Rabbit Anti-MSV Polyclonal antibody

After the Fukushima Nuclear Power Plant accident, most of radiocesium-contaminated soil generated from decontamination activities outside Fukushima prefecture has been stored at decontamination sites such as schools, parks and residential lands (storage at sites) according to the Decontamination Guidelines. However, additional exposure due to the present storage has not been evaluated. Moreover, entering storage sites, which is not restricted for storage at sites, was not considered in safety assessment conducted in the guidelines. To continue the storage and confirm the effectiveness, understanding of present possible exposures is important. In this study, we evaluated exposure doses for residents and users of storage sites based on the present situation. As a result, annual doses due to residence were 10(-2) to 10(-3) mSv y(-1) and doses due to annual entries were of the order of 10(-3) mSv y(-1). Hence, we confirmed that the exposure due to present storage outside Fukushima is significantly <1 mSv y(-1).

As for all materials of mineral origin, fly ash contains natural radionuclides such as Ra-226, Th-232 and K-40 which contribute to radiation exposure. The present study is aimed to investigate variation of natural radionuclides (Ra-226, Th-232 and K-40) in Ordinary Portland Cement due to variation in the concentration of fly ash. For this purpose, seven cement-fly ash mixtures were experimentally tested for radiological content with NaI(Tl) gamma spectrometer. From the measured gamma-ray spectra, radium equivalent, hazard indices, gamma index, annual effective and gonadal dose were determined. Radium equivalent for samples ranged from 209.53 Bq kg(-1) to 336.06 Bq kg(-1) with a mean of 265.41 Bq kg(-1). The external and internal hazard indices varied from 0.57 to 0.91 Bq kg(-1) and 0.64 to 1.13 Bq kg(-1), respectively. The gamma index exceeded unity for samples with fly ash concentration greater than or equal to 20% by mass. The average annual effective and gonadal dose from different cement-fly ash mixtures was 0.92 mSv y(-1) and 0.95 mSv y(-1), respectively. The study demonstrated that as concentration of fly ash increased in the cement, the concentration of Ra-226 and Th-232 also increased, whereas K-40 content remained the same for all practical purposes.