[en] Technetium-99 contamination is a big problem in reprocessing of spent and defense nuclear fuel. At the Hanford site in Washington, 500 Ci ⁹⁹Tc has leaked to the environment1-3. Similarly 95 and 31,000 pCi.g^{-1 99}Tc activity has been reported in sediment and water at a field research center Oak Ridge Tennessee. Perrhenate [ReO₄^-] can be used as a surrogate of pertechnetate. These reactions are fairly possible with relatively high thermodynamic feasibility towards the forward direction because ΔE =0.598, is fairly high for Sn⁺² than Fe⁺², so these were the reasons that Sn⁺² was selected as reducing agent. We have tried Sn⁺² to immobilize the Re(VII) to produce low solubility Re(IV) precipitates. In this research, we planned to explore the importance of Sn⁺² as a reducing agent instead of Fe⁺² for the reduction of ReO₄^-. It was explored that precipitate is a complex mixture of SnO₂ and ReO₂ oxides with surface impurity of Sn⁺², SnCl⁺, SnCl₂, and CO₃^-2. The reduced precipitate, has potential application to generate a phase, which has low solubility of Re than ReO₂. This character is important for 99Tc waste management for long term stability of waste form

[en] Technetium-99m (^99mTc) is used in the medical field for diagnosis purposes with a large number of organic carriers. Almost 30 million examinations are conducted worldwide using this isotope, because ^99mTc has a half-life of 6 hours and decays to ^99gTc. Monitoring and safe disposal of ^99gTc from human urine is very important and concern is increasing every day as global use of ^99mTc has increased by more than 4.5x10¹⁴ Bq per week and it is increasing continuously. In 2020, demand is expected to increase 32% as compared to current market demand. Patients’ excretions are discharged to sewer systems without quantification of ^99gTc due to lack of a rapid procedure. Most of the existing ^99gTc analysis procedures are based on purification of the sample matrix, which requires a trained analytical chemist in a hospital or nearby analytical laboratory. It was revealed that in this study, in order to get better sensitivity and lower MDA, ULG is suitable choice for those matrices which are cleaner with negligible quench species. However for quench containing matrices, ULG-LLT performs better than ULG-LLT. Hence samples like urine are better analyzed with ULG-LLT whereas samples like DIW, Tap water, River, and ocean water are suitable with ULG for ^99gTc analysis

[en] The main sources of Strontium-90 in the environment are atmospheric nuclear weapons testing, releases from nuclear accidents, waste tanks and nuclear facilities. It has a physical half-life of 28.8 years and undergoes β-decay (max. beta energy of 545.96 keV) and transforms into its daughter 90Y. Owing to its long physical half-life, 90Sr is one of the most dangerous radionuclides. Its allowed activity in the body is 74 kBq (2 μCi). Numerous methods have been developed for 90Sr analysis. Of these, Ion-exchange method is the simplest one. The objective of present study is to compare solvent extraction using Tributyl Phosphate and the newly developed ion exchange method using cation exchanger with SO3H. Strontium was found to have strong exchange capacity for the locally developed resin and 90Y was eluted in 3mM EDTA under specified pH conditions

[en] The foremost aim of our study is to discuss the unsteady 2D MHD Powell-Eyring flow produced by a flat stretching surface. An incompressible chemical reactive MHD Eyring- Powell fluid immersed in porous medium filled the convective heated stretched sheet with the appearance of nanoparticles. A thorough in- vestigation is performed to study impacts of exothermic, first order chemical reactions and thermal radiation on the fluid flow. This study also assesses the heat and mass boundary conditions. The model utilized for nanoliquid elaborates the influence of thermophoresis and Brownian motion. Moreover, an efficient finite difference method is used and a numerical solution is obtained for the resulting nonlinear PDEs with appro- priate boundary conditions. A detailed discussion regarding how the principal variables affects the flow and thermal fields, is carried out. It is also discussed that how the flow and heat transfer processes is affected by the various parameters of interest. In addition to all this, the physical quantities such as Nusselt number, drag coefficient and mass transfer are calculated keeping in view their significance in engineering. (paper)

[en] The mineral extraction activities may disturb the natural radioactivity, therefore current study aims to generate baseline data of natural radionuclides and anthropogenic ¹³⁷Cs before the start of industrial activities. Gamma spectrometry and gross alpha and beta counting systems were used for activity measurement in environmental samples. In soil, the mean activity of ²³²Th, ²²⁶Ra, ⁴⁰K and ¹³⁷Cs were determined as 79 (66–117), 47 (34–80), 823 (602–1159) and 1.3 (1.1–4.5) Bq kg⁻¹, respectively. The average annual effective dose rate (128.7 µSv h⁻¹) in the study area was twice higher than world’s average value. Indoor hazard index was greater than unity at two places; therefore, proper ventilation is proposed during construction.

[en] Purpose: To determine the feasibility, safety, and efficacy of stereotactic body radiation therapy (SBRT), also known as radiosurgery, in patients with head-and-neck cancers. Methods and Materials: Patients with pathologically proven malignant lesions in the head-and-neck region were treated using single-dose SBRT (S-SBRT) or fractionated SBRT (F-SBRT). Radiation doses were either single-fraction 13-18 Gy for S-SBRT or 36-48 Gy in five to eight fractions for F-SBRT. Response evaluation was based on clinical examinations and computed tomography/magnetic resonance imaging scans. Pre- and post-SBRT tumor dimensions were measured in three axes, and tumor volumes were calculated. Response evaluation also was performed using World Health Organization criteria. Results: Fifty-five lesions were treated in 44 patients (25 men, 19 women). There were three groups of patients: those with primary (n = 10), recurrent (n = 21), and metastatic tumors (n = 13). The predominant histologic type was squamous cell carcinoma (n = 33). The majority of lesions were treated using F-SBRT (n = 37). Based on radiographic and clinical assessment, a 77% (complete + partial response) response rate was noted. Percentage of reduction in tumor volume was 52% ± 38% based on follow-up scans in 24 patients. Tumor control rates at 1 year were 83.3% and 60.6% in the primary and recurrent groups, respectively. Median overall survival was 28.7, 6.7, and 5.6 months for the primary, recurrent, and metastatic groups, respectively. Radiation Therapy Oncology Group Grade 1-2 mucositis was noted in all patients treated for oropharyngeal or laryngeal lesions. Conclusions: The SBRT in single or fractionated doses offers a viable treatment option for selected patients with primary, recurrent, and metastatic head-and-neck cancers with functional preservation.

[en] Cutting-edge research introduces a chemical reactor for liquid radioactive waste treatment, utilizing a four-stage radiochemical separation. Biomass conversion yielded activated carbons with impressive adsorption capacities up to 1 × 10⁴ Bq/g and proved effective for Cs removal. Standout coagulants, AlCl₃·6H₂O and FeSO₄·7H₂O, achieved an 80% decontamination factor for six radionuclides. Sulphonated DVB ion-exchange resins showed high efficiency, achieving 100% Cs decontamination at pH 4 ± 2. Integrated processes successfully decontaminated twelve radionuclides up to 99 ± 1% with substantial demineralization of waste, up to 95%, was achieved. Current reactor system is invaluable for routine and emergency scenarios for treating liquid radioactive waste with varying radionuclide compositions. (author)

[en] Highlights: • Re⁴⁺ was incorporated into SnO₂ particles, called Re(SnO₂). • Re(SnO₂) showed limited re-oxidation and less solubility than ReO₂. • Re¹⁺, Re²⁺, Re⁴⁺, and Re⁷⁺ species were found on Re(SnO₂) surface. • ⁹⁹Tc(SnO₂) can be synthesized like Re(SnO₂) for ⁹⁹Tc immobilization.