The water-repellent spray treatment without increasing volume was applied for suppressing the elution of radioactive cesium concentrated into the municipal solid waste incineration fly ash. The silane-based oligomer water-repellent was sprayed onto fly ash powder and cementitious fly ash to suppress the elution of radioactive cesium. The elution rate of radioactive cesium from treated fly ash by the Japanese leaching test No.13 was compared to that of non-treated fly ash. The elution rate of water-soluble radioactive cesium was suppressed significantly compared to the elution rate from non-treated fly ash. This method using commercially available water-repellent can be applied to reduce the elution of radioactive cesium from fly ash reclaimed into the landfilled site.
At National Institute for Fusion Science (NIFS), the environmental radioactivity in soil and pine needles were measured from 2014 to 2019 as a part of the monitoring activities for deuterium plasma experiments using Large Helical Device (LHD). Among the monitoring nuclides of 54Mn, 59Fe, 58Co, 60Co, 134Cs, 137Cs, 7Be and 40K, the nuclides of 137Cs, 7Be and 40K were detected by a HPGe detector. The concentration of 40K in soil ranged from 530 Bq/kg to 1,068 Bq/kg, which was the same level at the Tono area reported by Hosoda et al. In addition, the concentration of 40K in pine needles ranged from 125 Bq/kg to 300 Bq/kg and a peak was observed in summer. The maximum concentrations of 7Be on soil and pine needles were 69.4 Bq/kg and 31.9 Bq/kg, respectively. The concentration of 7Be on pine needles became low in summer. Although the concentration of 137Cs on pine needles was not almost detectable, that on soil ranged from 0.56 Bq/kg to 3.69 Bq/kg. The concentrations of these nuclides remain the same level after starting the deuterium plasma experiment in LHD.
As a diagnostic modality, computed tomography (CT) delivers higher radiation doses compared to other imaging modalities. CT requests increase rapidly, hence radiation dose assessment and protection are important. This study assessed the patient radiation dose and estimated organ doses for patients undergoing abdominopelvic CT examination. This study was conducted at three radiology departments equipped with 128-slice CT machines (Philips iCT) calibrated according to international protocols in the West Bank, Palestine. A total of 200 patients underwent abdominopelvic CT examinations. Organ and effective doses were evaluated using a web-based Monte Carlo CT dose calculator: WAZA-ARI dosimetry system that has male and female tissue equivalent phantoms of various ages and sizes. For every patient, a corresponding phantom was selected according to tomographic parameters. For all patients, the colon dose ranged from 5.4 to 26.1 mGy per examination, with a mean colon dose of 14 mGy. The effective dose from abdominopelvic CT scan per examination ranged from 2.04 to 8.4 mSv with an average of 4.8 mSv. It is essential to improve radiographers’ knowledge of radiation dose in CT protocols and to receive continuous education and training regarding radiation dose optimization and reduction strategies.