We as scientists do have a responsibility and I hope to be able to contribute in some way“
Ken Buesseler, researcher at the Wood Hoods Oceanographic Institute is investigating the radioactivity leaked from the Fukushima nuclear power station, initially from data facilitated by the TEPCO (Tokyo Electric Power Company) and then from samples gathered in situ. He believes that official bodies in Japan have not done enough to analyse and to take the situation in hand, and has thus called for the participation of independent experts.
As a consequence of the Fukushima disaster isotopes are reaching the sea and which are more radioactive than in Chernobyl. What sort of quantities are we talking about and what are the likely consequences?
While the total discharges at Fukushima may have been less than in Chernobyl, Fukushima is on the coast, and those great quantities of coolant water used have been directly discharged into the sea or have seeped through the ocean subsoil; and so 2-5 times more isotopes than at Chernobyl have been discharged into the sea around Fukushima.
At the beginning, in 2011, the concentrations in the ocean around the disaster area were very high. Then they dropped, only to rise again a few months later; pointing to ongoing leaks which still persist.
The impact of the radioactive isotopes is more worrying in the interior than at sea, as it bears directly on humans; in the ocean the isotopes are diluted rapidly and mix with the marine currents further from the coast. Nevertheless, the fact that isotopes such as caesium accumulate in fish is cause for concern for humans. This is why fishing grounds have had to be closed; there have been losses of millions of dollars and an important food resource lost from a local and cultural perspective.
How are the trends in radioactive isotopes in the sea being investigated? What techniques are being used?
We gather samples aboard the oceanographic vessel and take them to the laboratory. Then, we separate the natural isotopes from Fukushima and analyse them. For example, one of the most commonly used methods for analysing caesium isotopes is the measurement of gamma disintegration.
What are the principal conclusions of the research?
It is not enough to monitor the radioactive isotopes. We have to complete this with the knowledge of oceanographers. We have to know, for example, how marine currents influence the mixture of particles, and we can explain why the concentration of caesium is a thousand times greater in one place than in another, or how it accumulates in the trophic chain, or why a small part of the caesium ends up on the ocean bed and how long it will stay there.
In your view, what can Tepcok and the Japanese Government do to improve the situation? Do you think that others should be involved?
Yes, very much so: Japan should be inviting international experts to investigate the consequences borne by the oceans. Until recently they have not asked for help in the cleaning up tasks.
Participation by government agencies is not sufficient. In order to undertake an impartial study of the consequences, experts from Japan, the United States, Europe and other countries are needed and who are independent of nuclear energy and their sponsors.
More has to be undertaken than what has been done to date, in order to present the results to an ever more sceptical public.
What is the responsibility of a researcher like yourself? Can you or should you have influence on any concrete aspect? If so, on which and to what extent?
Yes, we as scientists do have a certain responsibility and I hope we can contribute in some way”. I have received many expressions of recognition of our work; for example, the special issue of the Oceanus journal and a FAQ page on the WHOI (the Woods Hole Oceanographic Institute) website, besides articles published in scientific journals.
What scenario is there in both the short and the long term?
My greatest concern is detaining leaks and spills from tanks and buildings, as well as putting effective systems for cleaning contamination into place. This is priority, and also guaranteeing the safety of the used fuel in the exterior tanks of the reactors. Unfortunately, there is currently more radioactivity in the tanks and fuel rods than there was in 2011, and so any quake or other accident now would be even more catastrophic than the initial event.
Ken Buesseler is a graduate in Biochemistry and Cell Biology and a PhD in Marine Chemistry. Currently, he is a Woods Hole Oceanographic Institute researcher, and he has specialised in investigating radioactive isotopes, on land and at sea. Prior to researching the radioactivity of the waters around Fukushima, he researched the remains of nuclear testing during the Cold War in the Atlantic Ocean, and also radioactive isotopes leaks from Chernobyl in the Black Sea.