Measurement result of radiation level (April.28, 22)
Apr.28, 2022 Bureau of Sewerage
Please be informed that Bureau of Sewerage measured current radiation level at boundary of water reclamation centers and radioactivity concentration of incinerator ash and kneaded ash.
1．Radioactivity level on incinerator ash
Sampling Date 3/22/2022-4/11/2022
(1) Incinerator ash
(Bq/kg)
| Water Reclamation Center | 134Cs | 137Cs |
|---|---|---|
| Tobu sludge plant | ND (<21) |
140 |
| Kasai | ND (< 24) |
360 |
| Miyagi | ND (< 22) |
190 |
| Shingashi | ND (<17) |
120 |
| Nanbu sludge plant | ND (< 21) |
86 |
| Kita-Tama Ichigo | ND (< 10) |
68 |
| Minami-Tama | ND (< 10) |
16 |
| Kita-tama Nigo | ND (< 10) |
110 |
| Asakawa | ND (< 10) |
14 |
| Tamagawa Joryu | ND (< 10) |
27 |
| Hachioji | ND (< 10) |
26 |
| Kiyose | ND (< 10) |
22 |
- Analyzed using germanium semiconductor detector (Ge Detector)
- ND : Not detectable
- ( ) : Detection limit
- "Detection limit" refers to the minimum detectable value. For example, a detection limit "<10" means that the minimum measurement is 10 Bq/kg, and "ND" means that the radioactivity concentration incinerator ash is below 10 Bq/kg. "Detection limit" is varied on samples by measurement condition.
(2) Kneaded ash
(Bq/kg)
| Water Reclamation Center | 134Cs | 137Cs |
|---|---|---|
| Nanbu sludge plant | ND (< 17) |
140 |
- "Kneaded ash" is water and cement added incinerator ash for landfill disposal and prevention of scattering
- Analyzed using germanium semiconductor detector (Ge Detector)
-
ND : Not detectable
-
( ) : Detection limit
-
"Detection limit" refers to the minimum detectable value. For example, a detection limit "<16" means that the minimum measurement is 16 Bq/kg, and "ND" means that the radioactivity concentration incinerator ash is below 16 Bq/kg. "Detection limit" is varied on samples by measurement condition.
2．Monitored data on environmental radiation levels
Sampling Date 4/1/2022-4/19/2022
(μSv/h)
| Water Reclamation Center | East Side | West Side | South Side | North Side | Center |
|---|---|---|---|---|---|
| Tobu sludge plant | 0.04 | 0.05 | 0.04 | 0.04 | 0.05 |
| Kasai | 0.05 | 0.04 | 0.05 | 0.04 | 0.05 |
| Miyagi | 0.05 | 0.06 | 0.05 | 0.06 | 0.04 |
| Shingashi | 0.04 | 0.04 | 0.06 | 0.05 | 0.04 |
| Nanbu sludge plant | 0.06 | 0.06 | 0.07 | 0.06 | 0.04 |
| Kita-Tama Ichigo | 0.06 | 0.06 | 0.05 | 0.06 | 0.07 |
| Minami-Tama | 0.06 | 0.04 | 0.03 | 0.05 | 0.04 |
| Kita-tama Nigo | 0.07 | 0.07 | 0.07 | 0.07 | 0.08 |
| Asakawa | 0.04 | 0.05 | 0.05 | 0.05 | 0.06 |
| Tamagawa Joryu | 0.05 | 0.07 | 0.05 | 0.06 | 0.06 |
| Hachioji | 0.06 | 0.06 | 0.07 | 0.07 | 0.08 |
| Kiyose | 0.06 | 0.06 | 0.05 | 0.05 | 0.05 |
※ Measured at a height of 1m using scintillation survey meter at boundaries of water reclamation centers which deal with sludge treatment