Local Measurement Results of Ambient Radiation Levels at i Plaza (Updated April 1, 2017)

Measurements of ambient radiation levels were conducted in the i Plaza facility based on the city's policy for measuring ambient radiation levels, and the results are now being published.
In this measurement, there were no areas that require cleaning, as there were no locations exceeding the judgment criterion value (0.23 microsieverts per hour).

Measurement Results (Conducted in Fiscal Year 2016)

i Plaza (Measurement Date: March 10, Weather: Clear)

Measurement Location	Measurement Values (Unit: microsieverts per hour) 1 centimeter above ground
Front Entrance	0.129
Next to the West Side Bicycle Parking	0.074
Art Terrace	0.135
Rainwater Drain Next to Parking Lot	0.070
Parking Lot Grating	0.082

Description

When converted annually, 0.23 microsieverts per hour amounts to 0.99864 millisieverts, which is below the standard value for radiation exposure for the general public during normal times (less than 1 millisievert per year, excluding natural background radiation) as recommended by the International Commission on Radiological Protection (ICRP). Therefore, this value is used as the city's judgment criterion.
According to the Ministry of the Environment's "Decontamination Guidelines," if the radiation level at a depth of 1 meter below the surface is below 0.23 microsieverts per hour, no further action is required. However, our city takes a more cautious approach and makes decisions based on measurement results taken at the closest point to the object (1 centimeter below the surface).

Measurement Overview

Measurer

City Employee

Measuring Equipment

PA-1000

Measurement Method

Average of 5 repeated measurements every 60 seconds

Past Measurement Results

• i Plaza (PDF 49.6KB)