Briefing paper: July 2018
Tim Deere-Jones (Marine Radioactivity Research & Consultancy: Wales: UK)
The problem of accumulating tritiated water at the Fukushima site continues to grow, as cooling waters are still being continuously applied at the site. There is increased pressure from TEPCO, regional Japanese agencies and international bodies to discharge the accumulated water into the sea. This pressure is supported by various “nuclear” agencies, both Japanese and International (including the IAEA) who continue to maintain that tritiated water discharged to sea is of no, or little radiological health consequence to the environment, marine workers (fishers, aquaculturalists etc) or coastal and coastal zone populations. This understanding of the impact of tritiated water discharges is based on an utterly discredited nuclear industry hypothesis for the behaviour and fate of radioactivity, and some very poor and now outmoded scientific research. The most recent (post 1990) UK research on the fate and behaviour of tritium (discharged as tritiated water) in marine, coastal and estuarine environments now clearly demonstrates that tritium has a significant potential for delivering high doses (both dietary and inhalation) to seafood consumers and coastal zone populations living up to 10 miles inland. This is an issue of the highest relevance to marine stakeholders and coastal zone populations along the east coast of Japan (Honshu). Attempts to belittle the impact of the proposed release to sea of millions of gallons of highly tritiated water, either in pulses or at slow release rates, are without scientific basis, irresponsible and potentially detrimental to human health.
6:6 Thus, populations living in the terrestrial coastal zone may be exposed to sea to land transferred radioactivity via a number of pathways. Flooding of a Welsh coastal town was shown to have transported hundreds of tons of marine sediment contaminated with elevated concentrations of Am 241 into private, commercial and public spaces and to have provided the potential for inhalation and contact doses during clean up and possibly for some time after. 6:7 In Wales, airborne radioactivity transferred from the marine environment in spray and aerosols has been observed in coastal produce grown at least 10 miles inland. At a number of other UK sites, distant from source points of marine radioactivity, contamination derived from sea to land transfer, and consumed in terrestrial foods, has been shown to generate higher doses than those received by seafood eaters close to point sources. 6:8 As described above, exposure of populations living in areas (up to at least 10 miles inland: possibly more) to inhalation doses is also strongly indicated along the Fukushima event downstream coasts. Thus 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. This 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)