scholarly journals Time-Dependent Change of Ambient Radiation Dose Rate and Gamma-Ray Spectrum in Shinjuku, Tokyo, after the Fukushima Daiichi Nuclear Power Plant Accident

RADIOISOTOPES ◽  
2015 ◽  
Vol 64 (3) ◽  
pp. 185-195
Author(s):  
Hiroyuki KONISHI ◽  
Satoko FUJIE ◽  
Kiyomi IKUSHIMA ◽  
Mitsugu HOSAKA ◽  
Dai NAKAE
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Radiation Dose ◽  
Nuclear Power ◽  
Gamma Ray ◽  
Time Dependent ◽  
Radiation Dose Rate ◽  
Dependent Change ◽  
Time Dependent Change ◽  
Fukushima Daiichi

Model of a Dry Storage Facility for a Medium Nuclear Power Plant

2001 ◽  
Author(s):  
Mile Bace ◽  
Kresimir Trontl ◽  
Dubravko Pevec
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Radiation Dose ◽  
Dose Rate ◽  
Nuclear Power ◽  
Storage Facility ◽  
Spent Fuel ◽  
Radiation Dose Rate ◽  
Dry Storage ◽  
Fuel Assemblies

Abstract The intention was to model a dry storage facility that could satisfy the needs of a medium nuclear power plant similar to the NPP Krsko. The attention has been focused on radiation dose rate analyses and criticality calculations. Using the SCALE 4.4 code package and modified QAD-CGGP code, we modeled a facility that satisfies the basic criteria for public radiation protection. The capacity of the storage is 1,400 spent fuel assemblies which is adequate for a forty years medium NPP lifetime.

Investigation and Research on Depth Distribution in Soil of Radionuclides Released by the TEPCO Fukushima Dai-ichi Nuclear Power Plant Accident

2013 ◽  
Vol 1518 ◽  
pp. 277-282 ◽  
Author(s):  
Haruo SATO ◽  
Tadafumi NIIZATO ◽  
Kenji AMANO ◽  
Shingo TANAKA ◽  
Kazuhiro AOKI
Keyword(s):  
Surface Layer ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Radiation Dose ◽  
Nuclear Power ◽  
Depth Distribution ◽  
Distribution Coefficients ◽  
Radiation Dose Rate ◽  
Distribution Maps ◽  
Apparent Diffusion Coefficients

ABSTRACTThe accident of the TEPCO Fukushima Dai-ichi Nuclear Power Plant occurred by the 2011 off the Pacific coast of Tohoku Earthquake on 11 Mar. 2011. It is estimated that totally 1.2-1.5x1016 Bq for 137Cs and 1.5-1.6x1017 Bq for 131I were released until the beginning of Apr. and those radionuclides (RN) were deposited on soil surface and forest etc. widely around Fukushima Pref. This work was carried out as one of the investigations for making the distribution maps of radiation dose rate and soil contaminated by RNs which the MEXT promotes. The Geoslicer investigation on the depth distribution of RNs in soil was performed after 3 months from the accident. The investigation was conducted at 11 locations in Nihonmatsu City, Kawamata Town and Namie Town, and soil samples of depth 50 cm to 1 m were taken. Both of 134Cs and 137Cs were detected in all investigated locations, and 129mTe and 110mAg were detected only in locations where radiation dose rates are high. At many locations investigated, radiocaesium more than 99 % distributed within a depth of 10 cm in soil in the surface layer. On the other hand, RNs tended to distribute to deeper part in soil at locations that are supposed to have been used as farmland than in soil in the surface layer, and radiocaesium more than 99 % in soil at locations that are supposed to have been used as farmland also distributed within a depth of around 14 cm. The apparent diffusion coefficients (Da) of RNs derived from penetration profiles near the surface layer showed a tendency to be higher in soil at locations that are supposed to have been used as farmland (Da=0.1-1.5x10-10 m2/s) than in soil in the surface layer (Da=0.65-4.4x10-11 m2/s), and most Da-values were nearly 10-11 m2/s. The distribution coefficients (Kd) by a batch method were in the range of Kd=2,000-61,000 ml/g for Cs and Kd=0.5-140 ml/g for I. Although the Kd-values are different between cation (Cs+) and anion (I-), the Da-values (134Cs, 137Cs, 129mTe and 110mAg) were similar levels. This is considered to be due to that the Da-values were controlled by dispersion by flow of rain water.

scholarly journals Radiation dose rates now and in the future for residents neighboring restricted areas of the Fukushima Daiichi Nuclear Power Plant

2014 ◽  
Vol 111 (10) ◽  
pp. E914-E923 ◽  
Author(s):  
Kouji H. Harada ◽  
Tamon Niisoe ◽  
Mie Imanaka ◽  
Tomoyuki Takahashi ◽  
Katsumi Amako ◽  
...  
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Radiation Dose ◽  
Radiation Exposure ◽  
Dose Rate ◽  
Nuclear Power ◽  
Solid Cancer ◽  
External Dose ◽  
Dose Rates ◽  
Fukushima Daiichi

Radiation dose rates were evaluated in three areas neighboring a restricted area within a 20- to 50-km radius of the Fukushima Daiichi Nuclear Power Plant in August–September 2012 and projected to 2022 and 2062. Study participants wore personal dosimeters measuring external dose equivalents, almost entirely from deposited radionuclides (groundshine). External dose rate equivalents owing to the accident averaged 1.03, 2.75, and 1.66 mSv/y in the village of Kawauchi, the Tamano area of Soma, and the Haramachi area of Minamisoma, respectively. Internal dose rates estimated from dietary intake of radiocesium averaged 0.0058, 0.019, and 0.0088 mSv/y in Kawauchi, Tamano, and Haramachi, respectively. Dose rates from inhalation of resuspended radiocesium were lower than 0.001 mSv/y. In 2012, the average annual doses from radiocesium were close to the average background radiation exposure (2 mSv/y) in Japan. Accounting only for the physical decay of radiocesium, mean annual dose rates in 2022 were estimated as 0.31, 0.87, and 0.53 mSv/y in Kawauchi, Tamano, and Haramachi, respectively. The simple and conservative estimates are comparable with variations in the background dose, and unlikely to exceed the ordinary permissible dose rate (1 mSv/y) for the majority of the Fukushima population. Health risk assessment indicates that post-2012 doses will increase lifetime solid cancer, leukemia, and breast cancer incidences by 1.06%, 0.03% and 0.28% respectively, in Tamano. This assessment was derived from short-term observation with uncertainties and did not evaluate the first-year dose and radioiodine exposure. Nevertheless, this estimate provides perspective on the long-term radiation exposure levels in the three regions.

scholarly journals Visualization of Radiocesium Distribution in Surface Layer of Seafloor Around Fukushima Daiichi Nuclear Power Plant

2021 ◽  
Author(s):  
Yukihisa Sanada ◽  
Yoshimi Urabe ◽  
Toshiharu Misonou ◽  
Takehiko Shiribiki ◽  
Takahiro Nakanishi ◽  
...  
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Sediment Core ◽  
Nuclear Power ◽  
Gamma Ray ◽  
Detection System ◽  
Aquatic Organisms ◽  
Core Sample ◽  
Seafloor Topography ◽  
Fukushima Daiichi

Abstract Large quantities of volatile radionuclides were released into the atmosphere and the hydrosphere following the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident on March 11, 2011. Monitoring of radiocesium in sediment is important for evaluating the behavior of radiocesium in the environment and its effect on aquatic organisms. In this study, the radiocesium distribution in the surface sediment around the FDNPP was visualized as a radiocesium map using periodical survey data from a towed gamma-ray detection system. The uncertainty of the radiocesium map was evaluated via comparison with a large amount of sediment core sample data. The characteristics of the radiocesium distribution were examined considering the seafloor topography and a geological map, which were obtained via acoustic wave survey. The characteristics of the formation of 137Cs anomaly at the estuaries were analyzed using a contour map of 137Cs concentration combined with water depth. Validation of the created map showed that it was comparable with actual sediment core samples. The map generated using the towed radiation survey depicted the 137Cs concentration distribution as the position resolution of a 1 km mesh. Finally, the 137Cs concentration decreased with time in consideration of such uncertainty.

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