Last week, a number of media outlets were reporting that nuclear regulatory authorities in Japan are considering the dumping of huge amounts of contaminated water containing the radioactive isotope tritium from the Fukushima site into the Pacific Ocean. This is due to the ongoing issue of ever increasing amounts of tanks containing such water on the Fukushima site and the lack of space to continue to build more. The stored water was used to cool down the stricken Fukushima reactors ever since the disaster took place over 5 years ago. (1)
The Nuclear Free Local Authorities (NFLA) is highly concerned about such a decision being made and the health, safety and environmental risks around potentially hundreds of thousands of tonnes of such water being dumped into the marine environment.
In a letter to the Guardian, the NFLA Chair wrote:
I read with concern your report on the possibility that very large volumes of water containing radioactive tritium arising from the Fukushima disaster could be dumped into the Pacific Ocean (Guardian, 13th April). The number of tanks is closer to 1,500 now: dumping such large amounts of highly radioactive water is a risk that needs to be very carefully considered and would be best avoided.
The Japanese nuclear industry and its regulators incorrectly suggest that tritium is relatively benign. They think that because it is similar to ordinary water, tritium won’t do much harm. But, as shown by UK Government reports and by independent experts on radioactivity, the reality is that this very similarity is part of the problem. Tritium is quickly absorbed by the body via inhalation or ingestion and easily enters cellular DNA. Moreover it combines with organic tissues and causes more damage than currently admitted.
Do we really want to be part of some enormous radiation experiment when there is so much uncertainty about the outcome? I suggest we do not”. (2)
NFLA asked a number of experts for their comments on the environmental risks of dumping tritiated water into the Pacific Ocean. In a detailed response, independent marine radioactivity consultant Tim Deere-Jones highlighted eight particular reasons for such concern, including:
- In the 1950s, when the discharge of liquid radioactive wastes to sea were first permitted, there was no knowledge of the way such levels of radioactivity would behave in marine and coastal environments and a very poor understanding of the marine parameters that govern the behaviour and fate of radioactivity in such environments.
- In the absence of any relevant empirical data, the IAEA and the nuclear industry hypothesised that liquid tritium (as tritiated water) is of low biological significance because it is a low activity beta emitter, which would dissolve into infinity once in the marine environment.
- The IAEA and the Japanese Nuclear Regulators commentary on tritium has not significantly changed since the 1950s.
- However the IAEA/nuclear industry claim, that tritium is of low radiological significance, is now shown to be highly questionable as neither body has adopted the outcomes of recent (post 1990’s) scientific studies which contradict almost every facet of the official position.
- Thus, there never has been a rigorous scientific justification, based on detailed empirical evidence, for the discharge to sea of tritiated water.
- The post 1990s research demonstrated that tritium in discharged tritiated water becomes bound to organic material in the organically-rich receiving marine environment. Organically bound tritium (OBT) is biologically available and highly mobile through the marine food webs. OBT is found to be highly bio-accumulated in species towards the top of the marine/coastal trophic level (such as in cod and shelducks). Such species typically hold concentrations between 2,000 to 6,000 times more enriched than the concentrations in the receiving waters. OBT is of far greater radiological significance than tritiated water. From this work it may be deduced that relatively elevated dietary doses of marine sourced tritium to humans (via sea foods) are strongly indicated.
- Other mechanisms for delivery of dietary doses of marine discharged tritium (as tritiated water and OBT) which include non-sea foods are also strongly indicated in the context of reported UK studies of the sea-to-land transfer of marine soluble and particle associated radioactivity. These studies demonstrate dietary doses from the consumption of beef and mutton, contaminated with radioactivity on coastal pasture washed by high tide, storm surge and coastal inundation. Marine radioactivity also transfers from the sea to the land in sea spray and marine aerosols derived from the surf line and breaking waves. Such material has been found at least 10 miles inland where it is identified on pasture grass and arable crops and entering the human food chain and thus generating a dietary dose of marine radioactivity in terrestrial produce.
- There is a major absence of data to support any claim that the tritium released to date has NOT given rise to doses to coastal populations. In such a context, the proposal to dispose of the very high volumes of stored tritiated water with its very high calculated aggregated radioactivity is strongly contra-indicated.
- This review concludes that the Fukushima event (downstream) coastal populations are those most likely to emerge as the marine/coastal Critical Population Group due to their exposure to dietary doses of tritium (mostly as OBT) from both sea foods and terrestrial produce. The Fukushima event Coastal Critical Population Group is also strongly indicated as the potential receiver of inhalation doses of airborne tritium (due to sea to land transfer processes).
- In the context of the emerging empirical evidence, and the significant data gaps described above, and the proposed release of over 800,000 tonnes of highly tritiated water (with an aggregated radioactivity (calculated at nearly 3 times the average annual discharge of tritiated water from the UK Sellafield reprocessor sea pipelines); it is concluded that the proposals lack both scientific rigour and justification; and are irresponsible in regard to the health of the coastal zone inhabitants of the Fukushima coast (downstream) and coastal zone and consumers of food stuffs produced in inshore waters, the intertidal zone and the terrestrial coastal zone for at least 10 miles inland. (3)
NFLA Chair Councillor Ernie Galsworthy said:
As my letter to the Guardian noted, NFLA is highly concerned over the health and environmental effects of dumping such large amounts of contaminated water from the Fukushima site into the Pacific Ocean. The additional information from independent experts only heightens our alarm. I reiterate my point that we should not be commencing an enormous radiation experiment when there is so much uncertainty about its outcome. I urge the Japanese authorities to think again and avoid such a practice.”
For more information contact the NFLA Secretariat on 07771 930196.
Notes for editors:(1) The Guardian, 13th April 2016 http://www.theguardian.com/environment/2016/apr/13/is-it-safe-to-dump-fukushima-waste-into-the-sea
(2) Copy of letter from the NFLA Chair to The Guardian, 14th April 2016
(3) Report provided to the NFLA by Tim Deere-Jones. The full report is being developed into a NFLA Radioactive Waste Policy Briefing which will be placed shortly on the NFLA website http://www.nuclearpolicy.info.