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

                               

Accumulated absorbed dose rate - T=13.03.2011 - 27.08.2016(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 5370.77
Fukushima I MP8 570942.000 5370.77
Fukushima I MP6 240668.000 5370.77
Yamada Futaba Town 176983.000 4135.11 4927.54
Fukushima I MP2 140420.000 5370.77
Fukushima I MP5 111325.000 5370.77
Fukushima [32] (distance from Fukushima I: 30 km) 101500.000 3389.26 5441.9
Fukushima I MP3 93730.602 5370.77
Fukushima I MP4 86821.500 5370.77
Fukushima [33] (distance from Fukushima I: 30 km) 77197.703 3389.26 5441.9
Fukushima [79] (distance from Fukushima I: 40 km) 54008.602 3338.14 5359.82
Fukushima [31] (distance from Fukushima I: 30 km) 40677.398 3389.26 5441.9
Ono Okuma Town 38610.500 3818.11 4927.54
Shinzan Futaba Town 38332.801 3465.14 4927.54
Fukushima I MP1 31496.801 5370.77
Yonomori Tomioka Town 29815.900 3947.78 4927.54
Fukushima [46] (distance from Fukushima I: 20 km) 28842.500 3389.26 5441.9
Tomioka Tomioka Town 25324.500 4250.35 4927.54
Fukushima [62] (distance from Fukushima I: 40 km) 16464.100 3389.26 5441.9
Fukushima [61] (distance from Fukushima I: 40 km) 13102.800 3389.26 5441.9
Shimo-Kooriyama Tomioka Town 13057.000 4221.56 4927.54
Fukushima [21] (distance from Fukushima I: 30 km) 12103.800 3389.26 5441.9
Fukushima [3] (distance from Fukushima I: 45 km) 11985.000 3389.26 5441.9
Kami-kooriyama Tomioka Town 11803.900 3313.85 4927.54
Fukushima II MP3 11060.600 5370.77
Fukushima II MP1 10903.000 5370.77
Kooriyama Futaba Town 10352.900 3861.33 4927.54
Fukushima II MP4 9696.330 5370.77
Fukushima [34] (distance from Fukushima I: 30 km) 9540.450 3385.85 5436.43
Fukushima II MP5 9382.150 5370.77
Fukushima [2] (distance from Fukushima I: 55 km) 8841.760 3389.26 5441.9
Matsudate Naraha Town 8410.890 4509.69 4927.54
Shigeoka Naraha Town 8115.970 4985.15 4927.54
Fukushima II MP2 7875.320 5370.77
Namie Namie Town 7321.210 3638.03 4927.54
Radiation dose at Shirasawa branch office, Motomiya 7287.920 5387.18
Fukushima II MP6 7062.690 5370.77
Fukushima II MP7 6511.580 5368.03
Fukushima [1] (distance from Fukushima I: 60 km) 5615.310 3389.26 5441.9
Fukushima [11] (distance from Fukushima I: 40 km) 5491.310 3389.26 5441.9
Fukushima [63] (distance from Fukushima I: 45 km) 5448.820 3389.26 5441.9
Fukushima [45] (distance from Fukushima I: 20 km) 3981.200 3389.26 5441.9
Fukushima [42] (distance from Fukushima I: 30 km) 3850.600 3389.26 5441.9
Fukushima [10] (distance from Fukushima I: 40 km) 3734.160 3389.26 5441.9
Fukushima [78] (distance from Fukushima I: 45 km) 3716.820 3384.14 5433.7
Futatsunuma Hirono Town 3520.340 4322.4 4927.54
Fukushima [4] (distance from Fukushima I: 50 km) 3386.310 3389.26 5441.9
Fukushima [7] (distance from Fukushima I: 45 km) 3313.930 3389.26 5441.9
Radiation dose at Koriyama joint government building, Koriyama 3232.890 5384.45
Fukushima [15] (distance from Fukushima I: 35 km) 3178.670 3389.26 5441.9
Kiyohashi Namie Town 3162.000 3191.36 4927.54
Fukushima [71] (distance from Fukushima I: 25 km) 3161.650 3384.14 5433.7
Radiation dose at Agricultural center, Koriyama 3128.960 5384.45
Fukushima [41] (distance from Fukushima I: 20 km) 3111.490 3389.26 5441.9
Radiation dose at Koriyama city office, Koriyama 2803.520 5384.45
Fukushima [44] (distance from Fukushima I: 30 km) 2535.550 3389.26 5441.9
Fukushima [72] (distance from Fukushima I: 30 km) 2344.620 3384.14 5433.7
Fukushima [43] (distance from Fukushima I: 20 km) 2244.110 3389.26 5441.9
Yamadaoka Naraha Town 2205.340 3832.54 4927.54
Radiation dose at Iwane Fureai Plaza, Motomiya 2169.060 5387.18
Fukushima [22] (distance from Fukushima I: 35 km) 2020.650 3389.26 5441.9
Kuji Hitachi City 1990.890 8418.43 5452.85
Hitachinaka Hitachinaka City 1951.950 3697.14 5450.11
Fukushima [76] (distance from Fukushima I: 25 km) 1945.520 3384.14 5433.7
Fukushima [80] (distance from Fukushima I: 25 km) 1876.860 3384.14 5433.7
Momiyama Hokota City 1837.540 4217.2 5452.85
Fukushima [77] (distance from Fukushima I: 25 km) 1802.490 3384.14 5433.7
Horiguchi Hitachinaka City 1779.410 3684.91 5455.58
Onuma Hitachi City 1776.950 3139.41 5450.11
Fukushima [6] (distance from Fukushima I: 45 km) 1741.180 3389.26 5441.9
Tsukuriya Hokota City 1736.890 3547.56 5452.85
Radiation dose at Big palette Fukushima, Koriyama 1668.540 5384.45
Nemoto Hitachioomiya City 1633.190 3952.14 5450.11
Fukushima [13] (distance from Fukushima I: 40 km) 1624.150 3389.26 5441.9
Fukushima [23] (distance from Fukushima I: 35 km) 1551.750 3389.26 5441.9
Radiation dose at Tsukidatemachi kamitedo, Date 1545.300 5392.66
Fukushima [14] (distance from Fukushima I: 35 km) 1543.460 3389.26 5441.9
Radiation dose at JAEA Oarai (P12) 1512.140 5409.07
Radiation dose at Ose administration center, Koriyama 1494.270 5384.45
Araji Hokota City 1437.760 3555.5 5452.85
Ishigami Tokai Village 1431.690 3236.65 5452.85
Mawatari Hitachinaka City 1422.870 3738.88 5452.85
Radiation dose at JAEA Oarai (P11) 1399.370 5409.07
Onuki Oarai Town 1387.990 3882.38 5452.85
Sawa Hitachinaka City 1353.770 2932.21 5450.11
Toyooka Tokai Village 1321.760 3563.48 5452.85
Ajigaura Hitachinaka City 1313.890 3505.9 5450.11
Fukushima [5] (distance from Fukushima I: 45 km) 1282.090 3389.26 5441.9
Geiger Counter Feeds from Asao Kawasaki 1266.620 5362.56
Radiation dose at Tamokami elementary school, Koriyama 1256.140 5384.45
Isohama Oarai Town 1250.540 3384.68 5447.38
Ebisawa Ibaraki Town 1222.240 9188.7 5450.11
Muramatsu Tokai Village 1203.520 3595.39 5452.85
Kamitoda Hokota City 1184.740 2949.66 5452.85
Yanagisawa Hitachinaka City 1166.970 3003.92 5450.11
Tokushuku Hokota City 1159.730 2662.66 5452.85
Tasaki Hokota City 1153.300 3147.43 5422.75
Fukushima [20] (distance from Fukushima I: 45 km) 1145.390 3389.26 5441.9
Kadobe Naka City 1086.580 7155.28 5450.11
Radiation dose at Date city office, Date 1076.050 5387.18
Oshinobe Tokai Village 1041.340 3356.23 5452.85
Oba Mito City 1037.670 11025.3 5452.85
Godai Naka City 1031.270 2909.76 5452.85
Ishikawa Mito City 1030.810 3429.7 5455.58
Isobe Hitachiota City 1013.130 16549.9 5452.85
Yatabe Ibaraki Town 996.127 2877.91 5452.85
Radiation dose at Motomiya city office, Motomiya 992.703 5387.18
Fukushima [73] (distance from Fukushima I: 35 km) 981.984 3384.14 5433.7
Fukushima [75] (distance from Fukushima I: 45 km) 960.529 3384.14 5433.7
Yokobori Naka City 930.280 3372.16 5452.85
Sugaya Naka City 926.186 5152.51 5455.58
Kounosu Naka City 926.087 2630.76 5452.85
Funaishikawa Tokai Village 900.399 3491.74 5452.85
Nukada Naka City 899.900 3153.74 5447.38
Uridura Naka City 890.113 3010.39 5447.38
Shiraki Tsuruga City 881.330 6388.78 5455.58
Motokomezaki Naka City 880.851 2805.1 5420.02
Shiraki pass Tsuruga City 850.284 6691.85 5455.58
Radiation dose in Yamamoto 846.633 5409.07
Yoshizawa Mito City 837.646 3045.32 5452.85
Radiation dose at JAEA Oarai (P7) 831.135 5409.07
Mayumi Hitachiota City 828.119 3021.4 5452.85
Urasoko Tsuruga City 826.465 5304.02 5455.58
Nemoto Hitachioomiya City 825.588 3402.35 5450.11
Takenami Mihama Town 804.283 5567.23 5455.58
Radiation dose at JAEA Oarai (P15) 780.207 5409.07
Tateishi Tsuruga City 780.092 4410.74 5455.58
Radiation dose at JAEA Oarai (P14) 770.174 5409.07
Radiation dose at JAEA Oarai (P13) 769.612 5409.07
Ukishima Kawasaki Ward 735.475 10408.7 5455.58
Kume Hitachiota City 713.958 2957.6 5452.85
Radiation dose at JAEA Oarai (P2) 712.011 5409.07
Fukushima [74] (distance from Fukushima I: 35 km) 706.552 3384.14 5433.7
Nyuu Mihama Town 674.787 5072.74 5455.58
Fukushima [52] (distance from Fukushima I: 40 km) 672.743 3389.26 5441.9
Radiation dose in Iwanuma 670.242 5409.07
Fukushima [51] (distance from Fukushima I: 40 km) 665.376 3389.26 5441.9
Tsuruga Tsuruga City 655.360 4474.54 5455.58
Shiohama Kawasaki Ward 653.536 3573.26 5455.58
Radiation dose in Kakuda 649.863 5409.07
Sakajiri Mihama Town 649.252 5918.21 5455.58
North point of Kinki University Atomic Energy Research Instirute Station 639.566 3716.83 5455.58
Radiation dose in Onagawa (MP-2) 632.968 5406.34
Kumatori town Nishi primary school Station 631.491 4442.62 5455.58
Oshima Kawasaki Ward 630.402 3405.77 5455.58
Izumisano municipal Oike athletic field Station 629.920 5008.94 5455.58
Atom-kyoudou nursery school Station 625.566 4809.53 5455.58
South point of Kinki University Atomic Energy Research Instirute Station 625.202 4378.82 5455.58
Nakamachi Omaezaki City 623.494 5639.02 5455.58
Uraga Yokosuka City 622.492 2671.94 5455.58
Goritoge Shika Town 622.143 5989.99 5455.58
Kumatori town Minami primary school Station 606.134 5096.66 5455.58
Radiation dose at JAEA Oarai (P1) 603.643 5411.81
Yamanotedai-No.1 Park Station 599.140 4753.68 5455.58
Radiation via www.houshasen-pref-ibaraki.jp (unofficial information) 595.502 5428.22
Noumi Shika Town 594.021 5926.15 5455.58
Radiation dose in Watari 591.851 5409.07
Hairando Yokosuka City 588.667 3349.92 5455.58
Fukushima [12] (distance from Fukushima I: 40 km) 588.291 3389.26 5441.9
Ningyotoge Kagamino Town 574.857 4753.68 5455.58
Ten-no Kagamino Town 569.960 5694.86 5455.58
Funagura Yokosuka City 563.909 3158.5 5455.58
Chidori Kawasaki Ward 560.211 3054.79 5455.58
Radiation dose at JAEA Oarai (P16) 556.365 5409.07
Shika Shika Town 551.376 5710.8 5455.58
Higashiosaka municipal Kamikosaka primary scool Station 550.277 3708.84 5455.58
Sahara Yokosuka City 547.404 2959.08 5455.58
Kazanashi Shika Town 545.377 5359.87 5455.58
Akasumi Shika Town 544.970 4905.24 5455.58
Kurahashi Maizuru City 540.820 4466.54 5455.58
Obama Obama City 540.809 3995.98 5455.58
Sakuragaike community hall Omaezaki City 540.772 5782.58 5455.58
Shirowa primary school Omaezaki City 535.692 5662.94 5455.58
Radiation dose at JAEA Oarai (P5) 529.759 5409.07
Uenohara Omaezaki City 529.333 5822.5 5455.58
Kumano Shika Town 529.019 5559.29 5455.58
Izumisano municipal Hineno filtration plant Station 527.471 4793.59 5455.58
Nishi-hamasada Matsue City 525.089 5304 5439.17
Kouno Minami-Echizen Town 525.028 4019.9 5455.58
Kurihama Yokosuka City 523.708 3198.36 5455.58
Osaka prefectural Kumatori off-site-center Station 522.808 4418.69 5455.58
Ogasa branch Kikugawa City 522.039 5887.42 5441.9
Izumisano municipal Hineno primary scool Station 518.181 3836.47 5455.58
Shirasuna Omaezaki City 499.479 5702.86 5455.58
Jitougata primary school Makinohara City 498.059 5471.52 5455.58
Kataku Matsue City 497.007 4251.19 5455.58
Nishihemi Yokosuka City 496.917 2552.3 5455.58
Radiation via www.houshasen-pref-ibaraki.jp (unofficial information) 496.721 5428.22
Satsuma-sendai monitoring center Satsuma-sendai City 495.302 4187.4 5455.58
Otomi Takahama Town 494.821 4689.89 5455.58
Otsu Nanao City 493.895 4705.82 5455.58
The Observation point for comparison Tatsunokuchi 493.454 3876.34 5455.58
Hitsuhama Ohi Town 492.630 4362.89 5455.58
Kijiyama Misasa Town 489.284 4426.68 5455.58
Radiation via www.houshasen-pref-ibaraki.jp (unofficial information) 487.055 5428.22
Hiraba Omaezaki City 485.878 5702.86 5455.58
Tayu Matsue City 484.956 4434.67 5455.58
Hamaokakita primary school Omaezaki City 484.537 5847.66 5441.9
Oitomi Ayabe City 474.670 5623.08 5455.58
Radiation via www.houshasen-pref-ibaraki.jp (unofficial information) 472.017 5428.22
Kashiwazaki-shigai Kashiwazaki City 470.822 4474.54 5455.58
Mitsu Matsue City 466.897 4243.25 5455.58
Tonomachi Kawasaki Ward 463.967 5375.81 5455.58
Daitou branch Kakegawa City 463.829 5760.16 5441.9
Fukura Shika Town 462.493 5351.88 5455.58
Nagasawa Yokosuka City 462.365 3126.58 5455.58
The athletic field Station of Kinki University 461.661 3533.35 5455.58
Koura Matsue City 461.049 5064.74 5455.58
Sakurasan Ward Omaezaki City 459.434 5519.38 5455.58
Tsuchikawa Nanao City 458.915 5208.31 5455.58
Kumatori Town office Station 457.917 3645.05 5455.58
Shinkango Omaezaki City 449.013 6388.78 5455.58
Ogurui Takahama Town 448.279 4179.41 5455.58
Kusabue Omaezaki City 444.162 6021.86 5455.58
Omaezaki City monitoring center 443.946 5910.22 5455.58
Akawase Kagamino Town 442.246 3645.05 5455.58
Ibaraki 442.139 2675.9 5447.38
Hinode Town Yokosuka City 438.324 2105.66 5455.58
Nishiyama Kashiwazaki City 437.251 6332.93 5455.58
Kariwa Kariwa Village 436.307 4777.61 5455.58
Osaka prefectural Hineno high scool Station 435.745 4259.18 5455.58
Miyagawa Kashiwazaki City 435.245 4713.82 5455.58
Radiation dose in Natori 434.640 5409.07
Kami-koubu Matsue City 433.868 4634.04 5455.58
Shimo-Takamachi Kariwa Village 433.192 5200.37 5455.58
Osaka prefectural Sano supporting school Station 432.398 4642.03 5455.58
Arahama Kashiwazaki City 428.874 4857.38 5455.58
Doai Kashiwazaki City 425.681 4570.25 5455.58
Owashi Matsue City 424.452 4530.38 5455.58
Okayasu Maizuru City 422.568 5335.94 5455.58
Katsuyama Kariwa Village 421.280 4857.38 5455.58
Kita-koubu Matsue City 420.683 4969.03 5455.58
Kichisaka Maizuru City 413.065 6484.49 5455.58
Nagai Ohi Town 410.699 4714.7 5447.38
Shiokumi Maizuru City 407.938 8071.73 5455.58
Miyadome Ohi Town 407.831 3908.26 5455.58
Kariwa Kariwa Village 407.617 5032.87 5455.58
Ueno Satsuma-sendai City 394.248 3652.99 5455.58
Power Station-South 389.191 5320.01 5455.58
Radiation dose at JAEA Oarai (P6) 386.963 5409.07
Power Station- 385.546 5192.38 5455.58
Takae Satsuma-sendai City 379.551 3700.85 5455.58
Hokawaduura Genkai Town 378.015 5635.04 5455.58
Kou Itimatsu Suetsugu 377.929 4067.76 5455.58
Minato Satsuma-sendai City 377.656 3389.78 5455.58
Iwanai Iwanai Town 376.336 5524.6 5452.85
Hattari Kyowa Town 373.047 5373.11 5452.85
Chatsu Tomari Village 371.011 5133.95 5452.85
Oyama Maizuru City 358.223 4673.95 5455.58
Kodaira Satsuma-sendai City 355.545 3429.7 5455.58
Kayanuma Tomari Village 354.809 4567.96 5452.85
Anojiri Obama City 353.215 3828.48 5455.58
Kushi Genkai Town 349.738 7776.6 5455.58
Yamaguchi 348.715 6116.35 5447.38
Sadahongou Matsue City 348.228 4761.67 5455.58
Sakibe Karatsu City 347.801 7369.82 5455.58
Hirao Genkai Town 343.814 7768.61 5455.58
The Meteorological Obsevatory of kyowa Town 343.275 5094.11 5452.85
Minami-Horoni Kyowa Town 335.180 4775.21 5452.85
Kounoura Takahama Town 330.353 4035.84 5455.58
Kyoudomarisaki Karatsu City 328.622 7896.24 5455.58
Horikappu Jinja Tomari Village 328.230 4942.62 5452.85
Hukada-kita Matsue City 327.031 3916.2 5455.58
Radiation dose in KEK, Tsukuba 326.240 5428.22
Herokaruusu Tomari Village 324.242 5126.01 5452.85
Yorita Satsuma-sendai City 323.218 4011.91 5455.58
Kamoenai Kamoenai Village 322.032 4328.8 5452.85
Radiation dose in Onagawa (MP-6) 316.267 5406.34
Imamura Genkai Town 314.749 66918.5 5455.58
Yamanaka Takahama Town 314.185 5208.31 5455.58
Sendai (Miyagi) 312.585 2451.32 5447.38
Radiation dose in Onagawa (MP-1) 300.147 5406.34
Gumisaki Satsuma-sendai City 295.693 3238.27 5455.58
Radiation via www.houshasen-pref-ibaraki.jp (unofficial information) 286.142 5428.22
Aomori Aomori City 285.372 3292.42 5452.85
Misawa City hall Misawa City 283.728 6385.57 5452.85
Kashu Ikata Town 277.173 3341.93 5455.58
Noheji Town Office Noheji Town 272.004 2822.09 5452.85
Takasimamati 271.103 3557.28 5455.58
Radiation dose in Onagawa (MP-3) 270.563 5406.34
Kucho Ikata Town 269.545 2951.14 5455.58
Radiation dose in Marumori 269.436 5409.07
Kawanagata Ikata Town 266.821 2879.35 5455.58
Tochigi 260.733 3201.53 5447.38
Chikagawa Mutu City 256.719 3675.08 5452.85
Yokohama Town Office Yokohama Town 254.846 4504.2 5452.85
Tokyo 251.877 3774.94 5447.38
Hiranuma Rokkasho Village 251.186 2957.6 5452.85
Taisei Ikata Town 246.293 2161.51 5455.58
Chitose-daira Rokkasho Village 245.868 3188.82 5452.85
Gifu 243.951 5256.24 5447.38
Fukkoshi Yokohama Town 243.102 3093.15 5452.85
Shimane 240.651 5256.24 5447.38
Sunagomata Higashidoori Village 238.012 4472.29 5452.85
Obuchi Rokkasho Village 237.506 3555.5 5452.85
Tomari Rokkasho Village 230.636 4974.53 5452.85
kanagawa 226.339 3297.1 5447.38
Saitama 219.770 2867.04 5447.38
Ikatagoshi Ikata Town 217.515 2719.8 5455.58
Touhoku Branch office Touhoku Town 215.416 2574.94 5452.85
Radiation dose at Tohoku University 214.824 5409.07
Odanosawa Higashidoori Village 210.287 3563.48 5452.85
Kagawa 205.829 3679.37 5447.38
Oippe Higashidoori Village 205.182 3069.24 5452.85
Oita 200.921 4061.64 5447.38
Touhoku Town office Touhoku Town 200.811 11910.2 5452.85
Kuchogoshi Ikata Town 198.646 2759.71 5455.58
Minatoura Ikata Town 186.776 2480.52 5455.58
Radiation dose in Koyadori, Ojika 184.905 5403.6
Toyama 184.580 7024.25 5447.38
Fukushima [9] (distance from Fukushima I: 45 km) 184.232 3389.26 5441.9
Radiation dose in Tukahama, Ojika 183.417 5403.6
Chiba 182.407 2102.5 5447.38
Nara 182.387 3822.72 5447.38
Okayama 181.976 4969.54 5447.38
Yamagata 181.598 3918.29 5447.38
Ehime 180.745 3536.02 5447.38
Ishikawa 180.445 6092.46 5447.38
Niigata 177.483 7310.95 5447.38
Hiroshima 176.816 3297.1 5447.38
Mie 174.867 3770.16 5447.38
Fukui 170.045 4635.05 5447.38
Radiation dose in Terama, Ojika 168.036 5403.6
Yamanashi 164.561 3058.18 5447.38
Nagano 162.242 4654.16 5447.38
Saga 161.421 4109.42 5447.38
Tottori 161.392 3774.94 5447.38
Radiation dose in Enoshima, Ojika 160.091 5403.6
Osaka 159.103 2914.82 5447.38
Ibaraki-city Environment 157.249 5362.56
Aichi 149.345 3536.02 5447.38
Toyonoura Ikata Town 149.214 2847.43 5455.58
Shizuoka 148.639 3655.48 5447.38
Kyoto 144.522 4157.21 5447.38
Kagoshima 144.449 4506.03 5447.38
Tokushima 143.627 3201.53 5447.38
Gunma 143.572 2150.28 5447.38
Hyogo 139.710 3631.58 5447.38
Fukuoka 136.511 3774.94 5447.38
Wakayama 133.857 2675.9 5447.38
Radiation at Tamaki-cho Mie Japan 133.138 5362.56
Akita 132.832 4109.42 5447.38
Shiga 124.919 2914.82 5447.38
Nagasaki 109.459 3297.1 5447.38
Hokkaido 109.189 5017.32 5447.38
Kumamoto 103.568 3201.53 5447.38
Aomori 101.819 4873.97 5447.38
Miyazaki 100.354 3172.86 5447.38
Kochi 95.931 3631.58 5447.38
Fukushima [35] (distance from Fukushima I: 35 km) 91.917 3380.74 5428.22
Iwate 90.324 4013.86 5447.38
Environment Feeds from Ohta 83.623 5362.56
Okinawa 82.305 2747.58 5447.38
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