This website uses cookies. Read about how we use cookies. OK

                               

Accumulated absorbed dose rate - T=13.03.2011 - 20.06.2018(see missing values above)

< Acc. Vmax < 2 * Acc. Vmax < 4 * Acc. Vmax > 4 * Ac.. Vmax
Stations: 353 Acc. abs. dose rate
μGy/T
Acc. Vmax
μGy/T
Acc. Vmean
μGy/T
Fukushima I MP7 696005.000 7182
Fukushima I MP8 570942.000 7182
Fukushima I MP6 240668.000 7182
Yamada Futaba Town 176983.000 5655.07 6738.77
Fukushima I MP2 140420.000 7182
Fukushima I MP5 111325.000 7182
Fukushima [32] (distance from Fukushima I: 30 km) 101500.000 4517.3 7253.14
Fukushima I MP3 93730.602 7182
Fukushima I MP4 86821.500 7182
Fukushima [33] (distance from Fukushima I: 30 km) 77197.703 4517.3 7253.14
Fukushima [79] (distance from Fukushima I: 40 km) 54008.602 4466.18 7171.06
Fukushima [31] (distance from Fukushima I: 30 km) 40677.398 4517.3 7253.14
Ono Okuma Town 38610.500 5221.54 6738.77
Shinzan Futaba Town 38332.801 4738.83 6738.77
Fukushima I MP1 31496.801 7182
Yonomori Tomioka Town 29815.900 5398.88 6738.77
Fukushima [46] (distance from Fukushima I: 20 km) 28842.500 4517.3 7253.14
Tomioka Tomioka Town 25324.500 5812.66 6738.77
Fukushima [62] (distance from Fukushima I: 40 km) 16464.100 4517.3 7253.14
Fukushima [61] (distance from Fukushima I: 40 km) 13102.800 4517.3 7253.14
Shimo-Kooriyama Tomioka Town 13057.000 5773.29 6738.77
Fukushima [21] (distance from Fukushima I: 30 km) 12103.800 4517.3 7253.14
Fukushima [3] (distance from Fukushima I: 45 km) 11985.000 4517.3 7253.14
Kami-kooriyama Tomioka Town 11803.900 4531.94 6738.77
Fukushima II MP3 11060.600 7182
Fukushima II MP1 10903.000 7182
Kooriyama Futaba Town 10352.900 5280.65 6738.77
Fukushima II MP4 9696.330 7182
Fukushima [34] (distance from Fukushima I: 30 km) 9540.450 4513.9 7247.66
Fukushima II MP5 9382.150 7182
Fukushima [2] (distance from Fukushima I: 55 km) 8841.760 4517.3 7253.14
Matsudate Naraha Town 8410.890 6167.33 6738.77
Shigeoka Naraha Town 8115.970 6817.56 6738.77
Fukushima II MP2 7875.320 7182
Namie Namie Town 7321.210 4975.28 6738.77
Radiation dose at Shirasawa branch office, Motomiya 7287.920 7198.42
Fukushima II MP6 7062.690 7182
Fukushima II MP7 6511.580 7179.26
Fukushima [1] (distance from Fukushima I: 60 km) 5615.310 4517.3 7253.14
Fukushima [11] (distance from Fukushima I: 40 km) 5491.310 4517.3 7253.14
Fukushima [63] (distance from Fukushima I: 45 km) 5448.820 4517.3 7253.14
Fukushima [45] (distance from Fukushima I: 20 km) 3981.200 4517.3 7253.14
Fukushima [42] (distance from Fukushima I: 30 km) 3850.600 4517.3 7253.14
Fukushima [10] (distance from Fukushima I: 40 km) 3734.160 4517.3 7253.14
Fukushima [78] (distance from Fukushima I: 45 km) 3716.820 4512.19 7244.93
Futatsunuma Hirono Town 3520.340 5911.2 6738.77
Fukushima [4] (distance from Fukushima I: 50 km) 3386.310 4517.3 7253.14
Fukushima [7] (distance from Fukushima I: 45 km) 3313.930 4517.3 7253.14
Radiation dose at Koriyama joint government building, Koriyama 3232.890 7195.68
Fukushima [15] (distance from Fukushima I: 35 km) 3178.670 4517.3 7253.14
Kiyohashi Namie Town 3162.000 4364.42 6738.77
Fukushima [71] (distance from Fukushima I: 25 km) 3161.650 4512.19 7244.93
Radiation dose at Agricultural center, Koriyama 3128.960 7195.68
Fukushima [41] (distance from Fukushima I: 20 km) 3111.490 4517.3 7253.14
Radiation dose at Koriyama city office, Koriyama 2803.520 7195.68
Fukushima [44] (distance from Fukushima I: 30 km) 2535.550 4517.3 7253.14
Fukushima [72] (distance from Fukushima I: 30 km) 2344.620 4512.19 7244.93
Fukushima [43] (distance from Fukushima I: 20 km) 2244.110 4517.3 7253.14
Yamadaoka Naraha Town 2205.340 5241.28 6738.77
Radiation dose at Iwane Fureai Plaza, Motomiya 2169.060 7198.42
Fukushima [22] (distance from Fukushima I: 35 km) 2020.650 4517.3 7253.14
Kuji Hitachi City 1990.890 11214.7 7264.08
Hitachinaka Hitachinaka City 1951.950 4925.8 7261.34
Fukushima [76] (distance from Fukushima I: 25 km) 1945.520 4512.19 7244.93
Fukushima [80] (distance from Fukushima I: 25 km) 1876.860 4512.19 7244.93
Momiyama Hokota City 1837.540 5618 7264.08
Fukushima [77] (distance from Fukushima I: 25 km) 1802.490 4512.19 7244.93
Horiguchi Hitachinaka City 1779.410 4908.29 7266.82
Onuma Hitachi City 1776.950 4182.73 7261.34
Fukushima [6] (distance from Fukushima I: 45 km) 1741.180 4517.3 7253.14
Tsukuriya Hokota City 1736.890 4725.92 7264.08
Radiation dose at Big palette Fukushima, Koriyama 1668.540 7195.68
Nemoto Hitachioomiya City 1633.190 5265.56 7261.34
Fukushima [13] (distance from Fukushima I: 40 km) 1624.150 4517.3 7253.14
Fukushima [23] (distance from Fukushima I: 35 km) 1551.750 4517.3 7253.14
Radiation dose at Tsukidatemachi kamitedo, Date 1545.300 7203.89
Fukushima [14] (distance from Fukushima I: 35 km) 1543.460 4517.3 7253.14
Radiation dose at JAEA Oarai (P12) 1512.140 7220.3
Radiation dose at Ose administration center, Koriyama 1494.270 7195.68
Araji Hokota City 1437.760 4736.5 7264.08
Ishigami Tokai Village 1431.690 4311.74 7264.08
Mawatari Hitachinaka City 1422.870 4980.8 7264.08
Radiation dose at JAEA Oarai (P11) 1399.370 7220.3
Onuki Oarai Town 1387.990 5171.96 7264.08
Sawa Hitachinaka City 1353.770 3906.67 7261.34
Toyooka Tokai Village 1321.760 4747.14 7264.08
Ajigaura Hitachinaka City 1313.890 4671.02 7261.34
Fukushima [5] (distance from Fukushima I: 45 km) 1282.090 4517.3 7253.14
Geiger Counter Feeds from Asao Kawasaki 1266.620 7173.79
Radiation dose at Tamokami elementary school, Koriyama 1256.140 7195.68
Isohama Oarai Town 1250.540 4510.08 7258.61
Ebisawa Ibaraki Town 1222.240 12242.4 7261.34
Muramatsu Tokai Village 1203.520 4789.64 7264.08
Kamitoda Hokota City 1184.740 3929.42 7264.08
Yanagisawa Hitachinaka City 1166.970 4002.21 7261.34
Tokushuku Hokota City 1159.730 3547.1 7264.08
Tasaki Hokota City 1153.300 4198.69 7233.98
Fukushima [20] (distance from Fukushima I: 45 km) 1145.390 4517.3 7253.14
Kadobe Naka City 1086.580 9533.19 7261.34
Radiation dose at Date city office, Date 1076.050 7198.42
Oshinobe Tokai Village 1041.340 4471.04 7264.08
Oba Mito City 1037.670 14687.5 7264.08
Godai Naka City 1031.270 3876.28 7264.08
Ishikawa Mito City 1030.810 4568.34 7266.82
Isobe Hitachiota City 1013.130 22047.1 7264.08
Yatabe Ibaraki Town 996.127 3833.84 7264.08
Radiation dose at Motomiya city office, Motomiya 992.703 7198.42
Fukushima [73] (distance from Fukushima I: 35 km) 981.984 4512.19 7244.93
Fukushima [75] (distance from Fukushima I: 45 km) 960.529 4512.19 7244.93
Yokobori Naka City 930.280 4492.26 7264.08
Sugaya Naka City 926.186 6863.12 7266.82
Kounosu Naka City 926.087 3504.6 7264.08
Funaishikawa Tokai Village 900.399 4651.56 7264.08
Nukada Naka City 899.900 4202.35 7258.61
Uridura Naka City 890.113 4011.34 7258.61
Shiraki Tsuruga City 881.330 8509.82 7266.82
Motokomezaki Naka City 880.851 3742.49 7231.25
Shiraki pass Tsuruga City 850.284 8913.51 7266.82
Radiation dose in Yamamoto 846.633 7220.3
Yoshizawa Mito City 837.646 4056.86 7264.08
Radiation dose at JAEA Oarai (P7) 831.135 7220.3
Mayumi Hitachiota City 828.119 4025 7264.08
Urasoko Tsuruga City 826.465 7064.94 7266.82
Nemoto Hitachioomiya City 825.588 4533.05 7261.34
Takenami Mihama Town 804.283 7415.53 7266.82
Radiation dose at JAEA Oarai (P15) 780.207 7220.3
Tateishi Tsuruga City 780.092 5875.09 7266.82
Radiation dose at JAEA Oarai (P14) 770.174 7220.3
Radiation dose at JAEA Oarai (P13) 769.612 7220.3
Ukishima Kawasaki Ward 735.475 13864.3 7266.82
Kume Hitachiota City 713.958 3940 7264.08
Radiation dose at JAEA Oarai (P2) 712.011 7220.3
Fukushima [74] (distance from Fukushima I: 35 km) 706.552 4512.19 7244.93
Nyuu Mihama Town 674.787 6756.86 7266.82
Fukushima [52] (distance from Fukushima I: 40 km) 672.743 4517.3 7253.14
Radiation dose in Iwanuma 670.242 7220.3
Fukushima [51] (distance from Fukushima I: 40 km) 665.376 4517.3 7253.14
Tsuruga Tsuruga City 655.360 5960.06 7266.82
Shiohama Kawasaki Ward 653.536 4759.57 7266.82
Radiation dose in Kakuda 649.863 7220.3
Sakajiri Mihama Town 649.252 7883.03 7266.82
North point of Kinki University Atomic Energy Research Instirute Station 639.566 4950.81 7266.82
Radiation dose in Onagawa (MP-2) 632.968 7217.57
Kumatori town Nishi primary school Station 631.491 5917.55 7266.82
Oshima Kawasaki Ward 630.402 4536.47 7266.82
Izumisano municipal Oike athletic field Station 629.920 6671.89 7266.82
Atom-kyoudou nursery school Station 625.566 6406.27 7266.82
South point of Kinki University Atomic Energy Research Instirute Station 625.202 5832.58 7266.82
Nakamachi Omaezaki City 623.494 7511.15 7266.82
Uraga Yokosuka City 622.492 3559.02 7266.82
Goritoge Shika Town 622.143 7978.65 7266.82
Kumatori town Minami primary school Station 606.134 6788.74 7266.82
Radiation dose at JAEA Oarai (P1) 603.643 7223.04
Yamanotedai-No.1 Park Station 599.140 6331.88 7266.82
Radiation via www.houshasen-pref-ibaraki.jp (unofficial information) 595.502 7239.46
Noumi Shika Town 594.021 7893.61 7266.82
Radiation dose in Watari 591.851 7220.3
Hairando Yokosuka City 588.667 4462.08 7266.82
Fukushima [12] (distance from Fukushima I: 40 km) 588.291 4517.3 7253.14
Ningyotoge Kagamino Town 574.857 6331.88 7266.82
Ten-no Kagamino Town 569.960 7585.54 7266.82
Funagura Yokosuka City 563.909 4207.1 7266.82
Chidori Kawasaki Ward 560.211 4068.97 7266.82
Radiation dose at JAEA Oarai (P16) 556.365 7220.3
Shika Shika Town 551.376 7606.76 7266.82
Higashiosaka municipal Kamikosaka primary scool Station 550.277 4940.16 7266.82
Sahara Yokosuka City 547.404 3941.48 7266.82
Kazanashi Shika Town 545.377 7139.33 7266.82
Akasumi Shika Town 544.970 6533.76 7266.82
Kurahashi Maizuru City 540.820 5949.42 7266.82
Obama Obama City 540.809 5322.62 7266.82
Sakuragaike community hall Omaezaki City 540.772 7702.38 7266.82
Shirowa primary school Omaezaki City 535.692 7543.02 7266.82
Radiation dose at JAEA Oarai (P5) 529.759 7220.3
Uenohara Omaezaki City 529.333 7755.54 7266.82
Kumano Shika Town 529.019 7404.95 7266.82
Izumisano municipal Hineno filtration plant Station 527.471 6385.05 7266.82
Nishi-hamasada Matsue City 525.089 7070.22 7250.4
Kouno Minami-Echizen Town 525.028 5354.5 7266.82
Kurihama Yokosuka City 523.708 4260.2 7266.82
Osaka prefectural Kumatori off-site-center Station 522.808 5885.67 7266.82
Ogasa branch Kikugawa City 522.039 7846.94 7253.14
Izumisano municipal Hineno primary scool Station 518.181 5110.17 7266.82
Shirasuna Omaezaki City 499.479 7596.18 7266.82
Jitougata primary school Makinohara City 498.059 7288.04 7266.82
Kataku Matsue City 497.007 5662.57 7266.82
Nishihemi Yokosuka City 496.917 3399.66 7266.82
Radiation via www.houshasen-pref-ibaraki.jp (unofficial information) 496.721 7239.46
Satsuma-sendai monitoring center Satsuma-sendai City 495.302 5577.6 7266.82
Otomi Takahama Town 494.821 6246.91 7266.82
Otsu Nanao City 493.895 6268.14 7266.82
The Observation point for comparison Tatsunokuchi 493.454 5163.26 7266.82
Hitsuhama Ohi Town 492.630 5811.35 7266.82
Kijiyama Misasa Town 489.284 5896.32 7266.82
Radiation via www.houshasen-pref-ibaraki.jp (unofficial information) 487.055 7239.46
Hiraba Omaezaki City 485.878 7596.18 7266.82
Tayu Matsue City 484.956 5906.97 7266.82
Hamaokakita primary school Omaezaki City 484.537 7793.94 7253.14
Oitomi Ayabe City 474.670 7489.92 7266.82
Radiation via www.houshasen-pref-ibaraki.jp (unofficial information) 472.017 7239.46
Kashiwazaki-shigai Kashiwazaki City 470.822 5960.06 7266.82
Mitsu Matsue City 466.897 5651.99 7266.82
Tonomachi Kawasaki Ward 463.967 7160.55 7266.82
Daitou branch Kakegawa City 463.829 7677.32 7253.14
Fukura Shika Town 462.493 7128.68 7266.82
Nagasawa Yokosuka City 462.365 4164.59 7266.82
The athletic field Station of Kinki University 461.661 4706.41 7266.82
Koura Matsue City 461.049 6746.22 7266.82
Sakurasan Ward Omaezaki City 459.434 7351.79 7266.82
Tsuchikawa Nanao City 458.915 6937.45 7266.82
Kumatori Town office Station 457.917 4855.19 7266.82
Shinkango Omaezaki City 449.013 8509.82 7266.82
Ogurui Takahama Town 448.279 5566.95 7266.82
Kusabue Omaezaki City 444.162 8021.1 7266.82
Omaezaki City monitoring center 443.946 7872.38 7266.82
Akawase Kagamino Town 442.246 4855.19 7266.82
Ibaraki 442.139 3565.63 7258.61
Hinode Town Yokosuka City 438.324 2804.74 7266.82
Nishiyama Kashiwazaki City 437.251 8435.43 7266.82
Kariwa Kariwa Village 436.307 6363.75 7266.82
Osaka prefectural Hineno high scool Station 435.745 5673.22 7266.82
Miyagawa Kashiwazaki City 435.245 6278.78 7266.82
Radiation dose in Natori 434.640 7220.3
Kami-koubu Matsue City 433.868 6172.52 7266.82
Shimo-Takamachi Kariwa Village 433.192 6926.87 7266.82
Osaka prefectural Sano supporting school Station 432.398 6183.17 7266.82
Arahama Kashiwazaki City 428.874 6470.02 7266.82
Doai Kashiwazaki City 425.681 6087.55 7266.82
Owashi Matsue City 424.452 6034.45 7266.82
Okayasu Maizuru City 422.568 7107.46 7266.82
Katsuyama Kariwa Village 421.280 6470.02 7266.82
Kita-koubu Matsue City 420.683 6618.73 7266.82
Kichisaka Maizuru City 413.065 8637.31 7266.82
Nagai Ohi Town 410.699 6282.33 7258.61
Shiokumi Maizuru City 407.938 10751.5 7266.82
Miyadome Ohi Town 407.831 5205.78 7266.82
Kariwa Kariwa Village 407.617 6703.77 7266.82
Ueno Satsuma-sendai City 394.248 4865.77 7266.82
Power Station-South 389.191 7086.23 7266.82
Radiation dose at JAEA Oarai (P6) 386.963 7220.3
Power Station- 385.546 6916.22 7266.82
Takae Satsuma-sendai City 379.551 4929.52 7266.82
Hokawaduura Genkai Town 378.015 7505.86 7266.82
Kou Itimatsu Suetsugu 377.929 5418.24 7266.82
Minato Satsuma-sendai City 377.656 4515.18 7266.82
Iwanai Iwanai Town 376.336 7359.66 7264.08
Hattari Kyowa Town 373.047 7157.86 7264.08
Chatsu Tomari Village 371.011 6839.26 7264.08
Oyama Maizuru City 358.223 6225.69 7266.82
Kodaira Satsuma-sendai City 355.545 4568.34 7266.82
Kayanuma Tomari Village 354.809 6085.26 7264.08
Anojiri Obama City 353.215 5099.52 7266.82
Kushi Genkai Town 349.738 10358.4 7266.82
Yamaguchi 348.715 8150.02 7258.61
Sadahongou Matsue City 348.228 6342.53 7266.82
Sakibe Karatsu City 347.801 9816.58 7266.82
Hirao Genkai Town 343.814 10347.8 7266.82
The Meteorological Obsevatory of kyowa Town 343.275 6786.18 7264.08
Minami-Horoni Kyowa Town 335.180 6361.36 7264.08
Kounoura Takahama Town 330.353 5375.72 7266.82
Kyoudomarisaki Karatsu City 328.622 10517.8 7266.82
Horikappu Jinja Tomari Village 328.230 6584.38 7264.08
Hukada-kita Matsue City 327.031 5216.36 7266.82
Radiation dose in KEK, Tsukuba 326.240 7239.46
Herokaruusu Tomari Village 324.242 6828.68 7264.08
Yorita Satsuma-sendai City 323.218 5343.85 7266.82
Kamoenai Kamoenai Village 322.032 5766.66 7264.08
Radiation dose in Onagawa (MP-6) 316.267 7217.57
Imamura Genkai Town 314.749 89135.1 7266.82
Yamanaka Takahama Town 314.185 6937.45 7266.82
Sendai (Miyagi) 312.585 3266.37 7258.61
Radiation dose in Onagawa (MP-1) 300.147 7217.57
Gumisaki Satsuma-sendai City 295.693 4313.37 7266.82
Radiation via www.houshasen-pref-ibaraki.jp (unofficial information) 286.142 7239.46
Aomori Aomori City 285.372 4386.04 7264.08
Misawa City hall Misawa City 283.728 8506.62 7264.08
Kashu Ikata Town 277.173 4451.44 7266.82
Noheji Town Office Noheji Town 272.004 3759.48 7264.08
Takasimamati 271.103 4738.28 7266.82
Radiation dose in Onagawa (MP-3) 270.563 7217.57
Kucho Ikata Town 269.545 3930.9 7266.82
Radiation dose in Marumori 269.436 7220.3
Kawanagata Ikata Town 266.821 3835.29 7266.82
Tochigi 260.733 4266.02 7258.61
Chikagawa Mutu City 256.719 4895.8 7264.08
Yokohama Town Office Yokohama Town 254.846 6000.32 7264.08
Tokyo 251.877 5030.09 7258.61
Hiranuma Rokkasho Village 251.186 3940 7264.08
Taisei Ikata Town 246.293 2879.13 7266.82
Chitose-daira Rokkasho Village 245.868 4248.02 7264.08
Gifu 243.951 7003.92 7258.61
Fukkoshi Yokohama Town 243.102 4120.58 7264.08
Shimane 240.651 7003.92 7258.61
Sunagomata Higashidoori Village 238.012 5957.82 7264.08
Obuchi Rokkasho Village 237.506 4736.5 7264.08
Tomari Rokkasho Village 230.636 6626.88 7264.08
kanagawa 226.339 4393.37 7258.61
Saitama 219.770 3820.32 7258.61
Ikatagoshi Ikata Town 217.515 3622.76 7266.82
Touhoku Branch office Touhoku Town 215.416 3430.24 7264.08
Radiation dose at Tohoku University 214.824 7220.3
Odanosawa Higashidoori Village 210.287 4747.14 7264.08
Kagawa 205.829 4902.74 7258.61
Oippe Higashidoori Village 205.182 4088.72 7264.08
Oita 200.921 5412.12 7258.61
Touhoku Town office Touhoku Town 200.811 15866.3 7264.08
Kuchogoshi Ikata Town 198.646 3675.93 7266.82
Minatoura Ikata Town 186.776 3304.04 7266.82
Radiation dose in Koyadori, Ojika 184.905 7214.83
Toyama 184.580 9359.78 7258.61
Fukushima [9] (distance from Fukushima I: 45 km) 184.232 4517.3 7253.14
Radiation dose in Tukahama, Ojika 183.417 7214.83
Chiba 182.407 2801.57 7258.61
Nara 182.387 5093.76 7258.61
Okayama 181.976 6621.89 7258.61
Yamagata 181.598 5221.1 7258.61
Ehime 180.745 4711.73 7258.61
Ishikawa 180.445 8118.18 7258.61
Niigata 177.483 9741.82 7258.61
Hiroshima 176.816 4393.37 7258.61
Mie 174.867 5023.72 7258.61
Fukui 170.045 6176.18 7258.61
Radiation dose in Terama, Ojika 168.036 7214.83
Yamanashi 164.561 4075.01 7258.61
Nagano 162.242 6201.65 7258.61
Saga 161.421 5475.79 7258.61
Tottori 161.392 5030.09 7258.61
Radiation dose in Enoshima, Ojika 160.091 7214.83
Osaka 159.103 3883.99 7258.61
Ibaraki-city Environment 157.249 7173.79
Aichi 149.345 4711.73 7258.61
Toyonoura Ikata Town 149.214 3792.77 7266.82
Shizuoka 148.639 4870.91 7258.61
Kyoto 144.522 5539.46 7258.61
Kagoshima 144.449 6004.27 7258.61
Tokushima 143.627 4266.02 7258.61
Gunma 143.572 2865.24 7258.61
Hyogo 139.710 4839.07 7258.61
Fukuoka 136.511 5030.09 7258.61
Wakayama 133.857 3565.63 7258.61
Radiation at Tamaki-cho Mie Japan 133.138 7173.79
Akita 132.832 5475.79 7258.61
Shiga 124.919 3883.99 7258.61
Nagasaki 109.459 4393.37 7258.61
Hokkaido 109.189 6685.56 7258.61
Kumamoto 103.568 4266.02 7258.61
Aomori 101.819 6494.54 7258.61
Miyazaki 100.354 4227.82 7258.61
Kochi 95.931 4839.07 7258.61
Fukushima [35] (distance from Fukushima I: 35 km) 91.917 4508.78 7239.46
Iwate 90.324 5348.45 7258.61
Environment Feeds from Ohta 83.623 7173.79
Okinawa 82.305 3661.14 7258.61
Units: absorbed dose rate [μGy/h]
  • In cases of x-rays and gamma rays and electrons absorbed by human tissue Gray is often converted into Sievert by assuming 1 Gy/h = 1 SV/h (see information below).
    Roentgen equivalent in man (rem): 1 Sv = 100 rem
  • Please note: The y-axis displaying the absorbed dose rate and accumulation plots can vary depending on location and time frame.


Data source - Absorbed dose rate:
Dataset 1 Dataset 2 Dataset 3 Dataset 4
Source MEXT Readings MEXT (SPEEDI) TEPCO Pachube
Data available since 13.3.2011 or 15.3.2011
hourly averages
since 1.1.2010
10 minute data
since 14.4.2011
10 minute data
since 22.3.2011
different sources with 10 minute data or hourly averages
 
hourly averages hourly averages hourly averages hourly averages
 
band Vmax-Vmin
Minimum value (Vmin) and maximum value (Vmax) from usual value band: "Usual value band means a range of the maximum and minimum value observed before the earthquake" [MEXT: e.g. pdf]) Minimum value (Vmin) and maximum value (Vmax) calculated with the data of the respective locations from 1.1.2010 to 10.3.2011 (from hourly averages) no value band no value band
Sometimes data is not transmitted due to maintenance or for other reasons. Missing data is not bridged by lines. Only values refering to sequential hours are connected.


Accumulated absorbed dose rate:
Dataset 1, Dataset 2, Dataset 3 and Dataset 4
 
Accumulated dose rate = summation of hourly averages of absorbed dose rate
Accumulation period: 13.3.2011 up to today
Accumulation of original data

Missing values:
Accumulation of interpolated data:
Missing values are approximated since original data of average absorbed dose rate is not available for every hour. Missing data points are computed by linear interpolation.
Missing data at the beginning of the period:
Missing values at the beginning of the accumulation period (13.3.) will be set to 0.
In those cases the calculated accumulation values show below the actual accumulation values. Regarding the assessment of the timeline: Radiation releases during the initial hydrogen explosions.
All data taken into account in the accumulation is shown in the graph ‘interpolated raw data’ (top left button above the graph).
 
The red graph shows the accumulation of 0,114 μGy/h based on an estimated average for Japan of 1000 μGy per year (equates 0,114 μGy/h *24 hours * 365 days). The accumulation starts with the first available value of the data set after 13.3.2011 (see missing values above).
 
The green graph shows the accumulation of Vmax. The accumulation starts with the first available value of the data set after 13.3.2011 (see missing values above).



Colour scale:
< Vmax < 10 * Vmax < 100 * Vmax > 100 * Vmax
The colour scale is based on the maximum Value (Vmax) measured at the location of the Geiger counter prior to the accident. Therefore allowing to spell out the changes in comparison to the values prior to the accident.
Natural radiation:
Health effects - information:
Units: absorbed dose rate [Gy/h]

Absorbed dose [Gy]:

The unit gray, [Gy], measures radiation which is absorbed into any material.


Equivalent dose [Sv]:

The unit sievert, [Sv], specifically measures radiation which is absorbed by a person.
The equivalent dose to a person is found by multiplying the absorbed dose, in gray, by a radiation weighting factor (WR ).
The radiation weighting factor WR is introduced to allow for the different relative biological effects of different types of ionizing radiation on human tissue.

In terms of SI base units:

1 Sv = 1 Gy ⋅ WR

where Sv=sievert, Gy=gray, WR =weighting factor specific to each type of radiation and tissue.

Radiation weighting factor (WR ):

For x-rays and gamma rays and electrons absorbed by human tissue, WR is 1. For alpha particles it is 20. To compute Sieverts from Grays, simply multiply by WR . This is obviously a simplification. The radiation weighting factor WR approximates what otherwise would be very complicated computations. The values for WR change periodically as new research refines the approximations [1].


Effective dose [Sv]:

The probability of a harmful effect from radiation exposure depends on what part or parts of the body are exposed. Some organs are more sensitive to radiation than others. A tissue weighting factor is used to take this into account. When an equivalent dose to an organ is multiplied by the tissue weighting factor for that organ the result is the effective dose to that organ. If more than one organ is exposed then the effective dose, is the sum of the effective doses to all exposed organs [1].

Tissue weighting factor:

see table European nuclear society


more information:

Fukushima I Nuclear power plant

ATTENTION: These products are highly uncertain based on limited information for the source terms. Please use with caution and understand that the values are likely to change.
Cloud spread Fukushima
Cloud spread Fukushima
Cloud spread Fukushima
Summary

Japan nuclear accident