Monday, September 19, 2011

(Now They Tell Us Series) Groundwater Coming into Reactor Bldg and Turbine Bldg Basements at #Fukushima I Nuke Plant

TEPCO finally admits, after confronted with the calculation by Tokyo Shinbun. To no surprise to anyone but TEPCO, the Japanese government, and probably the majority of the Japanese people, the basement walls and floors are likely to have cracked and been damaged during the earthquake.

If this is true, it's good in one sense. Instead of the highly contaminated water in the basements leaking into the groundwater, the groundwater is coming into the basements...

From Tokyo Shinbun (7:06 AM JST 9/20/2011):

福島第一 建屋に地下水大量流入か 収束作業に難題

Large amount of groundwater flowing into the basements at Fukushima I? Obstacle to the work to wind down the accident

東京電力福島第一原発1~4号機の原子炉建屋やタービン建屋地下に、一日数百トンの地下水が流入している可能性のあることが分かった。汚染水処理の 実績などから計算すると、五万トン強まで減っているはずだが、実際には八万トン強も残る。東電も地下水流入の可能性を認めており、地震で建屋地下の壁が損 傷し、流入していることが考えられる。今後の収束作業に影響が出そうだ。

It's been revealed that there is a possibility that several hundred tonnes of groundwater may be flowing into the basements of reactor buildings and turbine buildings in Reactors 1 through 4 at Fukushima I Nuclear Power Plant. The amount of contaminated water should have decreased by now to slightly over 50,000 tonnes, based on the amount of water processed. However, there are still over 80,000 tonnes of highly contaminated water remaining in the basements. TEPCO has admitted to the possibility of groundwater flowing into the basements, whose walls may have been damaged in the earthquake and are letting in the water. This may affect the future work to wind down the accident.


Tokyo Shinbun calculated the hypothetical amount of the remaining contaminated water, based on the data published by TEPCO on the amount of contaminated water transfer and the amount of water injection into the reactors. According to our calculation, about 100,000 tonnes of contaminated water should have been reduced to about 51,600 tonnes by September 13.


However, the latest estimate by TEPCO from the actual water levels in the basements is 81,300 tonnes, leaving 30,000 tonnes or so gap from the calculated amount.

  東電はこれまで、汚染水がなかなか減らない理由を、雨水の影響と説明してきた。福島第一周辺では、七月以降の三カ月間に三回まとまった雨が降っており、一 部は屋根の損傷部などから建屋に流れ込んだとみられるが、水位の変動は小さく、三万トンの差を説明できるほどではない。

So far, TEPCO has explained that the contaminated water is not decreasing as fast because of the rainwater. Around Fukushima I Nuclear Power Plant, there have been 3 heavy rainfalls since July. Part of the rain may have entered the buildings through the damaged rooftops. However, the contribution of rainwater to the water in the basements is not big enough to explain the 30,000 tonnes difference.


It has been pointed out before that the groundwater may be flowing into the basements through cracks in the basement walls, and now that possibility is even more heightened. We showed the result of our calculation to TEPCO, and they answered "The water may be flowing in in the order of 100 tonnes per day".


If the groundwater is indeed flowing into the basements, the amount of contaminated water to be treated will be further increased, necessitating the decrease of water being injected into the reactors. The work to wind down the accident may be affected in many ways.

I don't know whether TEPCO means "100 tonnes per day per unit" or "100 tonnes per day per each building" or "100 tonnes per day at the plant".

In the latest announcement on the contaminated water processing on September 14, TEPCO is processing about 1,500 tonnes per day.


Anonymous said...

Talk to your friends. Talk to your families. Post these articles EVERYWHERE!!! Tell everyone, ya'll! Japan's citizens need our help and we must protect our future!




Here's the info:

netudiant said...

At 100 tons/day we get only 10,000 tons since June, but 400 tons/day would be too much, as the water level has fallen noticeably.
Of course, the rate of inflow might well increase as the water level in the plant declines, simply because there will be less back pressure. It would be helpful to have data on the level of contamination of the water in the plant, as it should be declining if substantial volumes of clean ground water are diluting the existing contaminated plant water.
Unfortunately, there has been no update to the useful
JAIF summary of the status of countermeasures at Fukushima since Sept 15. The last report was here:
One gets the impression that the available information is steadily diminishing.

Anonymous said...

the rate of inflow might also have a direct correlation with the amount of rainfall in the area and the flow of the ground water. Geology would also play a role in this.

Anonymous said...

It could also leak in both directions, depending the hight of each leak.

Anonymous said...

It most certainly leaks both in and out - this just means that the inflow is bigger than the outflow. Seems to me TEPCO should drill a test well somewhere near the sea.

Anonymous said...

Totally expected, totally tragic.

Anonymous said...

According to, the bottom of the basements of units 2, 3 and 4 are below sea level (O.P. 0mm). In unit one the bottom of the torus is right at sea level. Normally, one would expect the water table to be around sea level, when one is this close to the ocean. Actually, one would expect the (fresh) water table to be slightly higher than sea level or else there is intrusion from the sea into fresh water aquifers, making them brackish. IIRC, when the reactors were built, sump pumps were used to lower the water table around the reactor buildings to keep the basements dry. However, when electricity was shut off due to the tsunami, the sump pumps stopped. It would not surprise me that the sump pumps are still not operational. Unless the basements were built like swimming pools (with air-entrained concrete, etc.), water will go right through the walls - cracks are not necessary. This is no big surprise, as anyone who has owned/built a basement below the water table will know.

Anonymous said...

That's an awful lot of water per day to be coming from groundwater. Groundwater is usually defined as 'seepage'. This sounds like a broken water main. Or do they have a flowing well nearby?

Anonymous said...

Arnie's site in Japanese is mega-annoying. I'm logging in from Japan, and the Fairewinds site defaulted to Japanese. I couldn't get it to go back to English. There is a banner saying "click here for English" but the link is not live yet.

arevamirpal::laprimavera said...

@anon at 3:03PM, I suggest you let them know that. I'll embed the English vid for you later.

Anonymous said...


not only is it a lot, it's also the first time TEPCO has admitted groundwater contamination. And they did so in a big way.

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