Treated water release deemed safe but local entities need convincing

By Makio Hattori and Ai Yamanami / Yomiuri Shimbun Staff Writers

18:22 JST, May 19, 2022

Nuclear regulators have endorsed a plan to release treated radioactive water stored at the crippled Fukushima No. 1 nuclear power plant into the sea, but convincing local authorities and other entities to support the plan remains the challenging next step.

The Nuclear Regulation Authority’s initial assessment report agreed Wednesday that plant operator Tokyo Electric Power Company Holdings, Inc.’s plan to discharge the treated water via a seafloor tunnel presented no safety problems, a decision that effectively meant the plan had passed the NRA’s assessment process. Attention will now focus on whether TEPCO and the central government can implement adequate measures to counter possible reputational damage to regional seafood and other industries due to the water’s release, as local consent is required for the plan to move ahead.

NRA Chairman Toyoshi Fuketa seemed acutely aware of this as he emphasized the planned release could be carried out safely.

“It’s scientifically unthinkable that there could be an impact on people’s health and marine products, but we very carefully examined the plan because many, many people are interested in and concerned about this issue,” Fuketa said at a press conference in Tokyo on Wednesday.

TEPCO applied for an evaluation of the discharge plan in December. The NRA held 13 review meetings through April that mainly assessed the technical aspects of the discharge facility’s safety, what steps would be taken in the event of a malfunction, and the impact discharging the treated water into the ocean would have on human health and the environment. During the assessment process, TEPCO was told to increase the number of flow meters installed to detect leaks of treated water, just in case these components break down. This addition increased the overall safety of the plan.

The nuclear watchdog will finalize its assessment report after a 30-day period during which the public can submit comments and opinions. The NRA then aims to approve the plan.

Millions of tons

TEPCO has started drilling and making other preparations for constructing the tunnel that will be vital for releasing the treated water offshore. However, approval from the Fukushima prefectural government and the local towns of Okuma and Futaba will be needed before construction can get into full swing.

Under the plan, the tunnel will be constructed to a spot about a kilometer out to sea from the nuclear plant, which suffered a triple meltdown from the March 11, 2011, earthquake and tsunami. Contaminated water at the plant that has had most radioactive materials except tritium removed will be released from the end of this tunnel. TEPCO will dilute the treated water with seawater so the tritium concentration is less than one-40th of the government-set safety standard before it is discharged. Construction of the tunnel, monitoring of the water in the area and other operations will cost about ¥43 billion, which will come from reserve funds allocated for decommissioning the plant’s reactors.

Tritium, an isotope of hydrogen, can be found in rainwater and tap water. Tritium can exist as part of a water molecule, so separating it from water is difficult. As tritium decays, it gives off beta radiation, but this radiation’s range is only about five millimeters in the air so it has minimal impact.

The operation of nuclear power plants and the collision of cosmic rays from space with molecules in the atmosphere are two sources of tritium. Discharging from nuclear plants water containing tritium, after it has been diluted to a concentration below set standards, into the ocean and rivers is an internationally accepted practice.

As of May 12, about 1.3 million tons of treated water was being stored in tanks on the nuclear plant’s grounds. TEPCO has said these tanks will reach full capacity in summer or autumn next year. Continuing to store such a massive volume of treated water would impede decommissioning work at the plant, so the government decided in April 2021 on a plan to start discharging water into the ocean from the spring of 2023. Releasing all the stored water is expected to take several decades to complete.

Room to improve

Unlike other radioactive materials, tritium can be handled safely by just diluting it with water. However, the Fukushima Prefectural Federation of Fisheries Cooperative Associations and other entities are concerned that dumping the water could harm the reputation of the area’s marine products and other goods. These groups have resolutely opposed any treated water discharge. In 2015 TEPCO promised the prefectural federation that it “will not dispose of treated water without the understanding of relevant entities.”

In November 2021, the Economy, Trade and Industry Ministry announced it would establish a ¥30 billion fund to support measures for alleviating reputational damage arising from the water discharge. For instance, if the price of marine products from the prefecture dropped because of harmful rumors about the treated water’s release, the fund would be used to buy up these products.

In a bid to ease the concerns of fishermen and fishery operators, TEPCO also is preparing to conduct a survey to determine whether flounder and abalone raised in treated water have any problems compared with those raised in regular seawater. The findings of this survey will be released to the public.

According to an online survey the Reconstruction Agency conducted in January, only 43.3% of respondents said they were aware of the plan to discharge treated water after it was significantly diluted into the sea. This finding revealed that the government and TEPCO have room to improve when it comes to disseminating information on this issue.

Construction delays

TEPCO has repeatedly pushed back the time frame for when it expects the storage tanks to reach full capacity. This date has changed from “around summer of 2022” to “autumn or later in 2022” to “spring of 2023” to, most recently, “summer or autumn of 2023.” Although this is the result of construction work that prevented rainwater from entering the reactor buildings and thereby generating less contaminated water, these shifting time frames also stir up distrust.

The nuclear plant covers an area of about 3.5 million square meters. According to TEPCO, most of the about 2.8 million square meters that is suitable for installing facilities has either already been built on or its usage has been decided.

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

A senior industry ministry official echoed this view.

“It’s not that there are no more usable sites left, but we can’t just keep building more and more facilities there forever,” the ministry official said.

In December, TEPCO announced a target date of June for starting full-fledged construction of the discharge facility. However, that schedule is already certain to be delayed. Completing the seafloor tunnel is expected to take about 10½ months, so it possibly will not be finished in time to start releasing water next spring as the government and TEPCO have hoped.

“A lot of work remains to be done, such as building a consensus with the local communities,” said University of Tokyo Associate Prof. Hiroshi Kainuma, a sociology expert. “The government should identify the causes of harmful rumors and take steps to counter reputational harm and devote more resources to sharing information, such as the results of the NRA’s latest evaluation of the discharge plan.”