Depth Distribution Measurement Results of Radioactive Substances Found at Namie Town, Kawamata Town, and Other Places in Northern Japan Using a Soil Sampler of Large Diameter ( From February 2012 to March 2012 )
- The analysis results show radiation (Bq) per unit weight (kg) and radiation (Bq) per unit volume (m3).
- In order to ascertain the changes of measuring data from the previous survey (the first survey), the same locations that were surveyed in previous measurement were chosen (11 locations). However 3 out of 11 locations had to be changed for the following reasons.
- 1)NM-AKt： Unable to access to the sampling point due to snow coverage (40-60 cm)
- 2)KW-YMk-1： Unable to contact to the land owner to get consent of investigation
- 3)NM-STS-1： Top soil had been removed due to decontamination
The following three measurement points that might reflect the influence of the terrain and ambient surrounding (for example, there is a forest behind the measurement point) were chosen as substitutes. - 1)NM-STS-2-1： Approximately 60 m north from the NM-STS-2 of the first survey
- 2)NM-STS-3-1： Approximately 30 m west from the NM-STS-2 of the first survey
- 3)NM-HR-2-1： Approximately 20 m east from the NM-HR of the first survey
- Regarding the sampling method to avoid contamination of shallower soil with high radioactivity to the deeper one with less radioactivity due to dragging by sampler, surface of soil sample was removed and then center of soil sample was extracted.
- Soil samplings were conducted for 2 cm intervals between surface and a depth of 20 cm, 4 cm intervals between depths of 20 cm and 40 cm, and 5 cm intervals below a depth of 40 cm. The gamma-emitting nuclides were measured by a germanium semiconductor detector (measurement time 60 minutes) after weighing each soil sample.
- Radioactivity concentrations, errors, and detection limit values at time of measurement. "Decay-compensated radioactivity concentration" and "decay-compensated radioactivity concentration in a unit soil volume" are decay-compensated values at time of sampling.
- "ND" in the columns "Radioactivity Concentration", "Decay-compensated Radioactivity Concentration" and "Decay-compensated Radioactivity Concentration in a Unit Soil Volume" , "-" in the column "Error" and "Relative Error", and detection limit values in the column "detection limit": Nuclide analysis results were below the detection limit.
Results of the Measurement of Depth Distribution of Radioactive Substances in Soil at Namie Town, Kawamata Town, etc. ( June 2011 )
- The analysis results show radiation (Bq) per unit weight (kg) and radiation (Bq) per unit volume (m3).
- Soil samplings were conducted at the 11 locations using the Geoslicer.
- Radioactivity concentrations, errors, and detection limit values at time of measurement. "Decay-compensated radioactivity concentration" and "decay-compensated radioactivity concentration in a unit soil volume" are decay-compensated values at time of sampling.
- "ND" in the columns "Radioactivity Concentration", "Decay-compensated Radioactivity Concentration" and "Decay-compensated Radioactivity Concentration in a Unit Soil Volume" , "-" in the column "Error" and "Relative Error", and detection limit values in the column "detection limit": Nuclide analysis results were below the detection limit.
