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TEPCO overstates safety of treated water with dosimeter that cannot detect tritium during inspection tour of Fukushima Daiichi Nuclear Power Plant

October 3, 2022
The treated water is highly contaminated water from the cooling of nuclear fuel melted down in the reactor that has been decontaminated at least twice to basically contain only tritium, which emits weak beta radiation. Tritium cannot be removed even by decontamination equipment.
　During the inspection tour, a dosimeter that detects only gamma rays was applied to a bottle containing treated water, which contains about 15 times the standard level of tritium for release, to show that there was no reaction. According to TEPCO, it has been shown to about 1,300 groups and 15,000 people since July 2020. This paper received an explanation during an interview on March 14, 2008.
　The person in charge explained that, among the radioactive materials contained in the highly contaminated water in the buildings, cesium and other materials that emit gamma rays have been removed, and that the treated water is equivalent to the radiation level of the surrounding area. However, as long as they did not use a measuring instrument for beta radiation, it can only be said that “cesium is not contained in high enough concentration to react with dosimeters.
　Tetsuji Imanaka, a former researcher at the Compound Nuclear Science Institute of Kyoto University, said, “The energy of tritium is weak. Even if you soak tritium in filter paper and apply a beta-ray detector to it, it will not react unless the concentration is much higher,” said Tetsuji Imanaka, a former researcher at the Kyoto Combined Research Institute for Nuclear Science. Katsumi Azukawa, assistant professor of environmental analytical chemistry in the graduate school of the University of Tokyo, said, “Scientifically, it is completely meaningless. Gamma rays of cesium must be several thousand becquerels per liter for the dosimeter to react. Even if the cesium content is several dozen times the emission standard (90 becquerels per liter), it still gives the impression that there is no cesium.
　TEPCO told us, “The purpose of the demonstration is to explain that gamma rays that affect the human body due to external exposure have been reduced. The demonstration also explains that tritium, which emits beta rays, exceeds the emission threshold. As for how the demonstration should be, he only stated, “We will work on it while devising various ways.

◆Commentary: Are they really willing to gain understanding of treated water?
　TEPCO used a dosimeter that cannot detect tritium, a radioactive substance, in a demonstration to promote the safety of treated water at the Fukushima Daiichi Nuclear Power Plant. TEPCO had previously caused problems by giving unscientific demonstrations for the mass media. TEPCO’s attitude of continuing to show the same demonstration to many observers makes one wonder if they are really interested in gaining understanding of treated water.
As experts have pointed out, TEPCO’s demonstration does not provide any verification of beta or gamma radiation. To confirm this, the reporter applied a dosimeter of the same model as that used in the demonstration to water containing about 19 times the level of radioactive cesium that is the standard for emissions, but there was no reaction.
　Nevertheless, if the safety of the treated water was emphasized in this manner, it could be perceived as “manipulation of impressions” or “lies. A woman from Minamisoma City, Fukushima Prefecture, who was shown the demonstration during a recent public inspection tour, told this newspaper, “My distrust of TEPCO has grown stronger again.
　TEPCO has made efforts to reduce the risk of contaminated water at the Fukushima Daiichi Nuclear Power Plant by building durable welded tanks to prevent a recurrence of leakage accidents and by storing water using current technology. The shortest way to gain the public’s understanding of the treated water is to show that they are continuing their efforts in an honest manner at the site. (Takeshi Yamakawa)
https://www.tokyo-np.co.jp/article/206024?fbclid=IwAR2ZO9iKCa2vg_g9UCQSaPawnq9P_pZsnt6pOCuM–Bh7qMbD_rl_OqwFNk

October 8, 2022 - Posted by dunrenard | Fuk 2022 | Fukushima Daiichi, Radioactive Water, Tritium