Ⅰ-2. Clarifying behaviors for radioactive substances in multimedia (atmosphere, soil, water, plants, organisms and ecosystems, etc.)
1. Atmospheric simulation for radioactive substances released from the Fukushima No.1 Nuclear Power Plant
A research group at NIES carried out a simulation using an atmospheric simulation model for the central region of Japan, in order to clarify the behavior in the atmosphere of radioactive substances released from the Tokyo Electric Power Company (TEPCO) Fukushima No.1 Nuclear Power Plant in the accident which accompanied the Great East Japan Earthquake of March 11, 2011.
One outcome of this simulation was evidence of the influence of radioactive substances as extending to an area beyond Fukushima Prefecture which included Miyagi, Yamagata, Iwate, Tokyo and six prefectures in the Kanto Region, Shizuoka, Nagano, and Niigata prefectures, among others.
Moreover, it was estimated from an analysis of the model that 13% of the Iodine 131 and 22% of the Cesium 137 released from the Fukushima No.1 Nuclear Power Plant was deposited on the Japanese mainland, with the rest deposited at sea or transported to territories outside the model domain.
These results where published in the August 11, 2011 electronic edition of Geophysical Research Letters, the official publication for members of the American Geophysical Union (AGU).
Below are relevant reference materials.
28th General Meeting, Power Plant Accident Impact Measures Project Team, Democratic Party of Japan (August 28, 2011)
· Iodine 131 (radioiodine) and Cesium 137 atmospheric concentration near surface, atmospheric deposition, accumulated deposition (March 12-23, 2011)
Click below images for video
The June 21, 2011 Ministry of Health, Labor and Welfare’s draft document “Interim report on measures for radioactive substances in tap water”, made use of the research outcomes of an atmospheric simulation model created under Director Toshimasa OHARA at the Center for Regional Environmental Studies.
This document took the form of an interim report aimed at safeguarding drinking water in the medium to long term in the wake of the accident at the TEPCO Fukushima No.1 Nuclear Power Plant. Based on an investigation of the impact mechanism of radioactive substances on drinking water, it proposed measures to deal with radioactive substances and summarized monitoring outcomes towards the definition of the future issues which this could entail.
In order to understand the mechanism of the issue of radioactive substances detected in the tap water in Fukushima Prefecture, the Kanto Region, etc. it is necessary to assess the advection and diffusion of radioactive substances in precipitation. Simulation outcomes from Director OHARA’s group were used towards the achievement of this end.
For more details see the pages below
3. Establishing the actual conditions and clarifying behaviors of radioactive substances in multimedia environments
NIES is implementing research relating to the establishment of the actual circumstances and clarifying the behavior of radioactive substances in multimedia environments by means of consignment studies commissioned by Ministry of the Environment, etc.
In order to understand the behavior of radioactive substances in multimedia environments in the atmosphere, on land and in coastal regions, we constructed a multimedia environments simulation model, utilizing measurement data for wide-area environmental dynamics for verification and research.
Moreover, as part of this research we continue to implement surveys on the release status for radioactive substances from forests on Mt. Tsukuba. We verified that the emission levels of radioactive cesium for one year after the accident were 0.3% of the initial accumulative dose.
This outcome was conveyed to the Environmental Remediation Committee of the Ministry of the Environment, and used in the September 2012 summary “Immediate preparatory measures for the forthcoming circumstances of forest decontamination”.
- Great East Japan Earthquake Information Page
- Ⅰ-1．Appropriate treatment and disposal of disaster waste and waste contaminated by radioactive substance
- Ⅰ-2. Clarifying behaviors for radioactive substances in multimedia (atmosphere, soil, water, plants, organisms and ecosystems, etc.)
- Ⅰ-3. Studies and projections on environmental change originating from the disaster and associated effects
- Ⅰ-4. Details of research outcomes presented at the NIES Public Symposium
- Ⅰ-5. An Overview of Research on Disaster Environment
- Ⅰ-6. (1) Tsukuba City radioactive substances and radiation measurements
- Ⅰ-6. (2) Research outcomes etc., from NIES researchers (Presented prior to the occurrence of the Great East Japan Earthquake)
- Ⅰ-6. (3) Kankyo Tenbodai (Environmental Observatory), search service for disaster information relating to environment in environmental information media
- Ⅱ. Information Sources Related to the Disaster
- An Overview of Research on Disaster Environment