This theory has been put forward by a contact in New Zealand. The Radon-220 decay daughter isotope detection here, is an indication that one or more of the underground coriums at Fukushima undergoing fast neutron fission. One or more coriums are possibly purifying, and operating in a mode of unmoderated fission. This would increase the yields of Thorium daughters.
2. Trace amounts of longer lived isotopes for Iodine I-129, Uranium U-235, Be-7 and Lead Pb-210 where also detected. This is not good, but probably far less than areas in the Northern Hemisphere are getting as fallout.
3. Here are some other theories why large Radon washout events are becoming more common.
Some of the very large Radon washouts that are occurring in Nimbin area may be related to the geography of the location. Why we have concerns about large Radon washout events.
For more Technical details, charts and analysis, read on. (Comments, corrections, and suggestions are welcome)
“Alert Caloundra report 18th September 2013 – Storms overnight here, so I took rain swab off a car this morning. On testing it peaked at approximately 6 uSv/hr (1800 cpm) using two Russian SBM-20 tubes, and Theremino Geiger kit. Again it is suggested to stay out of the rain. This rain sample is decaying quickly which suggests it was a large Radon-222 washout.”
This long period Geiger counter test chart indicated the presence of other Isotopes besides Radon-222 washout decay daughters.
Geiger Counter Test Chart
Explanation of Geiger Counter charts
This swab was placed in the scintillator lead chamber for further testing.
Scintillator test chart
The main peaks are decay daughter isotopes of Radon-220, Lead Pb-212 (238 keV), X-ray at 77 keV, and Thalium Tl-208 (511, 583 keV), plus peaks for long lived isotopes of Iodine I-129, Uranium U-235, Beryllium Be-7, and Lead Pb-210. Because the rain swab scintillator test was started less than 24 hours after it was collected, there are some Radon-222 decay daughter isotopes of Lead Pb-214 and Bismuth Bi-214 also present.
Day average background levels have also been very volatile in this area for last 14 days, recently hitting 30% above the pre-Fukushima 4 year average.
September 2013 day average chart.
Alert Nimbin Monitoring Station report 16th September 2013 – Nimbin is located on the east coast of northern New South Wales Australia.
“…Rain began this morning…. drove to town about midday, got home about 30min ago and sat my SBT 10 on the roof of the car, as I gathered my things out of the back seat, and it started beeping. It was reading 0.38uSv/h….moments later I took a swab off the whole car roof (small sedan) and put it to my LND 7317 and got ~6500CPM for the first few minutes. I’ll send a photo and chart soon….” Here is the decay chart and detection photo of this detection, kindly provided by the Ninbim radiation monitoring station operator.
NOTE: We haven’t seen any studies on the heath effects of being exposed to large Radon washout events like this. It is only a suggestion to take these precautions in the Rain Alert emails. If you live in the area, it is suggested to stay out of the rain during these events, plus keep children and pets out of it also. If you do get wet, have a good shower. It maybe a very large radon washout event, that seems to be common to the Nimbin area. This rain washout could also have other isotopes in it. Without further testing with better equipment, there is no way of knowing.
Another report indicating recent Fukushima releases went far and wide.
“Radiation plume after Japanese earthquake. Iodine-131 cloud reached France.”
Disclaimer: This is an amateur volunteer run service. Human error can provide incorrect information, and equipment malfunction can produce false readings. Do not rely on, or take action upon information presented here, without further research.
09.09.2013 – Detection of radioactive Iodine I-129 in roof gutter moss Australia.
I recently collected 82 grams of moss that had been growing in roof gutter here, and tested it. It was very wet here for the first half of 2013. August has had no rain, so the moss sample was dry.
I am located here on the east coast of Australia.
Moss growing in roof gutter
Moss in Marinelli beaker for testing
Test chart of moss sample using experimental Theremino MCA version 5.
If my assessment is correct, this Southern Hemisphere detection is not a good sign. This is a lot of Iodine I-129. The other possibility is it is Lead Pb-210, or a mixture of both. The main peak is much closer to 40 keV than to 47 keV for lead Pb-210. I have tested this sample with different software, and calibrated a number of times, it very much looks like I-129.
This means it is bio-accumulating. So even though our background levels here have not risen a lot, bio-accumulations could present a more serious issue. The moss also had some other material mixed in with it, that it was growing on, leaves and other organic matter. This test result also suggests that there would be more 1-129 in fallout in the Northern Hemisphere.
I have discussed this test result with some of my contacts here.
Why so much I-129, and not Cesium etc.?
The conclusion is because of its volatility. It can also easily volatilize in an environment, as the temperature increases.
This would allow it to easily spread long distances, like Iodine I-131.
Japanese study of I-129 pre-Fukushima Nuclear disaster.
Another pre-Fukushima Argentina study, indicates that Norther Hemisphere I-129, can reach the Southern Hemisphere. This study shows I-129 has migrated from nuclear fuel reprocessing plants at Cape de La Hague (France) and Sellafield (UK).
For the technically minded – Testing procedures, and Becquerel activity calculations.
Alpha Spectra NaI 818/2B, resolution 7%
Voltage setting; 800 Volts
Efficiency 7% at 662 keV
I used radioactive Americium (Am-241), from a smoke detector in the test chamber, to calibrate the low energy peak position, and also the scintillator efficiency at around 40 keV.
Here is the calibration chart for reference.
Estimate of scintillator efficiency at 40 keV