The release of treated radioactive water is considered safe, but local authorities need convincing

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May 20, 2022

TOKYO – Nuclear regulators have approved a plan to release treated radioactive water into the sea from the shut down Fukushima No. 1 nuclear power plant, but convincing local authorities and others to support the plan remains the difficult next step.

The Nuclear Regulation Authority’s first assessment report on Wednesday agreed that plant operator Tokyo Electric Power Company Holdings, Inc.’s plan to divert the treated water via a seabed tunnel presented no safety issues, a decision that effectively meant the plan abandoned the assessment process the NRA had passed . Attention will now focus on whether TEPCO and the central government can take appropriate action to counter potential reputational damage to regional fish and other industries due to the release of the water, as local approval is required to move forward with the plan.

NRA chairman Toyoshi Fuketa seemed well aware of this, stressing that the planned release could safely go ahead.

“It is scientifically unthinkable that there could be any impact on the health of people and marine products, but we have considered the plan very carefully because many, many people are interested and concerned about this issue,” Fuketa said at a news conference in Tokyo.

TEPCO requested an assessment of the relief plan in December. The NRA held 13 review meetings through April, mainly assessing the technical aspects of the safety of the discharge facility, the actions to be taken in the event of a malfunction, and the impact on human health and the environment of the discharge of the treated water into the ocean. During the evaluation process, TEPCO was instructed to increase the number of flow meters installed to detect leaks in treated water, just in case those components fail. This addition increased the overall security of the plan.

The nuclear watchdog will complete its assessment report after a period of 30 days for the public to comment and provide opinions. The NRA then intends to approve the plan.

million tons
TEPCO has begun drilling and other preparations for the construction of the tunnel, which will be critical to the offshore discharge of the treated water. However, the approval of the Fukushima prefectural government and the local cities of Okuma and Futaba is required before construction can go ahead.

According to the plan, the tunnel will be built at a location about one kilometer away from the nuclear power plant that suffered a triple meltdown in the March 11, 2011 earthquake and tsunami. At the end of this tunnel, contaminated water is released into the facility from which most radioactive materials except tritium have been removed. TEPCO dilutes the treated water with seawater so that the tritium concentration is less than one-40th of the government’s safety standard before it is discharged. Building the tunnel, monitoring water in the area and other operations will cost about 43 billion yen, which will come from reserve funds allocated to decommission the plant’s reactors.

Tritium, an isotope of hydrogen, is found in rainwater and tap water. Tritium can exist as part of a water molecule, so it’s difficult to separate from water. When tritium decays, it emits beta radiation, but the range of this radiation is only about five millimeters in air, so it has minimal effect.

The operation of nuclear power plants and the collision of cosmic rays from outer space with molecules in the atmosphere are two sources of tritium. The discharge of tritiated water from nuclear power plants, after it has been diluted below established standards, into oceans and rivers is an internationally recognized practice.

As of May 12, about 1.3 million tons of treated water were stored in tanks at the nuclear power plant site. According to TEPCO, these tanks will reach their full capacity in the summer or fall of next year. Continued storage of such a large volume of treated water would hamper decommissioning work at the facility, so in April 2021 the government approved a plan to start discharging water into the ocean from spring 2023. It is expected that the release of all stored water will take several decades to complete.

room for improvement
Unlike other radioactive materials, tritium can be safely handled simply by diluting it with water. However, the Fukushima Prefectural Fisheries Co-operative Association and other organizations fear the release of the water could damage the reputation of the region’s seafood and other commodities. These groups have spoken out strongly against the discharge of treated water. In 2015, TEPCO promised the prefectural association that it “will not dispose of treated water without the understanding of the relevant bodies.”

In November 2021, the Ministry of Economy, Trade and Industry announced it would set up a 30 billion yen fund to support measures to alleviate reputational damage from the water discharge. For example, if the price of the prefecture’s sea products fell due to harmful rumors of the treated water release, the fund would be used to buy up those products.

Also, to allay the concerns of fishermen and fishery operators, TEPCO is preparing to conduct a survey to determine whether flounder and abalone farmed in treated water have any problems compared to those farmed in regular seawater. The results of this survey will be made available to the public.

According to an online poll by the Reconstruction Agency conducted in January, only 43.3% of respondents said they were aware of the plan to divert treated water after it was significantly diluted into the sea. This result showed that the government and TEPCO still have room for improvement in disseminating information on this topic.

construction delays
TEPCO has repeatedly pushed back the timeframe for the storage tanks to reach full capacity. This date has changed from “around summer 2022” to “fall or later in 2022” to “spring 2023” and most recently to “summer or fall 2023”. Although this is the result of construction work that prevented rainwater from entering the reactor buildings, thereby creating less polluted water, these timing shifts also fuel suspicion.

The nuclear power plant covers an area of ​​around 3.5 million square meters. According to TEPCO, most of the approximately 2.8 million square meters that are suitable for the installation of systems are either already built on or a decision has been made about their use.

“Installing even more tanks will be extremely difficult,” a TEPCO official told The Yomiuri Shimbun.

A senior official at the Ministry of Industry shared this view.

“It’s not that there aren’t any more usable sites, but we can’t keep building more and more facilities there forever,” the ministry official said.

In December, TEPCO announced June as the target date to begin full construction of the unloading facility. However, this schedule is already being delayed. The seabed tunnel is expected to take around 10½ months to complete, so it may not be completed in time for water delivery to begin next spring, as the government and TEPCO had hoped.

“There is still much work to be done, such as building consensus with local communities,” said sociology expert Prof. Hiroshi Kainuma of the University of Tokyo. “The government should identify the causes of harmful rumors and take measures to counteract reputational damage, and allocate more resources for information sharing, such as B. the results of the NRA’s most recent assessment of the redundancy plan.”

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