Disclosure of rearing condition
The status of Marine Organisms Rearing Tests is widely disseminated in a timely manner through rearing log entries, monthly reports and live stream videos, etc.
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You can see the rearing condition in real time
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Click here for daily rearing condition (on web page only in Japanese)
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Click here for daily rearing condition (on X only in Japanese)
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Click here for the rearing test monthly report (only in Japanese)
Purpose
We will demonstrate that the water to be discharged is safe “in a visible manner”.
In conjunction with the ALPS treated water discharge into the sea, marine organisms rearing tests are being implemented to show “in a visible manner”, thereby demonstrate that the water to be discharged is safe.
Results of rearing condition
Results and insights of tritium concentrations in flounder body
Free water tritium (FWT): Tritium that exists in the form of water in living bodies
Organically bound tritium (OBT): Tritium that is organically bound with carbon and other molecules in living bodies
- In graphing the measurement results, points below the detection limit and suspected adulteration were removed.
- Similar analysis results have been reported in the following literature in the past.
FY 2009 Experimental Study on Carbon Transfer in Land and Aquatic Ecosystems, Research Institute of Environmental Science and Technology
【Overview of the video】
- The tritium concentration in flounder body does not exceed the concentration of seawater containing ALPS treated water in which they are grown.
【Tritium intake test】 - The tritium concentration is maintained at the same level as the seawater in the growing environment after a certain period of time.
【Tritium intake test】 - The tritium concentration in flounder body quickly decreases as time passes when they are returned to normal seawater.
【Tritium discharge test】
- The results for abalone and seaweed were consistent with the results for flounder. The OBT concentration test for flounder is currently being conducted.
Overview of rearing test
Rearing tests will be conducted in both “seawater” and “ALPS treated water diluted with seawater” and the growth of the organisms in their respective environments will be compared against each other. We will confirm that "when marine organisms are reared in ALPS treated water that has been diluted with seawater, the tritium concentration in a living body reaches an equilibrium after a certain period of time," and "the concentration of tritium in the bodies of reared marine life does not exceed that of the environment which it was reared in."
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Flounder, abalone and seaweed that inhabit off the coast of Fukushima Prefecture have been selected for rearing.
Organisms to be reared [Before the start of discharging ALPS treated water into the sea]
- Fish
- Flounder (young fish) - around 800 flounders
- Shell
fish - Abalone (young shellfish) - around 800 abalones
- Sea
weed - Sargassum (seaweed) - around several kg
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Rearing in a closed circulation system* with careful handling of radioactive materials.
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Measure and assess tritium concentration, etc. in all rearing organisms.
Environment set in rearing test
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Normal
sea
water Normal seawater [Taken from around the power station]
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Condi
tion1 ALPS treated water diluted with seawater [Tritium concentration: Less than 1500 Bq/L]The tritium concentration of water used for rearing purposes has been adjusted to be less than 1,500Bq in consideration of the Japanese Government's Basic Policy on the discharge of ALPS treated water that stipulates that tritium concentration must be less than 1,500Bq/L.
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Condi
tion2 ALPS treated water diluted with seawater [Tritium concentration: approx. 30Bq/L]Considering the result of dispersion simulation that the tritium concentration around the discharge tunnel outlet is approx. 30Bq/L, the tritium concentration in Condition 2 is adjusted to approx. 30Bq/L.
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Refere
nce Water discharged into the environment [Tritium concentration: Less than 1,500Bq/L]After the start of discharge into the sea, rearing tests will be conducted also in the water that has been discharged into the environment (Tritium concentration: Less than 1,500Bq/L).
Rearing test status
Achievement so far
Prior to commencing Marine Organisms Rearing Tests, the process was examined for more than six months after which rearing tests began on September 30, 2022.
2022
March 17
Start of rearing practice in normal seawater Click here for details
June 9
We found parasites in a fillet of weakened flounder Click here for details
After this, for preventing the spread of parasites, such as saltwater baths and the installation of UV disinfecting equipment, etc., were implemented.
September
13
Start of rearing in rearing test tanks for getting flounder used to the environment Click here for details
Brought new 800 flounders to rearing practice tanks
September
30
Start of flounder rearing test Click here for details
October
3
Added the ALPS treated water to the rearing mockup tanks Click here for details
October
25
December
26
Published the results of intake and discharge tests of tritium (Free water tritium [hereinafter referred to as "FWT"]) in flounder body fluid in "Marine Organisms Rearing Log" Click here for details
2023
May
1
Published the results of intake and discharge tests of FWT in abalones in "Marine Organisms Rearing Log" Click here for details
May
9
May
10
Check the growth conditions of flounders and abalones by a Marine Organisms professional Click here for details
May
31
Published the results of intake and discharge tests of FWT in seaweed in "Marine Organisms Rearing Log" Click here for details
December
11
Published the results of intake tests of tritium (Organically bound tritium [hereinafter referred to as "OBT"]) in flounder muscle in "Marine Organisms Rearing Log" Click here for details
2024
January
10
October
15
Rearing of flounders and abalones begins using water that was discharged into the environment Click here for details
