Many tanks sit at the site of the Fukushima Daiichi Nuclear Power Plant, filled with water that has been processed by the so-called Advanced Liquid Processing System (ALPS, also described as a multi-nuclide removal system). The system treats a mix of cooling water from fuel debris as well as groundwater that has flowed into the reactor and turbine structures. At the time of writing, already more than a million cubic meters of treated water were being stored in about 1,000 tanks.
The Ministry of Economy, Trade and Industry (METI) held briefings and public hearings on the disposal of ALPS treated water on August 30 and 31, 2018, in Tomioka and Koriyama (both in Fukushima) and Tokyo. Documents distributed there stated that the tanks contained 1,000 trillion Bq of tritium. METI claimed that most radioactive substances other than tritium had been removed from the water, and presented five proposals to dispose of it. One proposal was to release it into the sea. The documents claimed that tritium only emits weak radiation, exists in nature, does not bio-concentrate, and is emitted from nuclear power plants all over the world.
Water in most tanks contains radioactive substances other than tritium
Prior to the public hearings, Kyodo News broke the story that nuclides other than tritium were detected in the treated water at concentrations that exceeded regulated standards.1 More media outlets then covered the story. With regard to iodine-129, as far as FoE Japan was able to confirm from data disclosed on TEPCO’s website that concentrations exceeded standards in 65 out of 143 samples between April 2017 and July 2018. At the public hearing the documents used at that time presented old data for the period September 20 to 28, 2014, when standards were not being exceeded. However, TEPCO announced after the public hearings that 85% of the tank water exceeded standards.2
Fig. I- 129 concentration at the exits of the ALPS
42 of 44 speakers opposed discharge to the sea
At the hearings held at three venues, 42 out of 44 speakers stated clearly that they opposed ocean discharge. Most poignantly, speakers from the fishing industry, including Tetsu Nozaki, head of the Fukushima Prefectural Federation of Fisheries Co-operative Associations spoke about the devastating impacts the marine discharge would have on the fisheries which had been revived so painstakingly. Many speakers pointed out the dangers of tritium and said it should be stored in tanks long term. Here are key issues raised at the hearings:
- The government should consider proposals for long-term storage in large tanks.
- There has been a failure to consider total discharge volume controls and cumulative impacts.
- The annual control target value for tritium discharge before the Fukushima Daiichi accident was 22 trillion Bq, but the ocean release proposal surpasses that amount.
- The risks (bioaccumulation, internal exposure, uptake into DNA) of organically bound tritium have not been sufficiently studied and explained
- This will become an international issue. It may be in conflict with the intent of the London Convention (Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter 1972).
After the hearing, Mr. Yamamoto, chair of METI’s treated water subcommittee, stated that they would add “tank storage” as an alternative plan. People are watching closely to see what happens next.
- Kyodo News, August 19, 2018, “Radioactive substances other than tritium detected at above regulated levels in Fukushima, including nuclides with long half-life” (in Japanese).
- According to Document 3 of the Subcommittee on handling of treated water including from multi- nuclide removal equipment (10th meeting, 3-Oct-2018), for the total of 62 nuclides, 85% of the water exceeded standards.