Trust, but verify

Shim Hyung-jin

The author is a professor of nuclear engineering at Seoul National University.

Concerns are growing after the Japanese government announced that it could discharge contaminated water from the crippled Fukushima nuclear plant. As a result of the recent Korea-Japan summit in Seoul, a Korean inspection team consisting of experts and others will visit Fukushima for three nights and four days from May 23.

At the nuclear plant, radioactive water from reactors, groundwater inflow and precipitation has been stored in more than 1,000 large tanks after it was purified by a facility called the ALPS. As these tanks are full, Japan wants to dilute the stored water and release it into the sea. The ALPS removes most of the radioactive isotopes. The Japanese government plans to dilute tritium — which cannot be removed by ALPS — to 1,500 becquerels per liter (Bq/L), which is less than 1/40 of the emission standard, and release it into the sea.

How dangerous is this radiation? As people are unfamiliar with the unit of radioactivity, I will make a simple comparison for better understanding. In the Earth’s atmosphere, tritium is created by the reactions of neutrons generated by cosmic radiation and nitrogen and deuterium in the atmosphere. Tritium, which exists in the form of water, becomes rain and moves to the surface. In Korea, the tritium content of rainwater is measured for groundwater research. Its radioactive level is 0.118 Bq/L. When this value is multiplied by the annual precipitation of Korea and the land area, the radioactivity of tritium that falls by rain or snow for a year is 0.121 petabecquerel.

In other words, the radioactivity of tritium released into the Pacific from Fukushima’s stored water annually is about one-fifth of that in Korea’s rainwater. One thing I want to add is that the tritium concentration in drinking water recommended by the World Health Organization (WHO) is less than 10,000 Bq/L. Worrying about radiation exposure by rain is an ungrounded concern in the eyes of scientists.

According to a recent study jointly published by the Korea Atomic Energy Research Institute and the Korea Maritime Science and Technology Institute, the concentration of Fukushima discharge water entering Korean waters is about one millionth of one Bq/L. This is less than one billionth of the original concentration of discharged water, or 1,500 Bq/L. Compared to the concentration of tritium in rainwater, it is less than one 100,000th.

A media outlet claimed that it is difficult to predict the results because there is no precedent for discharging contaminated water from a nuclear accident into the sea. But there are similar precedents. Even now, the spent fuel reprocessing facility at La Hague, France releases tritium 450 times more than the level in the annual Fukushima discharge plan. Yet no notable environmental impacts have been reported.

If the plan announced by the Tokyo Electric Power Company is strictly followed, Fukushima’s storage water discharge is not a concern from a scientific perspective. But there is a Russian proverb that says, “Trust but verify.” The government should pay special attention to issues related to public safety.

Of course, independent verification of the process of discharging stored water is necessary, and the publicly acknowledged International Atomic Energy Agency is in charge of it. Korea is also participating in the IAEA’s task force team, while the Korea Institute of Nuclear Safety is analyzing samples of stored water as one of the related activities. Radioactive information on Fukushima’s stored water can be found on the IAEA website.

Except for recycling, the only way to dispose of radioactive materials is to reduce the amount to a minimum and then “manage” it at a special facility or “dilute” and discharge. Japan has chosen the method of dilution for the Fukushima storage water. In Korea, radioactive waste below the allowable concentration level can be incinerated, buried, and recycled.

Nevertheless, why do you feel uncomfortable looking at this problem? It is probably the ethical uncomfortableness from releasing man-made waste into nature. In other words, the issue of the Fukushima storage water discharge seems to be more of an ethical issue than a safety issue. The golden rule that determines whether an action is ethical or not is “Don’t do to others what you don’t want to be done by others.” The mindset can be applied to Japan and Korea alike. I am afraid that excessive anxiety far from scientific facts will make innocent fishermen suffer.

Translation by the Korea JoongAng Daily staff.