[Fegasderty]

Press Release (Jul 09,2013)
Tritium Density Result of Water Quality Survey inside the Port of Fukushima Daiichi NPS (Follow-up Information 8)


This is follow-up information on the latest situation concerning the detection of high densities of Tritium and Strontium in the observation hole at the east side of the Unit 1-4 Turbine Buildings of Fukushima Daiichi NPS.

As we have obtained measurement results for the γ nuclides and all-β from sampling performed yesterday (on July 8) in the groundwater observation hole No.1, the groundwater observation hole No.1-1 (east of (on the sea side to) the groundwater observation hole No.1), the groundwater observation hole No.1-2 (south of the groundwater observation hole No.1), and the groundwater observation hole No.2, we release the results.

As a result, cesium-134 and cesium-137 in the groundwater observation hole No.1-2, and all-β in the groundwater observation hole No.2 were detected at high densities compared to the most recent previous analysis results.

Specifically, cesium-134 and cesium-137 in the groundwater observation hole No.1-2 were detected at 9,000Bq/L and at 18,000Bq/L, respectively, which are higher than the past highest values (cesium-134 at 99Bq/L and cesium-137 at 210Bq/L in the sample taken on July 5). All-β in the groundwater observation hole No.2 was detected at 1,700Bq/L, which is higher than the past highest value (260Bq/L in the sample taken on July 1).

No significant change was found with the other measurement results compared to the previous results.

Upon obtaining the measurement results for tritium in these locations, we will release them likewise.

We are continuing to tackle this problem in such manners as to intensely bring forward implementation of contamination prevention measures such as foundation improvement work to the bank protection, and comprehensively intensify the monitoring by using the results of additional boring to drill additional locations, and the analyses results on seawater at such locations as the port interior and the water outlets.

<Groundwater observation hole No.1-2>
- Sampling on July 8:
Cesium-1349,000Bq/L
Cesium-13718,000Bq/L
All-β890,000Bq/L
- Sampling on July 5 (previously announced):
Cesium-13499Bq/L
Cesium-137210Bq/L
All-β900,000Bq/L

<Groundwater observation hole No.2*>
- Sampling on July 8:
Cesium-134ND (0.49Bq/L)
Cesium-1370.74Bq/L
All-β1,700Bq/L
- Sampling on July 4 (previously announced):
Cesium-134ND (0.39Bq/L)
Cesium-1370.46Bq/L
All-β93Bq/L

For the past sampling results, please refer to the following page on our website:

*This sampling location has been corrected from "Groundwater observation hole No.1-1". We apologize for the mistake. (Corrected on July 10, 2013)

[9mm_fan]

All-β 900,000Bq/L was actually higher Friday than the 890,000Bq/L measured Monday 3 days later. Even with these numbers, it comes out to 67 bananas (~90% of K-40 decay is β decay, thus the slight derating from 15 Bq to 13.5 Bq per banana). So if instead of a liter of groundwater there were 60 bananas they would measure the same all-β values. I don't know how many liters of groundwater there is there, but I'd now be more concerned about King Kong showing up than Godzilla.

[brraverishhh]

The banana equivalent dose is dishonest for several reasons:
1) Banana radiation comes from an isotope of potassium which occurs uniformly throughout all terrestrial potassium. Through homeostasis, the human body maintains relatively constant levels of potassium and thus the radioactive potassium isotope as well. Key point: you cannot raise the level of radioactivity in your body by eating bananas nor other potassium rich foods, at least not for more than several hours, rather you excrete the excess. This is not the case with other forms of radiation, see below.
This is the main way the banana "argument" is dishonest and disingenuous.
2). Potassium 40 (the isotope) also has a long half life in the billions of years. The qualitative aspect of this type of radiation is low. An equivalent level of strontium 90, say, is much worse for the body.
Unlike potassium 40, other nastier isotopes (iodine 131, cesium 134/7, sr 90, etc) can and do accumulate in the body. It isn't so much a single dose with these nasties that hurts, but rather how the biological concentrations increase with time and exposure. Bananas do not give one this kind of accumulating dose, see 1 above

tl;dr. Banana equivalent dose is dishonest. I can eat bananas morning day and night and not increase the amount of radioactivity in my body. If I drink Fukushima groundwater morning day and night, the radiation accumulates and will almost certainly kill me in the long run.

[NeroASERCH]

Also, his math is wrong. 900000/15 is 60000, not 60.

[tgs]

Those are very dangerous levels. You can get diabetes if you eat that many bananas.

[Ifroham4]

That's a great point that is often glanced over. The 15 Bq number is based on banana ingestion and would decrease significantly with distance from the banana.

[Beerinkol]

All-β 900,000Bq/L was actually higher Friday than the 890,000Bq/L measured Monday 3 days later. Even with these numbers, it comes out to 67 bananas (~90% of K-40 decay is β decay, thus the slight derating from 15 Bq to 13.5 Bq per banana). So if instead of a liter of groundwater there were 60 bananas they would measure the same all-β values. I don't know how many liters of groundwater there is there, but I'd now be more concerned about King Kong showing up than Godzilla.

I don't even know what I just read.

[S.T.D.]

Bananas contain trace amounts of radioactive isotopes of potassium, and are still considered safe to eat.
Basically, we're not talking about very high levels of radiation here, is the joke.
I don't know how accurate the numbers or actual health effect estimates are, but that's what OP's getting at.

[Slonopotam845]

I haven't checked OP's numbers either but Bananas (or Banana Equivalent Dose) is an actual non-standard unit of radiation dose. I've found it to be a convenient unit since the dose levels I work with tend to be on the order of a few bananas.

[Fegasderty]

I hope you actually use the unit in your work and not as a tongue-in-cheek way to describe radiation levels to the uninformed.

[Slonopotam845]

I do actually. Once I realized that the unit existed, there was no question that I would be using it exclusively. Of course when I produce anything worth publishing, I convert Bananas to Sieverts.

[softy54534]

For those wondering, this means some wildlife will be exposed to harmful levels of radiation, though the zoological impact will be complicated. Since water is insulating, and large volumes dilute, the ocean and it's inhabitants are unlikely to receive significant exposure, however amphibious animals adapted to land and water, such as lizards, will likely be inundated with very high levels of radiation.

[Fegasderty]

What worries me is that they don't know the cause of the spike. I guess there is more to come...

[9mm_fan]

Potentially "tens of thousands of tonnes of it".
BBC News - Fukushima disaster: Long road to nuclear clean-up

[brraverishhh]

Indeed. Look at what happened in Three Miles Island:

Operators halted the meltdown before the fuel core melted through the containment vessels and supporting cement pads. If the core had come in contact with the relativity shallow water table, groundwater would have instantly vaporized, causing explosions and sending up a plume of radioactive steam. Nuclear Disasters and Groundwater | GroundwaterGo

The groundwater radioactivity rising so quickly suggests to me that there might be a core melting himself through the earth and already being quite close to the water. But then again I don't know much about such things and they'd never let that happen, right?

[NeroASERCH]

a core melting himself through the earth

That doesn't actually happen. A core can only remain critical when the material is relatively pure and surrounded by moderating material ( usually graphite or water ). If the core started to melt its way through the reactor pressure vessel and concrete floor it would mix with the material it is melting its way through, which stops the chain reaction. Furthermore, as the core flows its geometry would be distorted away from optimal and likely shut down the chain reaction long before it had any chance to even reach the ground. This was observed at Chernobyl, and we even have pictures of what happens when corium melts its way through the reactor. What you see there is corium that has solidified in the basement of the plant, after the reactor had a meltdown.
The decay of fission products can still produce a lot of heat many days after the reaction has stopped, but not enough to melt its way down to the water table, and certainly not this long after the accident.
A much more plausible explanation is that contaminated water from the containment is leaking through the floor. That would also be consistent with experience from other accidents. The containment was simply never designed to hold large quantities of water like this, so it is not surprising it is leaking.

[tgs]

What worries me is that they don't know the cause of the spike. I guess there is more to come...

I couldn't agree more. We spend billions upon billions of dollars, countless man-hours of research into materials engineering and safety procedures preventing something like this from happening, which is great. In fact MODERN nuclear power is remarkably safe. There seems to be an incredibly (apparent) stark contrast in answering questions about what exactly is happening there now. Obviously the corium has breached containment but nobody seems to even have an educated guess as to where it is or what to do about it. While the danger is low (for now). I almost can't blame the conspiracy theorists out there (though i'm certainly not one myself), with how much is unknown, it reaches a level of ignorance that seems almost purposeful

[Ifroham4]

I couldn't agree more. We spend billions upon billions of dollars, countless man-hours of research into materials engineering and safety procedures preventing something like this from happening, which is great. In fact MODERN nuclear power is remarkably safe. There seems to be an incredibly (apparent) stark contrast in answering questions about what exactly is happening there now. Obviously the corium has breached containment but nobody seems to even have an educated guess as to where it is or what to do about it. While the danger is low (for now). I almost can't blame the conspiracy theorists out there (though i'm certainly not one myself), with how much is unknown, it reaches a level of ignorance that seems almost purposeful

[Beerinkol]

They do not know what is going on because they cannot go inside the buildings. like 1 hour inside is a lethal dose.

[S.T.D.]

Radiation? For fucks sake, this is JAPAN, send in the remote operated machines.
Throw a ton of money at the problem, and we will know more and may be able to resolve the situation. Japan drags its feet because it will cost a shitload to cleanup, politics, refusing international help, and willingness to let Tepco deal with it.