Evaluation of Accumulated Fission Products in the Contaminated Water at the Fukushima Daiichi Nuclear Power Plant

2014 ◽  
Vol 188 (3) ◽  
pp. 252-265 ◽  
Author(s):  
Shunsuke Uchida ◽  
Masanori Naitoh ◽  
Hiroaki Suzuki ◽  
Hidetoshi Okada ◽  
Satoshi Konishi
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Fission Products ◽  
Contaminated Water ◽  
Fukushima Daiichi

Analysis of temporal variations of Cs-137 discharge inventory from the port of Fukushima Daiichi Nuclear Power Plant over 9 years after the accident

2020 ◽  
Author(s):  
Susumu Yamada ◽  
Masahiko Machida ◽  
Ayako Iwata ◽  
Shigeyoshi Otosaka ◽  
Takuya Kobayashi ◽  
...  
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Estimation Method ◽  
Coastal Region ◽  
Temporal Variations ◽  
Contaminated Water ◽  
Reactor Unit ◽  
Run Off ◽  
Fukushima Daiichi

<p>Just after Fukushima Daiichi Nuclear Power Plant (1F) accident occurred in March 2011, the direct discharges of highly-contaminated water from reactor Unit 2 and 3 into the 1F port followed. After the suppressions of the direct discharges, Kanda (Biogeosci. 10, 6107–6113, 2013) suggested that relatively small amounts of run-off of a radionuclide (Cs-137) from 1F port into Fukushima coastal region has continued based on his estimation method. However, Kanda’s estimation period was limited up to September 2012. Therefore, we expand the estimation period of the discharged inventory up to very recently, March 2020 with significant accuracy improvements by the present authors. As a result, we find that totally, in the period over 9 years, the discharged inventory has gradually diminished together with various characteristic fluctuations. In this presentation, we analyze the observed diminishing trends with temporal fluctuations and discuss their relationships with various suppression measures and constructions toward decommissioning of 1F. Furthermore, we estimate the annual discharged amount of Cs-137 and evaluate its impacts on the coastal area in terms of seawater concentrations.</p>

scholarly journals Impact on Fisheries in Contaminated Water Discharged from Nuclear Power and Reprocessing Plants: The Cases of La Hague Reprocessing Plant, Sellafield Nuclear Fuel Reprocessing Plant, and TEPCO Fukushima Daiichi Nuclear Power Plant

2021 ◽  
Vol 16 (5) ◽  
pp. 840-865
Author(s):  
Tetsuya Nakamura ◽  
Steven Lloyd ◽  
Atsushi Maruyama ◽  
Satoru Masuda ◽  
◽  
...  
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Local Governments ◽  
Nuclear Power ◽  
Central Government ◽  
Contaminated Water ◽  
Government Information ◽  
Nuclear Reprocessing ◽  
Fukushima Daiichi ◽  
Reprocessing Plant

This paper statistically analyzes residents’ understanding of problems related to radioactively contaminated water discharged from nuclear power and nuclear reprocessing plants. Moreover, this paper examines their impact on the surrounding fisheries by using the cases of La Hague, Sellafield, and Fukushima Daiichi Nuclear Power Plant. Survey data shows that more than 60% respondents disagree with the release of contaminated water, and this sentiment is particularly strong among both British and French respondents. Regarding seafood caught in the vicinity of the nuclear power and nuclear reprocessing plants, although British respondents noted that they hold it in high regard, many people do not purchase this seafood. In contrast, many Japanese respondents reported that they were less concerned, and thus, willingly purchase seafood caught off the coast of Fukushima Prefecture. In all three countries, many people did not trust government information on the release of contaminated water. Compensation to the affected people was provided by the central government, companies involved, and local governments, in that order. Japanese and British respondents reported higher expectation for compensation as compared to French respondents. Japanese and French respondents noted that they have knowledge of radioactive materials and contaminated water, and many of them purchased seafood caught in the vicinity of the nuclear power and reprocessing plants. British respondents were the most opposed to the release of contaminated water, whereas Japanese respondents were the least reliant on government information about the release of contaminated water. Finally, among those who trusted information from the government and retailers, French respondents were the least concerned about contamination. French respondents were also the least likely to expect any compensation for the fishermen affected by contamination. Both British and French residents around the affected plants expected the central government to compensate the affected fishermen, whereas those who did not reside around the affected plants did not expect the fishermen to be compensated. French respondents were more likely to expect compensation from the local governments; affluent respondents were more likely to expect the compensation to be funded by taxation, whereas less affluent respondents expected them to be funded by donations. Respondents who were more skeptical of government information wanted the companies involved to compensate the fishermen. British respondents reported a tendency for wanting the companies involved to provide this compensation, and did not support the concept of compensation provided through donations.

Fukushima Daiichi decontamination and decommissioning: current status and challenges

2021 ◽  
pp. 014664532110108
Author(s):  
Akira Ono
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Working Environment ◽  
Current Status ◽  
Contaminated Water ◽  
Spent Fuel ◽  
The Future ◽  
Fukushima Daiichi

It has been nearly 10 years since the accident at Fukushima Daiichi nuclear power plant. With the cooperation of those involved, the site, which was once in a crisis situation, has improved to the point where it is possible to look ahead and proceed with work on schedule. In the off-site area, conditions for returning home have been progressed, and evacuation orders for some areas have been lifted by the Japanese Government. This article describes, in respect of the various efforts being made on site at the moment, the current status of fuel removal from the spent fuel pools, preparations for fuel debris retrieval, improvement of the working environment, and future plans. Removal of fuel from the spent fuel pool for Unit 4 was completed in December 2014, and work is continuing with Unit 3 in order to complete by March 2021. The decision was made to install a large cover in advance for Unit 1 in consideration of the risk of dust scattering, and to conduct fuel removal for Unit 2 from the south side without dismantling the existing upper section of the building. The target is for fuel removal from the pools, including Units 5 and 6, to be complete by 2031. Regarding fuel debris retrieval, progress in various investigations has made it possible to grasp the distribution of debris in the reactor containment vessels of Units 1–3 to a certain extent, and it was decided that the first retrieval will start with the most-investigated unit (Unit 2). A robot arm will be used for retrieval; initially, a trial retrieval will be started, and once the retrieval method has been verified and confirmed, the scale of retrieval will be expanded in stages using a device with the same mechanism. The working environment of Fukushima Daiichi nuclear power plant has also improved. By reducing the stirring up of radioactive materials due to facing (paving), etc., it became possible to reduce the degree of protective clothing needed, and the area in which people can work with simple clothing such as general work clothes now represents 96% of the entire site. Due to various reduction measures, the effective dose of workers is currently approximately 0.2–0.4 mSv month−1 on average per person. The work environment will continue to be improved steadily in the future. Finally, I would like to briefly mention the direction of future decommissioning efforts. The decommissioning of Fukushima Daiichi nuclear power plant and contaminated water management are being implemented based on the national Mid-and-Long-Term Roadmap. The latest edition (5th revision) sets out the milestones until 2031, and we are on target to achieve the goals set forth here and the goals set forth in the Nuclear Regulatory Commission's risk map. To that end, the Mid-and-Long-Term Decommissioning Action Plan 2020, which shows the main work processes of the decommissioning, was announced. This will enable us to proceed with decommissioning work more systematically in the future while looking ahead. Local people who sometime are concerned about risk arising from Fukushima Daiichi may grasp the future work plan concretely in relief, and can consider taking part in the decommissioning work. The key lies in how we can contribute to the reconstruction of Fukushima through the decommissioning of Fukushima Daiichi nuclear power plant, and we will continue to take responsibility for decommissioning of the power plant and contaminated water management under the principle of ‘striking a balance of reconstruction and decommissioning’.

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