A silicon PIN diode-based electrostatic collection type online real-time instrument has been developed for simultaneous measurement of radon (222 Rn) and thoron (220 Rn). The system, discussed in this paper, utilizes a hemispherical metal chamber (volume 1 L) for active air sampling. Estimation of 222 Rn/ 220 Rn concentration is carried out through alpha spectroscopy of electro-deposited polonium atoms on the detector surface. The system description and the characterization studies carried out with this instrument are presented here. Its performance has been tested with reference equipments. The instrument showed sensitivity of 0.408 counts per hour (CPH)/(Bq/m 3) and 0.169 CPH/(Bq/m 3) for radon and thoron measurements, respectively, at an optimized collection voltage of + 1.6 kV and relative humidity <10%.
Radiological dispersal devices (RDDs) pose a significant threat due to their ability to release radioactive aerosols into the atmosphere through explosions. The estimation of the respirable fraction of these aerosols by conducting experiments is challenging, and the existing literature on this subject is limited. Modelling the evolution of aerosol particles from a RDD is a complex process due to the contribution of various physical processes at different time scales. In the present study, a comprehensive numerical model is proposed to estimate the respirable fraction of aerosols evolving during the explosion of RDD. The numerical simulations are carried out for different experimental scenarios in the literature, and the model is validated by comparing its results with experimental data of Carbon and Cobalt particles. The average particle diameter of Carbon particles inside the detonation front of TNT predicted by the model is 13.8 nm, which is very close to the experimental observation of 13nm. Further, the model precisely predicted the peak value of the Cobalt particle mass fraction distribution obtained from the experimental data as ~0.7μm. The findings indicate that the present model is capable of predicting the behaviour of radioactive/non-radioactive aerosols. This study emphasize the potential of the modelling approach to address the existing knowledge gaps concerning RDDs. This advancement in understanding can contribute to better impact assessment and management strategies for RDD incidents.
The Bhabha Atomic Research Centre (BARC) is the designated institute in ionizing radiation metrology for the country. The BARC designs, develops, establishes, maintains, and disseminates various national standards for physical quantities of ionizing radiation in India. The IAEA/WHO has recognized the BARC as a Secondary Standard Dosimetry Laboratory (SSDL) for disseminating radiological standards to users in the country. SSDL-BARC provides traceable calibration to the users in the field of teletherapy, brachytherapy, radiation protection, and diagnostic radiology. The pace of the advances in radiation therapy with the expected improvement in patient treatment has brought out the need for greater accuracy in the treatment process. SSDL-BARC participates in international intercomparison programs to establish its equivalence with international standards, thereby validating the calibration procedure followed in the laboratory. Radioisotope targeted therapy has been employed in the treatment of wide variety of cancers. The activity of these radiopharmaceuticals at the nuclear medicine centers is measured using the radionuclide calibrators. BARC as the national metrological laboratory for radioactivity has been conducting the audit program for activity measurements with RC for more than four decades. Neutron sources/fields not only are critical for operating and regulating nuclear reactors but also are important for various other research, industrial, and radiation protection applications. Therefore, precise value of neutron source strength and resultant field is highly essential which is provided by the BARC using several neutron standards developed for the purpose. Radiation processing technologies are very widely used in different industrial applications like sterilization of healthcare products, processing of food and agriculture products, material modification and emerging fields like environmental remediation, synthesis of advanced materials and products, medical applications such as irradiation of blood, etc. Proper dosimetry is the backbone of success of these applications. Conventional radiation measuring techniques like ionization chambers, calorimeters, etc. are unable to measure absorbed doses for most of these applications. Chemical dosimetry techniques provide a cost-effective alternative for radiation processing dosimetry. Radiation monitoring instruments are backbone to all the radiological and nuclear installations for the safety of occupational radiation workers. Performance of these monitors depends on calibration and measurement traceability to the national standards. Protection-level radiation monitors cover a wide range of radiation field (gamma ray, X-ray, and beta ray) intensity and energy; therefore, measurement standards of various types and sizes are established. The BARC has also established various radiological facilities for gamma rays, X-rays, and beta rays which are used for calibration and testing of all kinds of protection-level radiation monitors.
Decision support system (DSS) plays a vital role especially in rural areas to develop rural sector for sustainable development and socio-economic uplifting of the country. To make appropriate decisions and to develop village economy, decision support system is useful for the mandal revenue officer, collector, Surpanch, and different administrators. It deals both spatial and non-spatial data at village level and comprises various ancillary information including mandal maps and village-wise information of Anantapur and Kadapa districts of Andhra Pradesh such as number of houses, male and female, SC/ST/OBC/general (or) OC population, literate and illiterate population, total working and non-working population. Datasets are collected from district collector office, mandal revenue officer (MRO) and inserted in GIS database. This chapter makes an attempt to build features of various decisions at Anantapur and Kadapa districts by integrating various layers of information at village level.
Complementary metal oxide semiconductor (CMOS) camera was used as radiation detector. The methodology to use CMOS active pixel sensor for radiation monitoring purpose is discussed. A new cluster count algorithm to measure dose rates from the images captured using the commonly available CMOS cameras in cell phones and tablets for gamma radiation measurement was developed and implemented on personal computer (PC). Images were taken in standard gamma fields and analyzed on PC to generate the calibration coefficients. The algorithm was validated using 60Co source for dose rates up to 10 Gy/h by images captured on Samsung Galaxy GT-6800 tablet. The algorithm was also tested using other radiation sources such as 137Cs, 241Am, and X-rays for different dose rates.
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