Saturday, May 24, 2014

Tritium in Seawater Over 30 Years in Japan

TEPCO has started the groundwater bypass operation, releasing the groundwater drawn before it reaches the highly contaminated reactor buildings in Fukushima I Nuclear Power Plant. Fukushima Minpo (5/24/2014) has the information on nuclide analysis of the seawater after the release:


TEPCO released the nuclide analysis of seawater before and after the release of groundwater from "the groundwater bypass" scheme on May 23, 2014. No significant change was observed.


According to TEPCO, the seawater sample was taken about 220 meter south of the groundwater bypass drainage outlet and analyzed. Cesium-134 and cesium-137 were below detection levels before and after the release of the groundwater. All-beta was 12 Bq/L before the release, and 11 Bq/L after the release.


Tritium was 3.9 Bq/L before the release, and 2.2 Bq/L after the release.

Tritium in single-digit becquerels per liter of seawater. How does this compare to what existed before the Fukushima nuclear accident?

From the database maintained by Japan Chemical Analysis Center (radiation monitoring around nuclear facilities in Japan), the historical range for Fukushima Prefecture from 1979 to 2010 (two nuclear power plants - Fukushima I and Fukushima II) is approximately 0.4 Bq/L to 4 Bq/L.

How does Fukushima compare to other prefectures with nuclear power plant?

Here's a chart plotting tritium levels in Fukushima (two plants with 8 boiling water reactors), Ibaraki (2 plants, one decomissioned, one boiling water reactor from 1978 on), and Hokkaido (one plant with 3 pressurized water reactors, from 1989 on).

Now Fukushima is in red triangles (which I have no control over in the chart creation app at the website), Hokkaido in blue squares, and Ibaraki in black crosses. The range is approximately 0.4 Bq/L to 200 Bq/L (Ibaraki).

Hokkaido's spike above 10 Bq/L in 2011 may be the effect from the Fukushima nuclear accident, but the sample was collected in August 2011, nearly five months after the start of the accident and four months after the leak of extremely contaminated water from Reactor 2.

Now let's add "Nuclear Ginza" - Fukui Prefecture, with 13 reactors (most of which are pressurized water reactors). The range is approximately 0.4 Bq/L to 1100 Bq/L (Fukui).

1100 Bq/L of tritium was measured from the sample taken off Tateishi on April 24, 2009, according to the Japan Chemical Analysis Center database. Tsuruga Nuclear Power Plant is located nearby. I couldn't find any incident on or around that date for the plant.

Finally, a chart that includes all prefectures with tritium measurement:

I am trying to find the data on tritium levels in seawater off Fukushima AFTER the accident, but it's not in the Japan Chemical Analysis Center database. The prospect of shifting through the government data on ever-changing links is not very appealing...


Anonymous said...

There appear to be no historic levels measured for Strontium, Cesium, or any of the hundreds of other radionuclides produced by nuclear fission.

I wonder why?

Anonymous said...

They have released the ground water analysis a couple of months back which has strangely disappeared, think it was something daft like 400,000/L
And it looks like they are finally taking note if what I put in twitter a couple of months back about monitoring tritium levels in preparation for what might hit the US northern sea boards, and have cooked the books again!

TEPCO I am a trained NARO specialist my job use to be to contain and control the clean up of messes like this,
The world is watching you, you start lying to me and the rest of the world and I will shame you to the world.

Anonymous said...

The previous measurements of groundwater are still up on the Tepco site. Total beta sources were measured at over 900k in one location. They are taking measurements at a number of locations, and the location mentioned in the story today is different from where the high measurements were taken in October.

Anonymous said...

Tsuruga is where? at the tip of the peninsula or deeper in the bay? At that level of activity there's no anomalies in ocean life?

"1100 Bq/L of tritium was measured from .. Tateishi. Tsuruga Nuclear Power Plant is located nearby."

arevamirpal::laprimavera said...

Location of Tateishi on google map:

It looks like either a one-off event, data transcription error, or measurement error.

Legal limit for tritium in water released from Fukushima I is 60000Bq/L. Tsuruga has a boiling water reactor and a pressurized water reactor, so the limit may be higher. (PWR releases more tritium.) The limit is for the exhaust water from the plant, not for the seawater.

Anonymous said...

I'd found Tateishi on google but was wondering where Tsuruga itself is.

1100 Bq/L must be like mouthwashing with hydrogen peroxide solution?

Anonymous said...

Don't be silly. Canada's limit for tritium in drinking water is 7000 bq/l. Australia's limit is 76,000 bq/l. The World Health Organization suggests a limit of 10,000 bq/l.

Hate to use the cliche "Google is your friend"... but sometimes its true.

Anonymous said...

Can you publish similar charts for Strontium-90? Particularly the 2011-2014 readings - thanks!

Anonymous said...

Anon at 8:07PM, do it yourself.

Anonymous said...

Anonymous said...

"Hate to use the cliche "Google is your friend [,absurd, and incomplete]"... but sometimes its true."

fixed it for 'ya

In this later days of post-industrial apocalypse, search engines like googlemaps, when queried for Tsuruga do not tell you where it is .. because it's important to assist information control like the fantasy that creatures that take their oxygen from the waters they swim in are unaffected by internal doses of that much tritium.

Anonymous said...

Abe maneuvering for restarts

Anonymous said...

@6:34 Agreed: even the staunchly pro-nuke Nikkei newspaper admits that two members of the "cautious" faction of the NRA have been replaced and that electric utilities expect progress towards the restarts (電力各社、再稼働審査の前進に期待 規制委慎重派ら2人交代へ)

According to the same newspaper the Abe government strongly wanted the two "cautious" commissioners to be replaced (菅義偉官房長官は27日の記者会見で [...] 島崎、大島両委員の交代については「(両委員は)今期限りの退任の意向が強かった」と説明した。「官邸の意向だ」。)

Commissioner Shimazaki (an earthquake scientist) assessed a few npps to be on top of active faults therefore their review stalled. According to a member of the Parliament that belongs to the pro-restarts LDP the replacement of commissioner Shimazaki is tailwind in favour of the restarts.
(地震学者の島崎邦彦 [...] 島崎委員は活断層を厳しく評価し、いくつかの原発で再稼働に向けた審査が止まっている。再稼働推進派の自民党の議員も「島崎さんの交代で、再稼働に追い風が吹く」と語る。)

Anonymous said...

Workers fleeing the sinking Fukushima Daichi (it is not just the Korean sailors, apparently), inability to operate important safety equipment like the isolation condenser, attempts to salvage reactors that led to a delay in their cooling and more at

Tepco should never have been entrusted the operation of nuclear powerplants.


Anonymous said...

"Tepco should never have been entrusted the operation of nuclear powerplants."

That became obvious after the big quake on the west coast of Japan.

Then the Japanese govt. chose not to seize the company after Fuku.
The Japanese govt. should never have been entrusted with the nation's welfare.

An island nation ringed with defective nuclear plants.

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