Fukushima: Combining information from UC Berkeley, Texas A&M and TEPCO.

There is a new report from UC Berkeley that provides a timeline of the radiation measurements. The report is here:

Of interest today is the peak observed on March 24th (California time = GMT - 9). If one checks the Texas A&M maps, it looks like there is a possibility to connect this peak to a source term around March 20th at around midnight (GMT) or a little bit before.

The TEPCO press release for that time frame show something new that day among other things:

Cooling of spent fuel pools At approximately 8:21 am, March 20th, water discharge to Unit 4 by fire engine has started with the cooperation of Self-Defense Forces.

Or because the graph shows counting performed for the whole day in California (as opposed to actual time period) another later event:

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

The finding seems consistent with any of two source terms occurring at 

• 8:31 AM on March 20th, or about midnight March 20th (GMT) and,
•  3:05PM/5:20PM on March 20th or about (6:00AM GMT March 20th).

 The detection in California has occurred around March 24th (PST) or about March 24th/March 25th (GMT).

Hence it becomes difficult to delineate which of the two source terms was effectively detected at Berkeley. Now let us watch the Tokyo measurements. it shows a start at about 8:00 am March 21st (JST)

which seems consistent with reactor #4 pool cooldown. The second peak seems connected to the reactor #2 cooldown but it could also be connected to the smoke observed on top of unit 3 (March 21), however that would seem unlikely since according to TEPCO environmental readings remained at the same level when the fumes occurred. Once the cooldown is obtained and stable, there is no expectation of further release to the environment. The expectation is now that the radiation measurements should continue decreasing (irrespective of whether the winds are westerly).

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