Oct 15, 2014 UPDATE: “[…} Strontium-90 shatters previous record by over 5 Billion Bq/m3 […]” – ENEnews Oct 15, 2014
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Alamosa, Southern Colorado (USA), Sept. 25-26, 2014.
Checking my Nuclear News sites today prompted me to do some more research regarding the increase of the dangerous radioisotope Strontium-90, sharply on the rise in the on-site groundwater at the Fukushima-Daiichi nuclear disaster site since last year. (Troubling data and likely implications, further below)
Strontium-90 (Sr90) is a synthetic radioisotope, which once inside the body, closely mimics calcium in its biochemical behavior. This causes much of inhaled/ingested Sr-90 to be deposited into bones and bone marrow. Being locked away in this fashion allows it to cause bone cancer, cancer of nearby tissues and leukemia.
Not sure about the new drinking water standards (I read that the White House recently weakened these standards severely, see here, but found no additional more credible sources to confirm this yet), but according to the old EPA guidelines for the maximum legally allowable contaminant levels in drinking water, Sr-90 is almost 25 times more dangerous than Cs-137:
- Tritium = 741 Bq/L
- Technetium-99 = 33.3 Bq/L
- Cesium-137 = 7.41 Bq/L
- Stronium-90 = 0.30 Bq/L = 300 Bq/m^3
- Iodine-131 = 0.11 Bq/L
(See Radiation Units and Conversions if you want to use picoCuries or other units, rather than the Becquerel unit used internationally.)
Strontium situation at Fukushima-Daiichi NPP further deteriorates…
The level of Strontium-90 in on-site groundwater has astronomically skyrocketed even further from the record levels reported in my Aug 28, 2014 Fukushima News update, Fukushima Nuclear News Roundup (Aug. 2014): Some progress amidst worsening groundwater contamination.
My “conclusion” then, that, “the on-site (local) ground water contamination is worsening still; Most troubling are significantly rising Strontium-90 levels” is sadly confirmed in Tepco data about a Sept 15, 2014 sample from the F1’s 1-17 borehole sample site, published September 18, 2014 – which compares to the data from May 12, earlier this year:
- The data from May 12, 2014: 5,600 Bq/liter (= 5,600,000 Bq/m³ (which I usually write as Bq/m^3)) of Strontium-90. See my Radiation Units & Conversions page for more details on the activity unit “Becquerel”, etc.), shows hard evidence that Sr-90 levels, a major Beta-radiation emitter, comprise up to a whopping 96.5% (more than 95%) of Gross Beta levels (!). See the data @ http://www.tepco.co.jp/en/nu/fukushima-np/f1/smp/2014/images/2tb-east_14091002-e.pdf
- The most recent data release, however, shows the above May 12, 2014 Strontium-90 data (no September 2014 Sr-90 data just yet, they may add that in a few weeks when they’ll likely get those Sr-90 lab tests back, or – TEPCO-style – in a few months or even years from now…), but the recent Sept 15, 2014 Gross Beta data suggests a Strontium-90 nightmare is unfolding on-site as we speak, with new peak levels at the same groundwater test site (1-17) of 695,000,000 Bq/m³ of Sr-90 (implied). See the data at @ http://www.tepco.co.jp/en/nu/fukushima-np/f1/smp/2014/images/2tb-east_14091801-e.pdf, highlighted again with red as my emphasis added to the screenshot:
–> This info was relayed last weekend by ENEnews on Sept 20, 2014 under the title, “Japan Times: Fukushima plant plagued by problems as radioactive material bleeds into Pacific — Radiation level in groundwater now 25,000 times higher than when year began”:
[This new information] “reveals strontium-90 concentrations are at record levels in groundwater just 100 feet from the ocean. Gross beta has risen to 720 million becquerels per cubic meter (Bq/m³)
[Gross Beta: 720,000,000 Bq/m^3 –> 95% of which is 684,000,000 Bq/m^3 ]
— and according to Tepco’s most recent strontium-90 tests released September 10 (4 months after the samples were taken), strontium-90 comprises over 95% of the total gross beta at this location — resulting in a Sr-90 concentration of 695 million Bq/m³. [going by the more precise 5,800/5,600 = 96.5%…] At the start of 2014, 28,000 Bq/m³ of gross beta was detected in groundwater from the same well — now 8 months later, the levels are over 25,000 times greater.”
Note: other previously-mentioned Sr90-GrossBeta ratios vary between 79% and 91%, see ENEnews Dec 2013.
That 8-month difference marks a disturbing 2.5 million % increase in on-site Sr-90 groundwater contamination.
With a spiking of Sr-90 thát severe, the sobering prospect is that… the likelihood that TEPCO’s projection/hope to reduce the leaking of Sr-90 into the Pacific Ocean to 1/40th of 2013 levels “after closure” (in 2015?) (see last image of my Aug 28 blogpost, shown again, left) might have overlooked this terrible scenario… (?).
- It could get even worse…
Not to get doomsday-ish here, but a German study from 1992, modeling a meltdown situation very closely resembling the Fukushima meltdowns, sometimes referred to as the “German Rhine River reactor meltdown simulation”, and known by the title, “Dispersion of radionuclides and radiation exposure after leaching by groundwater of a solidified core-concrete melt (= IAEA link, which doesn’t show you the graphs up front… Those (one shown below) can be found at the IRPA link’s excerpt: http://www.irpa.net/irpa8/cdrom/VOL.1/M1_97.PDF, from which my below annotated size-adjusted screenshots); for reference, the study is by Bayer, A.; Tromm, W.; Al-Omari, I. (Kernforschungszentrum Karlsruhe (Germany)) from the 8th International congress of the International Radiation Protection Association (IRPA8)” [which was held in Montreal in May 1992], gives the following modeled groundwater contamination concentrations release table over time [annotated by me in colors]:
Both the time scale and the activity concentration are graphed on a logarithmic scale. For those unfamiliar with these, here’s an easy comparison graph showing the difference between linear and logarithmic scales (click through for more):
Back to the first graph, I marked the 1000 days in red. For Fukushima 1000 days after March 11, 2011 corresponds (Date Calculator) with Dec 5, 2013. Shortly around this date, this meltdown model predict a very sharp rise in Sr-90 groundwater contamination, marked by a skyrocketing concentration rise of almost 10-to-the-10th-power of what would have been measured recently before.
Here’s a part of the above graph, roughly changed to a linear time line (below). The levels don’t go back to near-zero until somewhere between 40,000 days and 100,000 days after the meltdown event. For Fukushima that translates into “sometime in the 23rd century CE.”:
Let’s have a look what this might mean in terms of contamination concentrations…
Another example of a concentration of Sr-90 content of on-site groundwater was hinted of last year, prior to Dec 2013 (h/t ENEnews Sept 27, 2013) in TEPCO’s Fukushima Daiichi NPS Prompt Report, Sept. 26, 2013: “We would like to announce the measurement results of cesium and all β in the water taken from the groundwater observation hole No.1-16 (on the mountain side of No.1-3 where former observation was performed) located on the east of the Units 1-4 Turbine Buildings, sampled for the first time today on September 26. […] Cesium-137: 2.1Bq/L […] All-β: 400,000Bq/L […]
[95% of which might be Sr-90: 380,000 Bq/L, or 380,000,000 Bq/m^3]
We will continue sampling, analyzing, and monitoring the situation.”
If the 95% ratio of Sr-90 to Gross Beta applies closely enough to be used for more extrapolations, then the 380,000,000 Bq/m^3 of Sept 2013, is comparable to the 684,000,000 Bq/m^3 of Sr-90 of Sept 2014, kinda similar, albeit still showing a rise of 1.8 TIMES (almost doubling), or 180 % rise in 1 year. Problem with that comparison of course is… that the one sample is from borehole 1-16 and the other from borehole 1-17, so not 100% comparable. Although… They are véry close together – see next image on which I highlighted them:
As you can see, 1-17 is a bit closer to the ocean than 1-16. On first impression, what this seems to suggests is that the extremely high concentration of Sr-90 is slowly making its way closer to the shore and increasing on its way there. But, closer examination of other nearby sample points does not confirm this. In fact, when looking at what can be compared, at many nearby groundwater sample points the levels have markedly dropped in the same period:
To indicate this on the same map shown above, shows that TEPCO may actually be telling the truth (-Their educated guesses may not be like the utter fabricated nonsense they’re known to spew, if you know what I mean. I mean no disrespect, I do think they are doing the best they can given the unknowns and difficult working conditions-) and that the strong observed increases are likely – at least partially – due to blocking escape pathways nearby. Otherwise the other ones nearby would show increasing levels as well:
See, if I only were to check sites that tend to focus on the alarming parts in new data, I would miss part of the picture. Nevertheless, the increase in Strontium-90 is on the increase, and in on-site groundwater this is clearly the case for the past year, regardless of the mitigation efforts’ effect on some sample sites. That’s a fact. So, to get an idea of how the increase may be unfolding it tried to find some earlier data. Unfortunately most can’t be compared very well. I got these:
Looking around for additional pieces of related data from last year, I found: “5 million becquerels per liter of radioactive strontium-90 in a sample from a groundwater well about 25 meters from the ocean last September ” – Reuters, Feb. 13 2014, but the news didn’t give needed specific details, so making comparisons with these data is not really possible with recent data either. (Whoa, though: 5,000,000 Bq/L = 5,000,000,000 Bq/m^3 of Sr-90, 25 meters from the ocean… already 1 year ago!?)
To get an idea of “when Sr-90 first showed up in groundwater”, I went searching around and found this post from EX-SKF, JUNE 12, 2011: “Radioactive Strontium from Groundwater at Fukushima I Nuke Plant for the First Time”, which mentioned, for near F1’s Unit 3’s “Inside Silt Fence”, a sample taken of on-site groundwater (“detected from the sub-drain pits at the Reactor 1 turbine building and the Reactor 2 turbine building.”), measuring on May 16, 2011: 7,600 Bq/L Sr-90 (So already 7,600,000 Bq/m^3 of Sr-90 (!) just two months after the disaster begun…)
From 7.6 million to (nearby) 684 million in just over 3 years, is almost a x100 jump (2 magnitude orders up), over about 3 years. Yet… honestly, to be strictly scientific here, not much can be concluded with these few data points in time and space, I think. For starters, those borehole spots that truly give an idea of groundwater contamination levels (so not just trench or near silt screens) hadn’t been established yet in 2011, so my GUESS is that those early high readings may have included concentrated surface seep-in/run-off. I don’t know. Pitch in if you know more, please. In any case, we CAN look at that German study graph and compare the more recent Sr-90 borehole data, which DO -very strikingly- shoot up just as predicted some 3 years into the meltdown disaster.
You can see (on that German meltdown model graph) that a doubling (from 1 x 10^2 to 2 x 10^2) might take about a year, and the doubling from 3.8 x 10^8 to 7.2 x 10^8 could happen even faster. To go from the 10^8 concentration to the 10^10 concentration looks like that could happen -very roughly- within a few years as well. The graph is low-resolution and appears hand-drawn, so estimates are not precise. But what you CAN see is that it takes almost half of the graph-distance between 1,000 days and 10,000 days for Sr-90 to go from 10^2 Bq/L to 10^10 BqL.
Half the graph distance on a logarithmic scale is about a quarter on a linear scale, or in this case a quarter of (10,000 – 1,000), with is 1/4th of 9,000, = 2,250 days, or: for Sr-90 levels to peak might take… till 2020, the next 5-6 years… Hindsight will be 2020 alright…
IF my interpretation of the graph, as well as the similarity/correlation between this Rhein River meltdown model and the actual Fukushima meltdown disaster correspond closely and as-such comparable (big if, and it would take an expert to figure that out with accuracy, I think), THEN the Sr-90 release levels are projected to reach their peak contamination release levels (not even saying anything about the cumulative levels if they manage to seal the site!) by the winter of 2019-2020.
By 2020, the Sr-90 on-site groundwater contamination levels would thus become some 1 to 10 million times more severe that they are now (in Sept. 2014).
If the leaks from the on-site groundwater to the Pacific Ocean aren’t sealed soon, then even if the leaking percentage dropped to 1/40th of 2013, the Ocean contamination, due to the skyrocketing Sr-90 concentrations, would actually rise again, quite likely to unprecedented levels…
According to the same model, man-made radioisotope Cesium-137 (Cs-137) will rise sharply too, by a magnitude change of 10,000 to 100,000 x the levels seen so far, and this after some 10,000 days (= just over 27 years), thus – IF this model applies as such – Cs-137 is predicted to peak in on-site groundwater roughly around the year 2038, some 24 years from now… That’s a troubling prospect given the levels are already so high on-site.
In early 2014, Cesium-137 levels in groundwater rose to 54,000 Bq/L (ENEnews, Feb. 13, 2014). If this dire model prediction holds true for Cesium as well, and a rise to- let’s say 10,000 times these max. 2014 groundwater levels, 540,000,000 Bq/L or 540,000,000,000 Bq/m^3 – are to be found in the on-site ground-water by 2038…
This would mean that the entire underground local aquifer would get similarly contaminated as the already much more concentrated trench water ever was. I’m not sure what volume of such extremely contaminated groundwater we’re taking about here, but its calculated contamination concentration would thus be about 1/3rd of the worst trench water found in summer 2013 (then stressed in my Red Alert post from the end of July 2013, or the WSJ’s July 27, 2013’s reporting on this, both mentioning the 1,600,000,000,000 Bq/m^3 of Cs-137 in the troubled trench water back then.). It’s disturbing to imagine we might see the day that these levels occur not just in a few relatively manageable trenches, but in the aquifer itself and permeating the soils underneath the entire site… and likely beyond, possibly far beyond, given much of the on-site geology consists of porous ground and sits on top of a seismic fault line, pretty much guaranteeing that any containment is temporary at best…
Also going by the same model, Technetium-99 (TC-99) would have already flat-lined by now. Wikipedia: 99T “is an isotope of technetium which decays with a half-life of 211,000 years to stable ruthenium-99, emitting beta particles, but no gamma rays. It is the most significant long-lived fission product of uranium fission, producing the largest fraction of the total long-lived radiation emissions of nuclear waste.”
- Countermeasures? Fascinating: what this German model suggested in the early 1990s is exactly what they’re attempting to do: [see shown excerpt, below]:
Hard to imagine, but this nuclear disaster could get A LOT more serious than is currently let on by current TEPCO management and the Japanese government.
Comments welcome. I’ll make adjustments as needed. Please read my DISCLAIMER before commenting.
Sept 26, 2014 (Sr-90 basics added, other borehole data compared as well) Sept 28, 2014: linear approximation of graph added.
Oct 14, 2014: update added at top]