caused temporary evacuations of the control rooms have not been accompanied by increases in radiation. A gray or black color could indicate a fire, while white “smoke” is more likely steam.

From the FEPC reports, the spent fuel pools at Units 2, 5, and 6 are at acceptable temperatures. Water is being added to the pools at Units 3 and 4, but no temperature is given. The reactor cores in Units 1, 2, and 3 remain partially uncovered by water, but the fact that their containment is holding pressure suggests that there are no large breaches. 

Marian Steinbach has started putting the readings she obtained from the SPEED! network into a small video. This is outstanding. If we could include all the data from all the sensor networks and have a similar video from the plumes, I am sure we could begin to infer something

Here is the SPEEDI Radiation Data Animation - Draft (Mar 20, 00:00 to Mar 23, 15:20 UTC)

As I was looking at the trajectory computations by the fine folks at Texas A&M and the aerial assessment provided by DOE yesterday, I am in need of an explanation: Namely, if you look at the DOE measurements, there is red corridor going up on the left of Fukushima Dai-ichi:

yet when one check the Texas A&M simulations, only a period of potentially six hours provided this region to the exposure to the plume.namely:

The three days worth of simulation by Texas A&M and covered by the DOE survey are:

Saturday, March 19
• 2011-03-19 18Z - analysis + forecast
• 2011-03-19 12Z - analysis + forecast
• 2011-03-19 06Z - analysis + forecast
• 2011-03-19 00Z - analysis + forecast
Friday, March 18
• 2011-03-18 18Z - analysis + forecast
• 2011-03-18 12Z - analysis + forecast
• 2011-03-18 06Z - analysis + forecast
• 2011-03-18 00Z - analysis only
Thursday, March 17
• 2011-03-17 18Z - analysis only
• 2011-03-17 12Z - analysis only
• 2011-03-17 06Z - analysis only
• 2011-03-17 00Z - analysis only

Finally, here are the new Texas A&M forecast for today and tomorrow (times are in GMT).

Friday, March 25
• 2011-03-25 12Z - forecast only
• 2011-03-25 06Z - forecast only
• 2011-03-25 00Z - forecast only
Thursday, March 24
• 2011-03-24 18Z - forecast only
• 2011-03-24 12Z - forecast only
• 2011-03-24 06Z - forecast only
• 2011-03-24 00Z - forecast only

Fukushima: Current state of the Fukushima 1 power plant (as of March 18th)

The Japanese Ministry of Economy, Trade and Industry has published a document presenting the current state of the Fukushima 1 (Fukushima dai ichi) nuclear power plant as of March 18th, 15:00 JST).