Wednesday, December 7, 2011

#Fukushima I Nuke Plant: 220 Tonnes, not 45, of Strontium-Contaminated Water?

If you look at the photos released so far by TEPCO (see my posts here and here) while being told only 45 tonnes of treated water leaked from the evaporative condensation apparatus (desalination) at Fukushima I Nuclear Power Plant and that only 150 liters (about 40 gallons) of it leaked into the ocean, and wonder "45 tonnes? 150 liters? The numbers look too low", you may be right.

The amount of water leaked from the apparatus may be 220 tonnes, not 45 tonnes as widely reported. In this case, one of the first reports by Asahi Shinbun (print/digital print version) may have gotten it right. 45 tonnes just inside the building that houses this apparatus.

Let's do some recalculations. 150 liters of the treated water that have leaked into the ocean, according to TEPCO, had 26,000,000,000 becquerels (26 billion becquerels) of radioactive materials (cesium, strontium, etc.). If 750 liters leaked instead (using the ratio of 220 tonnes to 45 tonnes), 130 billion becquerels. If one tonne (1000 liters) leaked, about 173 billion becquerels.

The first news of an event in this nuclear disaster has often proven to be right, just like the March 12 announcement by the Nuclear and Industrial Safety Agency that there may have been a core meltdown at Fukushima. (That spokesman was replaced the next day of course.)

Anyway, here's Asahi Shinbun's report at 10:47PM on December 4, 2011 (print/digital print version):

東京電力は4日、福島第一原発にたまる高濃度放射能汚染水を処理する施設から、水が45トン漏れているのが見つかったと発表した。処理後の水だが基 準を大幅に上回る濃度の放射性物質を含み、漏れた総量は最大220トンと見積もられ、一部が海に流出した可能性がある。東電は原子炉の冷温停止状態を達成 間近としてきたが、一方で復旧作業にはなお手を焼いていることを示している。

TEPCO announced on December 4 that 45 tonnes of water was found leaked at a facility to treat the highly contaminated water at Fukushima I Nuclear Power Plant. The water has been treated, but it contains radioactive materials that far exceed the level allowed by law. The total amount of the water leaked is estimated to be 220 tonnes maximum, and part of it may have leaked into the ocean. TEPCO has said that "cold shutdown" of the reactors will be achieved soon, but this incident shows that there are problems in the restoration work.

 原子炉の冷却水を処理して再利用する循環注水冷却システムで起きた水漏れでは、過去最大の量。漏れた水のセシウム濃度は1リットルあたり4万5千ベクレ ルで、原子炉等規制法が定める海水での濃度の基準の約300倍。ストロンチウムの濃度は測定に時間がかかるので結果が出ていないが、これまでのデータから 分析すると、濃度は1リットルあたり1億ベクレル前後、基準の100万倍あるとみられる。

This is the largest leak from the circulatory water injection and cooling system since the system started [in June]. The density of radioactive cesium in the water is 45,000 becquerels/liter, 300 times the density allowed by law for the water to be released into the ocean. The density of radioactive strontium is not yet available, as it takes time to measure. But judging from the previous data, it is considered to be 100 million becquerels/liter, 1 million times the density allowed by law.


TEPCO has stopped the operation of the apparatus, but the injection of water into the reactors continue, as there are more than 10,000 tonnes of treated water in the storage tanks. TEPCO says, "It won't affect the cold shutdown."

 東電によると、4日午前11時半ごろ、下請け企業の作業員が、汚染水を淡水化する装置から水が漏れているのを見つけた。処理水が漏れ出て周囲に45トン たまり、たまった水が床近くのひび割れから外に出て側溝に流れ込んでいるのが確認された。水漏れは土嚢(どのう)でせき止めた。

According to TEPCO, a worker at an affiliated company [subcontractor] found the leak from the apparatus that desalinate the water at about 11:30AM on December 4. 45 tonnes of the treated water leaked from the apparatus, and the water was found leaking from cracks in the [concrete] near the floor into the side drains outside. The leaks were stopped by sandbags.

The worker who tweets from Fuku-I sort of confirms the story with his tweet on December 7:

"It looks like 220 tonnes, not 45 tonnes, that leaked.."

(H/T Lena for Asahi article)


Lena said...

Looks like there will be much more going into the Pacific from March if not earlier.

According to the Japan Times, Tepco´s decontamination system cannot handle strontium.

Anonymous said...

So one possibility is that up to 220 t of contaminated water have leaked from the system.
The information from the press conference seems to indicate that 45 t are still in the building. This would mean the remaining up to 175 t must have left the building.

Lets assume from these 175 t, only 150 t reached the ocean and the rest soaked into the ground. So in the press release, they correctly stated the amount of water inside the building with 45 t, but due to a simple 'mistake', they mixed up the 't' and 'l' of the second number - since they are so similar - and instead reported that 150 l reached the ocean.

If this hypothesis is right, this would mean that we have to add 3 more zeros to the number of radiation that leaked into the ocean, setting it to 26,000,000,000,000 becquerels (thats 'just 12,000% of the amount a nuke plant is allowed to leak per year).

I think a convenient and cost saving way to dispose of this highly contaminated water.

Anonymous said...

So If one tonne (1000 liters) is about 173 billion becquerels, and TEPCO has 10,000 tonnes in a storage tank, how do they expect to deal with this vast amount of dangerous materials?

Atomfritz said...

I think anonymous 4:06pm could be right; this wouldn't be the first time that Tepco made "mistakes" of this sort.

And anonymous 4:28pm points to the imho crucial point.

Letting the tanks get ripped open in the winter by freezing water could be an elegant way to get rid of that annoying and expensive waste water problem.

Tepco bosses in the TV would just say with a smile "Oops! We apologize!".

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