[MAXIMUM ALERT] Fukushima Fallout Indicative of Neptunium 239 Again Hits the Western and North Western United States.
The Fukushima Fallout detected in Saint Louis, Mo on 10/12/11 contains radioactive contamination with a half life of approximately 2.4 days. The measured half life is indicative of Neptunium 239, which decays into harder to detect Plutonium 239. Based on Jet Stream patterns we expect that fallout concentrations were significantly higher in the Western and Northwestern states.
The specific identification of Neptunium 239 does contain an element of uncertainty; however, prudent cost effective risk mitigation actions are strongly indicated. Primary of such actions is to wash contaminated vehicles in a brushed car wash before allowing such vehicles to be parked inside of a habitable building.
Attached below is a graph of the longer half life component of this detection. Further analysis of the decay products is on going.
You're doing great work here with limited equipment - I think everybody should be reading your updates. I'm still not totally convinced, but I'm convinced enough that I'd like to see the results of more robust measurements. (Meaning, using more expensive tools.) This is no knock on what you're doing. Isn't this what we pay the EPA for?
ReplyDeleteThe two questions I have are:
1) What's the variability of the background level measurement? You've drawn it as a thin line. Doesn't it have some daily or weekly variability?
2) Couldn't you get more counts by using a larger sample? (I understand that more counts = more hazard.)
Best,
Aaron Datesman
Certainly Madame Curie did much more with much inferior equipment.
ReplyDeleteWhen you say you are not "totally convinced", do you mean:
(1) You aren't convinced people should take prudent cost effective risk mitigation actions ?
(2) You aren't convinced that longer half life fallout is in the sample?
(3) Or, you aren't convinced of the identification of Neptunium 239.
In regards to the EPA, we do not pay them. Their customer is who ever gives them the money. It is a fact that should not be convoluted with the delusion that we are their customer just because the money given to the EPA was taken from us.
Moreover, all we have seen from the EPA is obfuscation. The clearest example of that is that shortly after the public became aware of the Fukushima Plutonium detections on the RadNet database, the EPA rigged the RadNet database query to return every Plutonium detection ever made regardless of the time period specified in the db query.
With respect to the background average line, you may judge its variability during that time period from the raw Np-239 data presented, as the background variability is a subset inherent in that data.
In regards to getting a larger sample, the paper towel wipe method we are using is actually self limiting in terms of how much it will concentrate the fallout. In order to get a larger more concentrated sample we would have to boil off rain water into an area that matched the detection window of the Geiger counter. Obviously, boiling off radioactive fallout laden rain water in the house is not something we wish to do.
Madame Curie did much more with much inferior equipment, but she started with many tons of ore!
ReplyDeleteMy skepticism mostly lies in the area of (3), I'm not convinced that the signal must indicate neptunium. The modeling I began on an earlier detection you posted taught me that the Sr->Y series can give a signal with a single decay constant around of around 48 hours. This value is adjustable, however, depending on the ratio of [Y]/[Sr] in the original sample. So fitting a curve in this instance does not convince me that it must be Np you are measuring.
What's more, in this instance, what you show is a very noisy signal at a level quite close to background, to which you fit an exponential curve. I trained in electrical engineering - this is not very convincing. If a second measurement with twice the volume of sample gave twice the count rate over background, then my skepticism would fall dramatically.
Of course, it would be foolish to bring these materials into the kitchen to work with them, with the intention of amplifying the measurement SNR. I agree with you.
I have agreed with the takedowns of EPA and the Cal nuclear engineering department in earlier posts; and I don't disagree about whom the EPA works for. (On the other hand, I'm a scientist with the Department of Energy, so don't dismiss the idea that you might find receptive ears in unlikely places.)
An approach which would nail this question might be to appeal to the Department of Energy - perhaps one of the synchrotron facilities would be willing to run samples looking for trace radioactive contaminants. I have contacts who could help get this done.
Madame Curie didn't have the "benefit" of Fukushima concentrating the ore for her, lol.
ReplyDeleteAs stated in the video, NP-239 is not a certainty but is strongly indicative, where as the need for risk mitigation is a certainty. I would like to have a higher signal to noise ratio, but one works with what one has.
The noise does increase the uncertainty of the half life, however that uncertainty is bounded by the limited number of candidate isotopes and what is known to have been released from Fukushima. Of course, as any good EE would know, its the population statistics of the background noise vs signal over time which really bounds the case.
In that light, and given your work on the data, Yttrium is certainly a possible candidate; the coming seasons wheat crop yields in the "grain belt" will give some indication if it is Yttrium. However, the lack of Strontium decay curve indications in the sample would tend to preclude Yttrium.
In regards to the DOE, I wager that there is a high likelihood any significant NP-239 detections would at MINIMUM be marked FOUO. However, the presence of an independent observer might help with that potential issue.
Thanks for all your input and feedback, the more capable eyes looking at the data the better.
I realize now that what I was suggesting wasn't very clear. DOE runs its X-ray synchrotron facilities, including NSLS at Brookhaven and APS at Argonne, as user facilities. You can gain access to these facilities by writing a user proposal describing the work and its benefits.
ReplyDeleteHere's an example of someone who did environmental analysis of rainwater samples using an X-ray synchrotron:
http://www.google.com/url?sa=t&source=web&cd=2&ved=0CDEQFjAB&url=http%3A%2F%2Fwww.fec.unicamp.br%2F~silvana%2FAIP.pdf&rct=j&q=synchrotron%20radiation%20total%20reflection%20for%20rainwater%20analysis&ei=gH-dTtrALOOOsQKW4uyMCg&usg=AFQjCNGcrjtxfRQ1RkPyawc4F8s8xa4XjA&sig2=DDXfWmQZgv2yGW7x8GF3lA&cad=rja
DOE staff help design and run the experiment, and there is no cost. There is, however, the hurdle of peer review.
A more promising method of entry would be to incorporate student participation, which might allow you to perform an end-run around peer review of the user proposal process. You could partner with a local school or a professor at a local college to propose the experiment, explain the benefits to community outreach, and ask for help. The light sources do a lot of community outreach and would be receptive.
That certainly is an interesting end run around the risks of a FOUO+ designation. But overall, it does not seem like a cost or time effective gambit.
ReplyDeleteThe travel costs alone would likely cover the costs of purchasing our own RID. Plus there are the time logistics of having a scheduled time available coincide with one of our own positive testing samples.
Moreover, it troubling to even have to try and attempt that rigamarole when the data should already be available somewhere.
In the end, as long as a 80%-90% solution gives good direction for cost effective risk mitigation strategies, there doesn't seem to be a significant value in engaging a large cost increase which only has a minimal rate of return in the given solution space.
However, there are other sample sources under consideration that would potentially return good value for the economic outlay.