New sludge data from Japan shows recent increases in iodine-131. This suggests increases in fission, probably from Units #2 and #3. Certainly the plant has become more active in emissions lately. The CSFP has been emitting steam and smoke, but hopefully this is not the source of I-131. We would be in very bad trouble if that pool went critical.
Deposition of I-131 is dependent on wind direction and precipitation (rain and snow). This map below shows the locations of the prefectures in Japan. The Fukushima Daiichi plant is on the coast in the middle of Fukushima prefecture. Gunma is furthest west… winds seldom blow from east to west in winter. In spring and summer this prefecture has prevailing winds from this direction, and hence readings tend to be higher there in those months.
And Tepco has found a fault in their radiation measuring apparatus. It turns out that groundwater from the well at the seaside direction from Unit 2 has a lot more strontium-90 and all-beta radiation than they previously said. It used to be 900,000 Bq/liter, now it’s 5 million Bq Sr-90 and 10 million Bq all-beta. And this was from July. This same well had the incorrect analysis of all-beta going from 900,000 to 3,100,000. Applying this ratio yields over 17 million Bq/liter of strontium-90 in the most recent measurement.
Tokyo Electric Power Co. corrected its radioactivity readings for groundwater from a well at the crippled Fukushima No. 1 nuclear plant to a record-high 5 million becquerels of strontium per liter.
TEPCO officials said the strontium levels were gauged again because the previous data was wrong. They also said radioactivity readings for water taken from other wells before September were also likely erroneous.
The company had said 900,000 becquerels of beta-ray sources, including strontium, were detected in water taken on July 5, 2013, from the observation well near a water intake for the No. 2 reactor turbine building.
The new strontium data indicates that the concentration of all beta-ray sources totals around 10 million becquerels per liter of water, according to the company.
TEPCO did not announce radioactivity levels of 140 samples of groundwater and seawater taken between June and November after it found strontium readings that were higher than measurements for all beta-ray sources.
The company attributed contradictory data to malfunctions of analytical equipment. (link)
How convenient that they had an equipment breakdown before the Olympics were awarded to Tokyo.
Regarding the delayed disclosure of data, Tepco stated they were taking time to investigate the cause of wrong analysis. However after all, they didn’t release the data, which strongly suggests the on-going sea contamination, before IOC selected Tokyo as the host city of Olympic 2020. (link)
Enenews had previously linked to this pdf, which was a simulation of three different radionuclides leaking from corium to groundwater. Strontium-90 doesn’t start leaking in significant quantities until 1,000 days after the meltdown, which was approximately the time frame from last July. Cesium-137 doesn’t really get going until after 10,000 days. This is consistent with the finding of large amounts of strontium and other beta, but very little cesium in the well. According to the graph, it keeps going for 297 years. After that, these radionuclides would have decayed. The graph doesn’t contain plutonium, which would keep going for centuries or millenia.