Problem with Radon Action Level due to the Unattached Radon Decay Products

Seventh Asian Aerosol Conferenc

Radon migration study of the single-layer coverage of the uranium enrichment tailing pond

35th conference Australasian radiation protection societ

Method for Sr-90 Analysis in Environmental Samples Using Thermal Ionization Mass Spectrometry with Daly Ion-Counting System

In this work, a new 90Sr analysis method was developed using the Isotopx Ltd., Phoenix X62 thermal ionization mass spectrometer (TIMS). Excellent ion beam sensitivity was demonstrated with the detection of 1 mBq (0.2 fg) 90Sr on a Daly ion-counting system. The abundance sensitivity for the 90Sr/88Sr ratio was 2.1×10 10 and this could ensure measurement of 100 Bq·kg 1 (19 fg·g 1) 90Sr in an environmental sample with 100 µg·g 1 stable strontium concentration. For analytical method validation, 90Sr was determined in two certified reference materials e.g. wild berry (IRMM-426) and freshwater lake sediment (NIST-4354) for the first time in the history of TIMS. This mass spectrometry method is faster than conventional radiometric techniques; however, interference from 90Zr and peak tailing on the higher mass side from 88Sr must be considered for a reliable 90Sr determination

CESIUM DECONTAMINATION FACTOR DETERMINATION ON DIFFERENT EXTRACTION CHROMATOGRAPHY RESINS

During the nuclear accident of the Fukushima Daiichi Nuclear Power Plant (FDNPP) huge amounts (more than 1017 Bq) of nuclear fission products, such as 131I, 134Cs, 137Cs and 90Sr etc., were released into the atmosphere and the Pacific Ocean1. 137Cs and 90Sr have long-lasting radioecological impact since both have longer half-life (~30 y) than 131I. Furthermore, the 90Sr has a significant biological half-life in the human body. Due to its chemical similarity to calcium, it accumulates in bones and irradiates the bone marrow, causing its high radio-toxicity2. Monitoring 90Sr in the environment is therefore necessary in case of a nuclear disaster. In case of the Fukushima accident, the radioactive contamination in the environment is dominated by radiocesium isotopes (134Cs and 137Cs). In soil samples the magnitudes of these isotopes are around four times higher than the contamination of 90Sr isotope3,4. Radiocesium isotopes emit beta particles and coexist with gamma radiation. Therefore, high effective separation is an essential point for the reliable analysis of the pure beta emitter 90Sr isotope before any radiometric measurement methods. For chemical separation of 90Sr, different procedures are available such as, selective precipitation, liquid-liquid extraction, ion-exchange chromatography and the most popular extraction chromatography. Revealing the high strontium selectivity of crown ethers, an effective and simple extraction chromatography method was developed for strontium separation. In this work cesium decontamination factor of different extraction chromatography resins will be determined using contaminated Fukushima soil samples.9th International Conference on High Level Environmental Radiation Areas-For Understanding Chronic Low-Dose-Rate Radiation Exposure Health Effects and Social Impacts (ICHLERA 2018)に参加し口頭発表をす