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Ocean Radiation and the Fukushima Disaster (deepseanews.com)
79 points by KamiCrit 1420 days ago | hide | past | web | favorite | 31 comments



Really there are two things in this article: First that the folks trying to scare people about radiation lie alot and use misleading graphics to create fear, and two the ocean is a really big place and the source of radiation (primarily Cesium-137 and Cesium-134) are not harmful in the quantities detected.

She missed pointing out the hundreds of nuclear bombs that were detonated in the sea water around bikini Atoll in the 50's and 60's which didn't kill the west coast.

But none of that really matters. It is an emotional fear not a rational fear that the exploiters play on. No amount of reasoning will get through that.


"She missed pointing out the hundreds of nuclear bombs that were detonated in the sea water around bikini Atoll in the 50's and 60's which didn't kill the west coast."

Specifically: nuclear testing released about 30 times more Cs-137 (in particular) than Fukushima, also mostly into the Pacific. An estimated 25 MCi [0] = 925 PBq, vs. 23-50 PBq [1].

[0] http://books.google.com/books?id=JLFX6EMPqBkC&pg=PA34

[1] http://www.pnas.org/content/109/16/5984.full

(copied from an older HN comment I wrote)


I thought the bigger problem with Fukushima was not the Cs-137, but the Sr-90.


I don't think Fukushima released much strontium (do you have a source otherwise)? The atmospheric release concentrated elements with high vapor pressures, in particular iodine and cesium.

edit: Here's a paper [0] which measured Sr-89 and Sr-90 in seawater near Japan: they found a ratio of about 0.026 of Sr-90 : Cs-137 -- relatively little strontium. Their estimate for total Sr-90 released is 90-900 TBq, corresponding to Cs-137 release estimates of 3.5 - 35 PBq. The figures for Chernobyl [1] are 10 PBq and 85 PBq respectively -- that is, Chernobyl released 10-100 times more Sr-90 than Fukushima. The Sr-90 : Cs-137 ratio was even higher (0.63) for atmospheric weapons tests: 600 PBq Sr-90, 900 PBq Cs-137 [2].

edit2: Made a table:

               Sr-90 [PBq]  Cs-137 [PBq]  ratio  ref
    Fukushima  0.09 - 0.9   3.5 - 34      0.026  [0]
    Chernobyl  10	    85            0.12   [1]
    Weapons    590          930           0.63   [2]
[0] (pdf) http://www.biogeosciences.net/10/3649/2013/bg-10-3649-2013.p...

[1] (large pdf) http://www.unscear.org/docs/reports/2008/11-80076_Report_200... (table 1, page 9)

[2] http://books.google.com/books?id=JLFX6EMPqBkC&pg=PA34


However, Strontium-90 which gets into bones and was released into the atmosphere by those bombs, was detected everywhere in USA, in the teeth of children (baby teeth), see for instance http://en.wikipedia.org/wiki/Baby_Tooth_Survey

Aside: until Fukushima is well and truly contained, the possibility of something catastrophic happening is still present.


You're conflating possible with probable. Many things are possible with a probability approaching infinitely improbable. Something catastrophic and highly improbable already has happened, and three years later still approximately 0 (zero) deaths from radiation. Probability theory suggests the chances of another catastrophic event occurring at the same site are much smaller than the first set of events.


I don't want to nitpick but probability theory doesn't care that the event already happened at the site. So presumably the risk of another tsunami coming in or a major earthquake is pretty much unaffected by the fact this specific site already had seen a major disaster... I guess the site itself has changed and that means something in the terms of the probability curve, e.g. it can't get much worse or something along those lines...


Earthquakes are caused by two continental plates releasing tension as they slip past each other. Earthquakes (and therefore tsunamis) are not independent events, and strong quakes are unlikely to occur in close succession.

Probability theory defers to physics.


As someone who lives in an earthquake zone I think this theory isn't consensus by any means (that earthquakes release tension and reduce the probability of a followup earthquake). That is no one actually knows if having a strong or a weak earthquake increases or decreases the probability of having another one. Once we can dissect the earth and model accurately what's going on in there it will become physics, until then it's more like geology... Tsunamis can also be triggered by earthquakes in different locations.

I'll agree with the part that earthquakes aren't independent events...

EDIT: "The opposite occurred in Turkey along the great North Anatolian fault. A large quake in 1939 sent stresses farther down the fault, triggering a 60-year series of quakes whose latest installment was the deadly Izmit earthquake of 1999. The stresses have risen in the crust near the city of Istanbul, and a quake there is now considered more likely. " - http://geology.about.com/library/weekly/aa022303a.htm


I think you are confused. The earthquake and reactor accident happened.

That the reactors are not contained, is not a separate event. It is cleanup that has not yet occurred.

You wouldn't say, "Well, I fell off my bike at 25mph on pavement, landing precisely on both kneecaps, which was highly improbable" and then say "the probability that my knee is bleeding is therefore lessened", would you?


In total, she missed 2053 nuclear explosions all over the world: http://www.youtube.com/watch?v=dxyRLvcjVCw


Nonetheless the article is helpful to folks like me who are looking for something concise that puts the numbers in perspective.

Good for cocktail parties.


Keep in mind, the author is an Oceanographer, not an export in nuclear reactors and radiation exposure (as is abundantly clear when reading the article - at one point she suggests that control rods in the BWR class reactor are cooled with seawater - a quick read through http://en.wikipedia.org/wiki/Boiling_water_reactor would have caught that)

She should have probably co-written this otherwise excellent article with a subject matter expert instead of guessing.


"The radioactive rods in the Fukushima power plant are usually cooled by seawater [CORRECTION: they are usually cooled by freshwater. As a last ditch emergency effort at Fukushima seawater was used as a coolant.]."

She corrects herself just fine, but nice job on reading the article.


I think the parent's point is that she made the mistake in the first place at all, which lessens her credibility reporting on nuclear-power-related material.

Which I agree with, but I still feel better about the accuracy of this article over pretty much anything else I've read about seawater contamination due to the Fukushima disaster.


Yes, don't get me wrong. Overall the article was really good, and captured nuance and details on how the Ocean deals with this sort of thing in a way that I haven't seen done before. I just think it could have been an extraordinary article if she'd co-authored with an expert in Nuclear Radiation.

She (slightly) committed the sin of believing that just because she's an expert in Oceanography, that she could also carry water in another scientific field.


As do I.

Being as she is a physical geographer and given that the majority of scare articles have related to the spread of radionuclides and the so-called imminent danger to the west coast of the US (and countless doomsday-style scenarios that have been appearing since the events at Fukushima et al), having someone whose research has focused more or less on precisely the subject at hand is certainly relieving as well as enlightening

I think that's the point of this entire article, though. The scaremongering is being perpetrated by people who generally have no background in either oceanography or nuclear physics [1]. So in my mind, whether she's qualified to talk about the materials released is largely moot. The concern among conspiracists is how this material is going to spread (and purportedly kill us all), and she's more than qualified to explain how such theories are an expression of Chicken Littlisms.

[1] Granted, neither myself nor many of us here have such backgrounds, but I choose to lend greater credence to the arguments of someone who does have such a background.


There seemed to be a recent influx of these articles all over my Facebook feed for whatever reason. While just having a discussion I was pointed to this paper:

"Pacific bluefin tuna transport Fukushima-derived radionuclides from Japan to California" http://www.pnas.org/content/109/24/9483.full.pdf+html?sid=2c...

I'm no scientist, but I found particular interest in:

"Inferences about the safety of consuming radioactivity-contaminated seafood can be complicated due to complexities in translating food concentration in actual dose to humans, but it is important to put the anthropogenic radioactivity levels in the context of naturally occurring radioactivity. Total radiocesium concentrations of post-Fukushima PBFT were approximately thirty times less than concentrations of naturally occurring 40K in post-Fukushima PBFT and YFT and pre-Fukushima PBFT. Furthermore, before the Fukushima release the dose to human consumers of fish from 137Cs was estimated to be 0.5% of the -emitting 210Po (derived from the decay of 238U, naturally occurring, ubiquitous and relatively nonvarying in the oceans and its biota; not measured here) in those same fish. Thus even though 2011 PBFT showed a 10-fold increase in radiocesium concentrations, 134Cs and 137Cs would still likely provide low doses of radioactivity relative to naturally occurring radionuclides, particularly 210Po and 40K."

From my understanding: yes, radioactivity is being transported and yes, the levels are higher. However, the levels are not significant compared to naturally occurring radioactivity that ends up being consumed.

This was a nice read, I look forward to referencing it and some of these comments.


This article has no mention of bioaccumulation. Pacific Ocean is so large that it can dilute huge amount of radioactivity, but bioaccumulation changes the story. Without estimates how well these leaks bioaccumulate, the whole article is useless. Humans are at the top of the food chain in the sea and overfishing and exploiting sea life close to it's maximum capacity.

In Chernobyl, most of the radioactivity fell into the forests, mostly away from human food chain (there are still recommendations to not eat too much berries, mushrooms etc. in many areas). The Pacific is 100% in human food chain.


As ChuckMcM and I point out, Pacific weapons testing released an order of magnitude more Cs-137 in the 1950's. So Fukushima's effects will merely repeat whatever that did to Pacific fishing, on a much smaller scale.


If it has an effect on overfishing then we should welcome it. Sometimes paranoia can be useful. Or there will be no more tuna left for our grandchildren.

Nature does not care so much about radiation than we do. The wildlife in Chernobyl had fared better after the accident simply of not having humans present. Some like Stewart Brand went so far as arguing for placing nuclear waste in dry cask storage into nature preserves. Just to keep them pristine.


Precisely my thought. It's a notable lapse in an otherwise well-constructed article.

And to be clear: calling out specifically how the alarmists have misrepresented radiation hazards (I've seen the wave-height map circulated misleadingly numerous times) is absolutely the right call.


Isn't this article guilty of the same sins it is lambasting others for ie: speculation based on guessing? It's just taking the other side of the argument. I don't see any actual measure of radiation here it's just another model. Can't they just go out in the ocean and monitor the actual levels? Seems like that would settle things.


The amount of radiation released so far is perhaps not a big problem. It's the lack of control and credibility from Tepco and soforth that concerns me. The power plant was designed to ensure something like this couldn't happen and then it did; then various reports about what was under control and then it wasn't... Realistically, when is the flow of highly-radioactive water into the ocean going to stop?


>>although I admit the groundwater itself has extremely high radiation levels<< Am I reading too closely or is this strange language to use when one isn't a spokesperson for the failed plant?


Im not sure what you mean, of course any leaking fluid from the source is going to have much higher levels of concentration before it becomes diluted.


I'm not disputing the statement, I'm pondering the authors choice of words, it's almost like an apology. You don't usually admit to something you didn't do/cause, you just state it.


The funny thing about radioactive materials is that there's a big tradeoff in terms of short-term vs long-term danger.

Say we have two samples of radioactive isotopes, both of equal mass and which produce the same particles when they decay. Sample A has a very short half-life (let's say minutes). Sample B has a very long half-life (let's say centuries). Sample A is much more dangerous right now but, in a few weeks it will be mostly gone. Sample B, having hardly decayed at all, will be the bigger threat then. In a single catastrophic release, as in the case of Fukushima, you'd probably prefer to have a lot of B sent out. It'll be around for a while, but it's not too deadly and will disperse, effectively raising the ocean's background radiation by an imperceptible amount. A huge release of A might do a lot of localized damage. If you have a slow, continuous leak, B might actually be worse though, since it could build up while A will not.

Cesium 137 and 134 have moderate half-lives of 30 and 2 years respectively. Iodine 131 has a shortish half-life of 8 days. It's been 666 days (Gee, I wonder why this is popping up today!) since the Fukushima incident, so the Iodine 131 had now decayed to 0.5^(666/8) or roughly 1e-25 of it's original strength. It's basically gone. The Cesium will be around for a while, but it's a lot less dangerous than the Iodine was.

Funny Aside: Cs-137 is very commonly used in undergraduate student laboratories. Samples of it are relatively safe to handle without safety equipment and it doesn't need to be replaced very often. I once TA'd a lab course where students were asked to do some experiments with CS-137 and, in their write-up's, calculate the effective dose they received. Most got the right answer, but a few messed up their units and wound up with ginormous doses that would have killed a zombified rhinoceros! Some of these students noticed this and reasoned they must have made a mistake, since we probably wouldn't try to kill our students. A couple did get very concerned though! Most just didn't notice, which was a tad depressing for me.


>> Cesium-137 is product of nuclear fission. Before us humans, there was no Cesium-137 on earth.

There's places of natural fission occurrence on Earth, doesn't that mean that they are potential sources of Cesium-137? I searched multiple sites and found no relation between the topic of natural fission sites and either CS-137 or Cesium-137.

Why should this be a product of man-made fission only?


It's only sort of true. One thing to note is that spontaneous fission occurs all the time with naturally occurring U-235, but at extremely low rates such that the buildup of fission byproducts happens only in trace quantities. But if it didn't occur then fission reactors would be far more difficult to build since there wouldn't be a small background of neutrons from fissile materials to be amplified by reactor/bomb designs.

As to natural reactors, those did exist and they did produce Cs-137, naturally. However, those reactors ran only billions of years ago, so the radioactive byproducts, such as Cs-137, have long since decayed.


I can't take this article seriously, an oceanographer inciting people to eat more fish makes no sense in times of over-overfishing.

Any article telling me "you don't have to worry about fukushima because chernobyl was worse" is suspicious to me. It's the same as saying you shouldn't be concerned about this war, world war 2 was worse.




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