Monitoring Data in May, 2011

Regarding the accident at Fukushima nuclear power plant No.1, we started to measure the intensity of radiation.

The place of monitoring, measuring method

The place of monitoring

1-2-1, Sengen, Tsukuba, Ibaraki, 305-0047 JAPAN
(Measuring outdoors. The measuring counter is approximately 1-meter altitude from ground.)


Measuring method

Instrument: NaI scintillation counter, ALOKA TCS-161
Dose rate: values including background level of 0.1 µSv/h


Monitoring Data

Monitoring Data at NIMS Sengen-site

µSv/h (Micro sievert/hour; 1 micro sievert = 1/1000 milli sievert)

Date Dose rate(µSv/h)
May 31, 17:00pm 0.15
May 31, 14:00pm 0.15
May 31, 10:00am 0.15
May 30, 17:00pm 0.15
May 30, 15:00pm 0.15
May 30, 10:00am 0.15
May 29, 15:20pm 0.15
May 29, 08:00am 0.16
May 28, 17:50pm 0.15
May 28, 07:30am 0.15
May 27, 17:00pm 0.14
May 27, 15:00pm 0.15
May 27, 10:00am 0.15
May 26, 17:30pm 0.15
May 26, 14:00pm 0.16
May 26, 10:00am 0.15
May 25, 17:00pm 0.15
May 25, 14:00pm 0.16
May 25, 10:00am 0.15
May 24, 17:00pm 0.15
May 24, 14:00pm 0.15
May 24, 10:00am 0.15
May 23, 17:00pm 0.15
May 23, 14:00pm 0.15
May 23, 10:00am 0.16
May 22, 17:35pm 0.16
May 22, 10:15am 0.15
May 22, 07:00am 0.16
May 21, 17:15pm 0.15
May 21, 10:35am 0.15
May 21, 06:00am 0.15
May 20, 17:00pm 0.15
May 20, 14:00pm 0.15
May 20, 10:00am 0.15
May 19, 17:00pm 0.15
May 19, 14:00pm 0.15
May 19, 10:00am 0.15
May 18, 17:00pm 0.15
May 18, 14:00pm 0.15
May 18, 10:00am 0.15
May 17, 17:00pm 0.16
May 17, 14:00pm 0.15
May 17, 10:00am 0.15
May 16, 17:00pm 0.15
May 16, 14:00pm 0.15
May 16, 10:00am 0.15
May 15, 17:15pm 0.15
May 15, 10:25am 0.15
May 15, 06:00am 0.16
May 14, 17:05pm 0.16
May 14, 14:00pm 0.16
May 14, 09:20am 0.15
May 13, 17:00 pm 0.16
May 13, 14:00 pm 0.15
May 13, 10:00 am 0.15
May 12, 17:00 pm 0.16
May 12, 14:00 pm 0.15
May 12, 10:00 am 0.15
May 11, 17:00 pm 0.15
May 11, 14:00 pm 0.16
May 11, 10:00 am 0.16
May 10, 17:00 pm 0.16
May 10, 14:00 pm 0.16
May 10, 10:00 am 0.16
May 9, 17:00 pm 0.16
May 9, 14:00 pm 0.16
May 9, 10:00 am 0.16
May 8, 17:00 pm 0.16
May 8, 16:05 pm 0.16
May 8, 10:25 am 0.16
May 8, 09:05 am 0.16
May 7, 17:15 pm 0.15
May 7, 16:00 pm 0.15
May 7, 10:20 am 0.16
May 6, 17:00 pm 0.16
May 6, 14:00 pm 0.15
May 6, 10:00 am 0.16
May 5, 17:50 pm 0.15
May 5, 13:00 pm 0.15
May 4, 16:55 pm 0.16
May 4, 14:30 pm 0.16
May 4, 09:25 am 0.16
May 3, 16:15 pm 0.16
May 3, 14:15 pm 0.16
May 3, 09:45 am 0.17
May 2, 17:00 pm 0.16
May 2, 14:00 pm 0.16
May 2, 10:00 am 0.16
May 1, 17:05 pm 0.16
May 1, 15:50 pm 0.16
May 1, 10:00 am 0.16