Volume 112, Issue 7-8 - Special Issue: NUCAR-2023

97 Ru is a key radionuclide sought for diagnostic imaging due to its low-energy and intense γ-rays of 215.7 keV and 324.5 keV. New reaction routes to produce this radionuclide are constantly being investigated. A crucial step in carrying out such reactions is a reliable beforehand estimate of the production cross section of radionuclide and optimization conditions through robust theoretical frameworks. Existing literature on α  +  95 Mo reaction has been freshly examined to understand the excitation function of 97 Ru. The data have been compared to other reactions of different projectiles on medium-mass targets. The reaction codes pace 4, empire -3.2.2, and talys -1.96 have been employed to decipher the reaction mechanism and check the predictive ability of underlying theoretical models. The yield of 97 Ru at different projectile energies and thick target yield in the optimum energy range has also been determined from the theoretical modeling.

Excitation functions of alpha-particle induced nuclear reactions on nat Sn have been presented in the 11–40 MeV energy range. In the present study, the stacked-foil activation technique followed by offline gamma-ray spectrometry was used to measure the production of 119 Te, 121 Te, 122 Sb and 126 Sb from alpha-particle induced reactions on nat Sn. The TALYS nuclear code was used to calculate the theoretical predictions of the excitation functions of nat Sn( α ,x) nuclear reactions. The measured data of the above-mentioned nuclear reactions were compared with the theoretical predictions and the experimental results available from EXFOR. In this study, covariance analysis was performed to calculate the uncertainty propagation in the measured cross sections.

Gamma-ray spectrometry-based isotopic composition analysis is a prerequisite for absolute non-destructive assay of Pu by neutron counting or calorimetry. However, gamma-ray spectrometry can be complicated in samples that are heavily shielded or have a high 241 Am fraction. Herein, for the absolute non-destructive assay of Pu, a simple yet potent empirical methodology combining neutron multiplicity counting and calorimetry is proposed, which obviates the need for gamma-ray spectrometry-based isotopic composition analysis. The approach includes stepwise correlation between the parameters obtained from neutron multiplicity counting, i.e.,  α (( α , n ) neutron to spontaneous fission neutron ratio), effective mass of 240 Pu, and D (doubles neutron rate) with the thermal power output ( W Pu ) due to radioactive decay (measured by calorimetry). Because D and  W Pu both are governed by the Pu isotopic composition, their correlation should be sensitive to the isotopic information in a given sample. Mandatory correction for the 241 Am contribution in W Pu was done using the linear plot between its weight fraction and the corresponding α . The proposed methodology was validated by analyzing several PuO 2 standards containing high 241 Am fraction (0.02–0.09). The measured Pu amounts were within 8 % of the actual values with measurement uncertainties between 8 and 10 %, which shows the potential of the proposed methodology for the assay of samples having high 241 Am content or for the quantification of Pu in heavily shielded samples.

Plutonium oxalate supernatant requires a treatment step for further recovery of the residual Pu. As the oxalate ion present in the solution poses problems during the recovery of Pu, it needs to be destroyed. In the present work, Mn 2+ based catalytic destruction of oxalate ion was studied in detail, as it could minimize the generation of secondary radioactive waste compared to the conventional process. The effect of various parameters, namely concentrations of HNO 3 , catalyst, oxalic acid and effect of the metal ion has been studied. Moreover, the robustness of the catalytic destruction method along with the kinetics of oxalate destruction reaction has been investigated. The process was also demonstrated with Pu supernatant generated from CORAL at 1 L scale.

Estimation of Zr in fresh and irradiated metal alloy fuel is important. The homogeneous dissolver solution represents the fuel composition better compared to a highly heterogeneous solid pellet. The present study employs LIBS to determine Zr in the simulated dissolver solution. Four different compositions of U–Zr samples where the Zr/U ratio varies from 0.04 to 0.18 % are analyzed by LIBS with an in-house designed liquid sample cell. A good correlation coefficient is achieved for the measurements in the calibration plot. The results for identifying non-overlapping peaks, calibration plot, precision, deviation, and detection limit are discussed in detail. Two set of solid samples, an oxide pellet and metal alloy with similar Zr/U composition, are also analyzed by LIBS. The results obtained from these three set of samples are inter-compared, and the reason for getting a better Zr/U intensity ratio for a dried coating of sample on aluminium for a given composition is explained.

Metal fuels are considered as the promising candidates for future fast breeder reactors. Pyro-chemical reprocessing is the ideal method for reprocessing spent metallic fuels due to the inherent process advantages. Electrorefining run was demonstrated in a hot cell facility with irradiated U-6 wt% Zr alloy at 500 °C using LiCl–KCl eutectic melt. In order to understand the behavior of the actinides and various fission products during high-temperature electrolysis, various process streams, viz., irradiated metal alloy fuel, the eutectic salt, and the cathode deposit were analyzed for the uranium, plutonium, and other fission product contents. Various methods employed for characterizing the process streams and the behaviors of some of the fission products during the electrolysis process are highlighted. The major gamma emitting radionuclides present in the irradiated fuel were 106 Ru, 125 Sb, 134 Cs, 137 Cs, 144 Ce, and 154 Eu. During electrorefining, cesium, cerium and europium were oxidized and dissolved in the molten media, whereas ruthenium and antimony remained in the anode basket. A minor contamination of zirconium was found in the cathode deposit.

The present paper discusses about the method developed for complete chemical characterization of Zirconium Washed and Dried Frit (WDF) and Reactor Grade ZrO 2 powder which includes nonmetallic element sulphur using Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES). Studies have been carried-out on several important aspects of method development such as effect of matrix on determination of analytes, removal of matrix using different solvents, selection of interference free & sensitive wavelengths, calibration strategies like internal standard & standard addition, optimization of several instrumental parameters which includes RF power, plasma gas flow, nebulizer gas flow, nitrogen purging etc., and are discussed. A % RSD of less than 1 % for Zr and up to 3 % for other elements has been achieved in this method. The developed method has been validated using standard recovery of spiked real time samples with known amount of reference materials. Integrated approach adopted in the development of this method has resulted in reduction of analytical waste generated and also enabled to give quick analytical feedback to production plant for downstream processing.

Boron isotopic ratio measurement is very important in the nuclear industry because it is used as neutron poison (in the form of boric acid or a B 4 C pellet) and control rod material (B 4 C pellet) in nuclear power plants. Since 10 B has a higher neutron absorption cross-section, enriched 10 B is used in the nuclear industry and the extent of enrichment varies from 50–90 %. Therefore, it is essential to determine the 10 B/ 11 B ratio in boric acid and B 4 C. The prime purpose of the present study is to utilize LA-ICPMS for evaluating 10 B/ 11 B ratio both in solution (boric acid) and solid (B 4 C pellet) without any pre-treatment so that the difficulty in dissolution or powdering process of B 4 C (one of the hardest materials) can be avoided and the B 4 C pellet can be reused. The results obtained from LA-ICPMS for the B 4 C pellet are discussed and compared with the solution ICPMS, TIMS, and LIMS. The solutions of boric acid (natural abundance) and dissolved B 4 C (natural & ∼67 % enriched isotopic composition) were analyzed by LA-ICPMS and validated by liquid sampling ICPMS data.

Increasing population, food demands and climatic stressors pose an imminent threat to groundwater sustainability in regional aquifer systems globally. Limited availability of surface water and erratic/uncertain rainfall necessitates preservation of groundwater resources, which form reliable fresh water reserves in most of the arid regions. Bhuj Sandstone aquifer is one such fresh groundwater systems in Western India catering the domestic/irrigational needs for over 2 million population. Rapid groundwater depletion in this area warranted a mandatory conservation of groundwater resources for future sustainability. Nuclear techniques using 3 H and 14 C provide estimates of groundwater age that help in planning sustainable groundwater management. In this study, sustainability of deep groundwater was assessed using environmental radioactive isotopes ( 3 H, 14 C). Results indicate that 14 C activity of the groundwater samples varies from 26 to 73.6 pMC (percent modern carbon). Considering the various biases and uncertainties present, multiple correction models were applied to obtain representative groundwater ages by incorporating stable ( 13 C) isotope and hydrogeochemical data. The corrected and representative ages are found to range from 5.8 to 8.6 ka BP (thousand years before present). From the study it can be inferred that central Bhuj aquifer hosts paleo-groundwater while the western part is recently recharged. Therefore, over-exploitation of deep groundwater in central Bhuj aquifer may further lower the water levels and this would have long-term impact on the socio-economic development of Kutch region.

Cerium hydroxide, Ce(OH) 4 (Ce), has been synthesised and assessed as a Ru-selective adsorbent for treating alkaline radioactive liquid waste. Infrared spectroscopy, thermal analysis, scanning electron microscopy, and energy-dispersive X-ray spectroscopy investigations confirmed the successful formation of nanocrystalline Ce from Ce(NO 3 ) 3 ·6H 2 O. Selective removal of 106 Ru from the ion-exchange effluent of intermediate-level liquid waste (ILW) by Ce was assessed using a high-pure germanium (HPGe) gamma-ray spectrometer. The calculated average distribution coefficient ( k D ) was ∼200 mL/g. The percentage removal of 106 Ru using Ce by varying time, [ 106 Ru] and [Ce] was calculated. The adsorption of 106 Ru on Ce follows pseudo-second-order and Freundlich isotherms. The calculated Q max was 93,584 Bq/g. Accelerated leaching studies of the Ru-laden Ce cement product were carried out and found suitable for transport and disposal. Further, Ce-Polyether sulphone (Ce-PES) and Ce-Chitosan (CeC) composites were prepared and assessed for their Ru-uptake capacity for engineering scale application.

Gallium-68 [ t 1/2 : 67.7 min, β + (89 %)] has application in PET imaging mainly for prostate cancer and neuroendocrine tumours. Gallium-68 is generally obtained from a 68 Ge/ 68 Ga generator. It is therefore an important task to prepare 68 Ge ( t 1/2  = 271 days) radiochemical for the manufacture of 68 Ge/ 68 Ga generator to cater for the needs of various nuclear medicine centres. Germanium-68 has been produced successfully after irradiation of indigenously developed Ga–Ni targets in a 30 MeV cyclotron and chemical processing of the irradiated targets using an indigenous semi-automated module. The Ga–Ni targets were prepared by an electroplating method. The 68 Ge has been radiochemically separated from irradiated Ga–Ni targets using Sephadex G-25 column chromatography. The chemical separation yield and radionuclidic purity of 68 Ge were about 70 % ( n  = 3) and about 98.3 % ( n  = 3), respectively.

Glomerular filtration rate (GFR) could be determined more accurately using renal positron emission tomography (PET) than conventional gamma imaging. Copper-64 [ T ½  = 12.7 h, E β+ (max) = 653 keV, β + branching ratio = 17.8 %, 1346 keV γ-photon (0.54 %), EC (43.8 %), β − emission (38.4 %)] in the form of its hydrophilic complex with 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA) is proposed as a potent formulation for renal PET imaging. A lyophilized kit was developed for formulation of ∼370 MBq dose of [ 64 Cu]Cu–NOTA complex in a facile single step process using 64 Cu produced by thermal neutron activation in a research reactor. The complex could be synthesized with >99 % yield and retained its integrity even when challenged by apoferritin. The rapid accumulation of [ 64 Cu]Cu–NOTA in the kidney and clearance through urinary path was demonstrated using PET/CT imaging and ex vivo biodistribution study carried out in healthy Wistar rats to elucidate its effectiveness as a renal PET-imaging agent.

Synthesis of PSMA-617, a peptide based ligand used in the preparation of nuclear medicine, 177 Lu-PSMA-617, for the treatment of prostate cancer, is demonstrated in 6 steps, starting from appropriately protected amino acid building blocks. A solution phase Boc-strategy was adopted for the synthesis of peptide, wherein deprotection of carbamate group using HCl (g), was employed as the key step. The synthesis furnished PSMA-617 in purity >99.5 % as confirmed by HPLC analysis. ESI-MS and NMR analysis supported the structural integrity of the compound. The synthesized ligand was radiolabelled using 177 Lu to generate the desired radiopharmaceutical, 177 Lu-PSMA-617, in radiochemical purity >98 %, as revealed by radio HPLC and TLC analysis. This establishes its potential as a nuclear medicine for therapeutic application.

A portable liquid scintillation counting system has been used as a rapid screening tool for radiological characterization and in situ measurements of aqueous samples. The methodology was standardized based on the Pulse Length Index for gross α and gross β activity determinations in aqueous solutions by means of a portable Liquid Scintillation Counter (LSC). This single compact PMT system yielded precise results for aqueous test samples, which were validated against a conventional HIDEX 300SL LSC system. The sensitivity of the portable LSC for gross measurements was investigated thoroughly for various combinations of scintillation cocktails and sample proportions, and found to be well below the Operational Intervention Levels (OILs) recommended by Atomic Energy Regulatory Board (AERB) during radiation emergency scenarios. Gross α - and β -activity measurements by means of the portable LSC system have shown this procedure to be effective for preliminary screening and evaluating the total radioactivity in aqueous samples during such radiation emergencies.

The manuscript reports the synthesis of Dy 3+ incorporated lithium magnesium borate glass by melt quenching technique. FTIR study revealed the presence of both BO 3 as well as tetrahedral BO 4 units through their characteristic frequencies. Photoluminescence (PL) study of unirradiated samples confirmed the presence of Dy dopant in the ‘+3’ oxidation states from the characteristic emissions at 482, 578, 666 and 716 nm corresponding to 4 F 9/2 → 6 H 15/2 , 4 F 9/2 → 6 H 13/2 and 4 F 9/2 → 6 H 11/2 , 4 F 9/2 → 6 H 9/2 transitions, respectively. Thermal neutron and gamma irradiated PL emission and lifetime characteristics were discussed in details based on the different defect centers. Thermal neutron irradiated TL study showed that the material has a broad and single dosimetry glow peak at about 450 K which showed high fading due to low temperature peak. TL based neutron sensitivity of LMB: Dy 3+ was found to be about 37.4 times less than that of standard TLD-100 (LiF: Mg, Ti) powder. The net TL response from about 3 to 83 mSv of neutron dose was found to be linear (Adj. R 2  = 0.9994) which is one of the most desirable properties for dosimetry applications. In addition, the TL trap parameters were evaluated using both deconvolution of TL glow curve and peak shape method as suggested by Chen which were found to be matching with each other.