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Plastic scintillators (PS) allow design of portative lightweight devices for quantification of low‐activity radiation sources. We have recently suggested a new type of organic fluorophores based on triphenyl pyrazoline (PZ) derivatives with high fluorescence quantum yield showing high radioluminescence when combined with a polyvinyltoluene (PVT) matrix. In this publication we report on radioluminescence properties of the PZ−X family with various halogen substitution (X=F, Cl, Br, I), or having vinyl functional group (vPZ, X=vinyl). PS based on such fluorophores and PVT matrix can be prepared as bulk samples, micrometer size beads or cladding on optical fibers. Application of fluorophores with vinyl functional groups enabled their enhanced interaction with the matrix due to covalent bonding between the components. We demonstrate high performance of PZ−X fluorophores and especially vPZ fluorophore in fabrication of nanocomposites for detection of various types of radiation. Scintillators have enhanced gamma ray detection capabilities with an addition of triphenyl Bi, or Gd2O3 nanoparticles. High fluorescence quantum yield and luminosity of PZ fluorophores allows dramatical reduction of their content in PS systems. Mechanisms of energy transfer and conversion during scintillation process are discussed. Special consideration is given to enhancement of α/β and neutron/gamma (n/γ) pulse shape discrimination (PSD) function of the developed scintillators. [ABSTRACT FROM AUTHOR]

Abstract Water can become contaminated as a result of a leak from a nuclear facility, such as a waste facility, or from clandestine nuclear activity. Low-level on-line radiation monitoring is needed to detect these events in real time. A Bayesian control chart method, Shiryaev-Roberts (SR) procedure, was compared with classical methods, 3- σ and cumulative sum (CUSUM), for quantifying an accumulating signal from an extractive scintillating resin flow-cell detection system. Solutions containing 0.10–5.0 Bq/L of 99Tc, as T 99 cO 4 − were pumped through a flow cell packed with extractive scintillating resin used in conjunction with a Beta-RAM Model 5 HPLC detector. While T 99 cO 4 − accumulated on the resin, time series data were collected. Control chart methods were applied to the data using statistical algorithms developed in MATLAB. SR charts were constructed using Poisson (Poisson SR) and Gaussian (Gaussian SR) probability distributions of count data to estimate the likelihood ratio. Poisson and Gaussian SR charts required less volume of radioactive solution at a fixed concentration to exceed the control limit in most cases than 3- σ and CUSUM control charts, particularly solutions with lower activity. SR is thus the ideal control chart for low-level on-line radiation monitoring. Once the control limit was exceeded, activity concentrations were estimated from the SR control chart using the control chart slope on a semi-logarithmic plot. A linear regression fit was applied to averaged slope data for five activity concentration groupings for Poisson and Gaussian SR control charts. A correlation coefficient (R 2) of 0.77 for Poisson SR and 0.90 for Gaussian SR suggest this method will adequately estimate activity concentration for an unknown solution. Highlights • Shiryaev-Roberts (SR) procedure uses less volume than classical control charts. • Poisson SR uses least volume but could be confused as a false positive. • Gaussian SR has low false positive rate and continuous increasing trend. • Activity concentration can be estimated from SR control chart slope. [ABSTRACT FROM AUTHOR]

Abstract: Combining extraction and scintillation properties within the same material is a relatively new approach in development of sensors for detection of radioactive elements. Structural organization of such materials at a nanoscale typically offers higher efficiency of detection and shorter response time. In this contribution, several new protocols are discussed for fabrication of stable extractive scintillating systems based on commercial Superlig 620 (SL) material with high affinity to radiostrontium. Application of hybrid organic–inorganic beads with SL particles used as core and halloysite clay nanotubes (HNT) modified with a polyvinyltoluene (PVT) brush as a permeable shell combines high‐performance extracting properties of the SL material with efficient light emission properties of the polymer scintillator. The developed SL–HNT–PVT hybrid extractive scintillating material allows real‐time detection of low‐level concentrations of radiostrontium in water. Moreover, the suggested approach is not limited to detection of Sr but can find broader application in development of chemical, biological, or radioluminescent sensors and multifunctional materials. [ABSTRACT FROM AUTHOR]

A novel mesoporous silica-coated ferrocyanide (MSCFC) composite was successfully synthesized and evaluated as a dual-function material for simultaneous removal of 137 Cs + cations and 99 TcO 4 − anions from aqueous solutions. Sorption behavior of both radionuclides on MSCFC under different experimental conditions has been studied using a batch technique. Results revealed that about 100% of 137 Cs + and 97% of 99 TcO 4 − were removed by MSCFC in the pH ranges of 2.2–12.4 and 4.1–9.5, respectively. Sorption kinetic data were analyzed by pseudo-first-order, pseudo-second-order and intraparticle diffusion kinetic models, while Langmuir and Freundlich models were applied for the sorption isotherms. The maximum sorption capacity of MSCFC for radiocesium was determined and compared with other reported sorbents. Applicability of the coated ferrocyanide for simultaneous removal of 137 Cs + and 99 TcO 4 − from low-level liquid radioactive waste (LLLW) was also tested, and the data revealed that 99.91% and 98.34% were removed from 137 Cs + and 99 TcO 4 − , respectively. It is concluded that MSCFC exhibits excellent efficiency for simultaneous removal of the mixed radionuclides with different charge from LLLW. [ABSTRACT FROM AUTHOR]

Abstract: New dual functionality scintillating anion-exchange resins were developed for selective determination of 99TcO4 − in various natural freshwater samples. Stable scintillating particles were formed by preparing the vinyl monomer 2-[4-(4′-vinylbiphenylyl)]-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (vPBD), starting with the commercial organic flour TBut-PBD and its subsequent copolymerization with styrene, divinylbenzene, and p-chloromethylstyrene mixture. To integrate the radiochemical separation and radiometric detection steps within the same bead, the chloromethyl groups of the scintillating resins were subjected to amination reactions with dioctylamine (DOA) and trioctylamine (TOA). On-line quantification of 99TcO4 − was achieved by packing the scintillating anion-exchange resin into Teflon tubing for quantification by a flow scintillation analyzer (FSA). The two functionalized resins were selective for pertechnetate over the common anions in natural freshwaters, especially Cl− and SO4 2− with up to 1000 ppm and with up to 10 ppm I− and Cr2O7 2−. The uptake efficiency of the TOA sensor decreased from 97.88% to 85.08% in well water and river water, respectively, while the counting efficiency was almost constant (69.50%). The DOA performance showed lower efficiency in the two water types relative to TOA. On the other hand, the DOA sensor could be regenerated by 5 M HNO3 for reuse at least four times without losing its chemical or optical performance. The detection limit was 1.45 Bq which could be achieved by loading 45 mL from well and tap water containing the maximum contaminant level (MCL) of 99Tc (33 Bq/L). [Copyright &y& Elsevier]

The present study was oriented to prepare new scintillating anion-exchange resins for measurement of 99TcO4- in natural waters. The organic fluor 2-(1-naphthyl)-5-phenyloxazole was diffused into (chloromethyl)polystyrene resin. Thereafter, a thin layer of poly[[2-(methacryloyloxy)ethyl]trimethylammonium chloride] was grafted from the resin surface by surface-initiated atom transfer radical polymerization as an attempt to overcome potential problems related to the leaching of fluor molecules during usage. The residual chloromethyl groups of the polymer-coated resin were aminated by reaction with two different tertiary amines, triethylamine (TEA) and methyldioctylamine (MDOA). Off- and on-line quantification of 99Tc was achieved with high detection efficiencies of 60.72 ± 1.93% and 72.83 ± 0.81% for resin with TEA and MDOA functional groups, respectively. The detection limit was determined to be less than the maximum contaminant level (33 Bq L-1) established under the Safe Drinking Water Act. The two functionalized resins were demonstrated to be selective for pertechnetate from synthetic groundwater containing up to 1000 ppm Cl-, SO42-, and HCO3- and up to 1200 ppb Cr2O72- in an acidic medium. [ABSTRACT FROM AUTHOR]

Several types of bottled drinking water originating from three different areas in Egypt are studied through measurement of radium activity, assessment of related annual dose for adults and finally to define the role of water quality on radium levels. The mean levels of 226Ra activity range from 0.44 to 0.92Bq/L and the mean levels of 228Ra from 0.30 to 0.78Bq/L, with related 226Ra/228Ra ratios ranging from 2.61 to 0.56. Water types originating from the Eastern Nile Delta area are characterized by low 226Ra levels and relatively high 228Ra activity, presumably due to the muddy agricultural nature of this area, which is subject to water from several surface resources for irrigation. In general, the mean activity levels for both 226Ra and 228Ra are within those in drinking water in several other countries and the annual ingested dose is comparable with the typical range reported by UNSCEAR. Also, the effect of TDS, pH, calcium, bicarbonate, sulphate and chloride ion concentrations on radium levels is studied and discussed. [Copyright &y& Elsevier]

• First application of DGA resins in analytical flow systems. • Achieved ppt limit of detection allows environmental and technological applications. • Fast computer controlled procedure with on-line preconcentration for determination of 239Pu. The monitoring of the presence of plutonium isotopes is a very important issue in both nuclear energy industry and environmental protection for human health risk assessment. The developed method for the determination of 239Pu isotope with ICP-QMS detection is based on the use of sequential injection analysis (SIA) system for the pretreatment of samples to be analyzed with the use of a commercial sorbent called diglycolamide (DGA-b) for the analyte preconcentration and separation from 238U, which is the source of the most significant isobaric interference 238U1H+. Optimizing the size of the sorbent bed and the conditions of analyte sorption and elution of plutonium and uranium provides the analytical procedure for 239Pu determination, where at total analysis time of 45 min (at flow rate 10 mL min−1) the evaluated method detection limit (MDL) for 100 mL sample volume was 88 mBq L−1. This is satisfactory detectability for applications in both technological and environmental samples. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Diglycolamide ligands are widely applied in the analysis of radionuclides, especially lanthanides and actinides. They are used in liquid-liquid extraction procedures or in solid-phase extraction sorbents where they are adsorbed on the surface of hydrophobic polymers. The main objective of this study was to synthesize the N , N , N'N ′-tetrahexyl diglycolamide with one vinyl terminating group (vTHDGA) for further covalent immobilization on the polystyrene-divinylbenzene polymeric support. The obtained complexing resin (THDGA) was employed for the mechanized sample pretreatment in the Sequential Injection Analysis - Lab-on-Valve (SIA-LOV) flow system for the determination of 239Pu using ICP-MS detection. The analytical procedure was optimized in terms of selectivity towards several other radionuclides and elements forming potentially isobaric interferences in mass spectrometry. For 100 mL volume of sample to be analyzed, the method detection limit (MDL) was 96 mBq L−1 (42 pg L−1). The developed method was employed for the determination of 239Pu in real samples of a nuclear reactor coolant and spent fuel pool water from a nuclear reactor. Image 1 • Computer-controlled SIA-LOV setup with an exchangeable sorbent bed • New complexing sorbent for actinides • ICP-MS detection with examination of numerous interferences • Pu-239 determination in samples from nuclear industry [ABSTRACT FROM AUTHOR]